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Gerhard Roth - One of the best experts on this subject based on the ideXlab platform.
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Aversive and non-reward learning in the Fire-Bellied Toad using familiar and unfamiliar prey stimuli
Current Zoology, 2011Co-Authors: Ursula Dicke, Antje Heidorn, Gerhard RothAbstract:The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the Fire-Bellied Toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes) was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presenta- tion of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of Toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in Toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and un- correlated footshock had a stronger aversive effect than correlated footshock (Current Zoology 57 (6): 709-716, 2011).
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Thalamo-telencephalic pathways in the Fire-Bellied Toad Bombina orientalis.
The Journal of comparative neurology, 2008Co-Authors: Frederic Laberge, Sabine Mühlenbrock-lenter, Ursula Dicke, Gerhard RothAbstract:It was suggested that among extant vertebrates, anuran amphibians display a brain organization closest to the ancestral tetrapod condition, and recent research suggests that anuran brains share important similarities with the brains of amniotes. The thalamus is the major source of sensory input to the telencephalon in both amphibians and amniote vertebrates, and this sensory input is critical for higher brain functions. The present study investigated the thalamo-telencephalic pathways in the Fire-Bellied Toad Bombina orientalis, a basal anuran, by using a combination of retrograde tract tracing and intracellular injections with the tracer biocytin. Intracellular labeling revealed that the majority of neurons in the anterior and central thalamic nuclei project to multiple brain targets involved in behavioral modulation either through axon collaterals or en passant varicosities. Single anterior thalamic neurons target multiple regions in the forebrain and midbrain. Of note, these neurons display abundant projections to the medial amygdala and a variety of pallial areas, predominantly the anterior medial pallium. In Bombina, telencephalic projections of central thalamic neurons are restricted to the dorsal striato-pallidum. The bed nucleus of the pallial commissure/thalamic eminence similarly targets multiple brain regions including the ventral medial pallium, but this is accomplished through a higher variety of distinct neuron types. We propose that the amphibian diencephalon exerts widespread influence in brain regions involved in behavioral modulation and that a single dorsal thalamic neuron is in a position to integrate different sensory channels and distribute the resulting information to multiple brain regions. J. Comp. Neurol. 508:806–823, 2008. © 2008 Wiley-Liss, Inc.
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Organization of the sensory input to the telencephalon in the Fire-Bellied Toad, Bombina orientalis.
The Journal of comparative neurology, 2007Co-Authors: Frederic Laberge, Gerhard RothAbstract:The functional organization of sensory activity in the amphibian telencephalon is poorly understood. We used an in vitro brain preparation to compare the anatomy of afferent pathways with the localization of electrically evoked sensory potentials and single neuron intracellular responses in the telencephalon of the Toad Bombina orientalis. Anatomical tracing showed that the anterior thalamic nucleus innervates the anterior parts of the medial, dorsal, and lateral pallia and the rostralmost part of the pallium in addition to the subpallial amygdala/ventral pallidum region. Additional afferents to the medial telencephalon originate from the thalamic eminence. Electrical stimulation of diverse sensory nerves and brain regions generated evoked potentials with distinct characteristics in the pallium, subpallial amygdala/ventral pallidum, and dorsal striatopallidum. In the pallium, this sensory activity is generated in the anterior medial region. In the case of olfaction, evoked potentials were recorded at all sites, but displayed different characteristics across telencephalic regions. Stimulation of the anterior dorsal thalamus generated a pattern of activity comparable to olfactory evoked potentials, but it became similar to stimulation of the optic nerve or brainstem after bilateral lesion of the lateral olfactory tract, which interrupted the antidromic activation of the olfactohabenular tract. Intracellular bimodal sensory responses were obtained in the anterior pallium, medial amygdala, ventral pallidum, and dorsal striatopallidum. Our results demonstrate that the amphibian anterior pallium, medial amygdala/ventral pallidum, and dorsal striatopallidum are multimodal sensory centers. The organization of the amphibian telencephalon displays striking similarities with the brain pathways recently implicated in mammalian goal-directed behavior.
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Organization of the pallium in the Fire-Bellied Toad Bombina orientalis. I: Morphology and axonal projection pattern of neurons revealed by intracellular biocytin labeling.
The Journal of Comparative Neurology, 2007Co-Authors: Gerhard Roth, Frederic Laberge, Sabine Mühlenbrock-lenter, Wolfgang GrunwaldAbstract:The cytoarchitecture and axonal projection pattern of pallial areas was studied in the Fire-Bellied Toad Bombina orientalis by intracellular injection of biocytin into a total of 326 neurons forming 204 clusters. Five pallial regions were identified, differing in morphology and projection pattern of neurons. The rostral pallium receiving the bulk of dorsal thalamic afferents has reciprocal connections with all other pallial areas and projects to the septum, nucleus accumbens, and anterior dorsal striatum. The medial pallium projects bilaterally to the medial pallium, septum, nucleus accumbens, mediocentral amygdala, and hypothalamus and ipsilaterally to the rostral, dorsal, and lateral pallium. The ventral part of the medial pallium is distinguished by efferents to the eminentia thalami and the absence of contralateral projections. The dorsal pallium has only ipsilateral projections running to the rostral, medial, and lateral pallium; septum; nucleus accumbens; and eminentia thalami. The lateral pallium has ipsilateral projections to the olfactory bulbs and to the rostral, medial, dorsal, and ventral pallium. The ventral pallium including the striatopallial transition area (SPTA) has ipsilateral projections to the olfactory bulbs, rostral and lateral pallium, dorsal striatopallidum, vomeronasal amygdala, and hypothalamus. The medial pallium can be tentatively homologized with the mammalian hippocampal formation, the dorsal pallium with allocortical areas, the lateral pallium rostrally with the piriform and caudally with the entorhinal cortex, the ventral pallium with the accessory olfactory amygdala. The rostral pallium, with its projections to the dorsal and ventral striatopallidum, resembles the mammalian frontal cortex.
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The septal complex of the Fire-Bellied Toad Bombina orientalis: chemoarchitecture.
Journal of chemical neuroanatomy, 2005Co-Authors: Heike Endepols, Gerhard Roth, Sabine Mühlenbrock-lenter, Wolfgang WalkowiakAbstract:Abstract In order to investigate whether chemoarchitecture would support the subdivision of the anuran septum based on cytoarchitectonic and hodological studies, we performed enzyme-histochemical detection of NADPH-diaphorase and immunohistological demonstration of choline-acetyl transferase (ChAT), aspartate, calretinin, γ-aminobutyric acid (GABA), 5-hydroxy-tryptamine, tyrosine hydroxylase, neuropeptide Y (NPY), somatostatin, Leu- and Leu + Met-enkephalin, and substance P in the Fire-Bellied Toad Bombina orientalis . Labeling of cell bodies matched well the previously defined subnuclei: The dorsolateral septal nucleus contains enkephalin-immunoreactive (-ir) and weakly stained GABA-ir neurons; calretinin-ir and weakly labeled GABA-ir neurons are found in the ventrolateral septal nucleus. The medial septal nucleus is characterized by the presence of numerous ChAT-ir and some tyrosine hydroxylase-ir neurons, while the dorsal septal nucleus is outlined by its NPY-ir neurons. Many ChAT-ir and some aspartate-ir and somatostatin-ir neurons are found in the diagonal band of Broca, and the central septal nucleus contains some GABA-ir and ChAT-ir neurons. In contrast, labeled fibers form a pattern which does not match the boundaries of septal subnuclei. Comparing the anuran septal complex with that of other vertebrates reveals that the complexity of the lateral septum has increased during the evolution from anamniote to amniote vertebrates. In spite of this fact, many similarities in chemoarchitecture between anurans and other vertebrates are evident. Some basal septal functions such as involvement in learning and memory formation or inhibition of sexual behavior appear to have persisted during vertebrate evolution.
Frederic Laberge - One of the best experts on this subject based on the ideXlab platform.
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Temporal Profile of Brain Gene Expression After Prey Catching Conditioning in an Anuran Amphibian.
Frontiers in neuroscience, 2020Co-Authors: Vern Lewis, Frederic Laberge, Andreas HeylandAbstract:A key goal in modern neurobiology is to understand the mechanisms underlying learning and memory. To that end, it is essential to identify the patterns of gene expression and the temporal sequence of molecular events associated with learning and memory processes. It is also important to ascertain if and how these molecular events vary between organisms. In vertebrates, learning and memory processes are characterized by distinct phases of molecular activity involving gene transcription, structural change, and long-term maintenance of such structural change in the nervous system. Utilizing next generation sequencing techniques, we profiled the temporal expression patterns of genes in the brain of the Fire-Bellied Toad Bombina orientalis after prey catching conditioning. The Fire-Bellied Toad is a basal tetrapod whose neural architecture and molecular pathways may help us understand the ancestral state of learning and memory mechanisms in tetrapods. Differential gene expression following conditioning revealed activity in molecular pathways related to immediate early genes (IEG), cytoskeletal modification, axon guidance activity, and apoptotic processes. Conditioning induced early IEG activity coinciding with transcriptional activity and neuron structural modification, followed by axon guidance and cell adhesion activity, and late neuronal pruning. While some of these gene expression patterns are similar to those found in mammals submitted to conditioning, some interesting divergent expression profiles were seen, and differential expression of some well-known learning-related mammalian genes is missing altogether. These results highlight the importance of using a comparative approach in the study of the mechanisms of leaning and memory and provide molecular resources for a novel vertebrate model in the relatively poorly studied Amphibia.
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Determinants of the water seeking response in a T-maze in the Fire-Bellied Toad Bombina orientalis
Learning and Motivation, 2020Co-Authors: Sarah Ouellet, Amber Lavictoire, Frederic LabergeAbstract:Abstract To maintain water balance, terrestrial amphibians are motivated to seek water when dehydrated and to avoid hypertonic solutions that promote water loss to the environment. Thus, dehydration and hypertonic solutions both act to promote positive water balance through opposite appetitive and aversive mechanisms. In one experiment, we tested if appetitive and aversive stimuli interact to facilitate learning of the location of a water source in the Fire-Bellied Toad Bombina orientalis. Dehydrated and hydrated Toads were placed in a T-maze with accessible distilled water in one arm and hypertonic saline or inaccessible water in the other arm. Maze performance was assessed by measuring time to find the water source and correct first choices over 6 consecutive days of training. Results showed reduced time to find water in dehydrated Toads but no reliable improvement in correct first choices that would indicate spatial learning. Hypertonic saline inhibited maze exploration but otherwise had no effect on performance. Because we expected spatial learning for water based on previous work in this species (Brattstrom, 1990 J Herpetol 24:44−47), we conducted a second experiment with longer training, again including dehydrated and hydrated Toads. Maze training for four weeks with four weekly trials revealed a rapid reduction in time to find water in dehydrated Toads followed later by an improvement in correct first choices suggestive of spatial learning. Additionally, changing the motivational status of Toads after the four-week training period showed no evidence that hydrated Toads had learned location of the water source during training. Our results suggest that both motivational and learning effects ameliorated water seeking behaviour in this terrestrial amphibian, but that motivation acted much faster than learning. Additionally, Toads that experienced no reinforcement during training showed no latent learning effect.
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Efferent Axonal Projections of the Habenular Complex in the Fire-Bellied Toad Bombina orientalis
Brain behavior and evolution, 2017Co-Authors: Frederic Laberge, Allison SmithAbstract:The habenular complex and its associated axonal pathways are often thought of as phylogenetically conserved features of the brain among vertebrates despite the fact that detailed studies of this brain region are limited to a few species. Here, the gross morphology and axonal projection pattern of the habenular complex of an anuran amphibian, the Fire-Bellied Toad Bombina orientalis, was studied to allow comparison with the situation in other vertebrates. Axonal pathways were traced using biocytin applications in dissected brain preparations. The results show that the rostral part of the left dorsal nucleus is enlarged in this species, while the rostral ventral nucleus and caudal parts do not show left-right size differences. Biocytin applications revealed widespread axonal projections of the habenular complex to the posterior tuberculum/dorsal hypothalamic region, ventral tegmentum, interpeduncular nucleus (IPN), and raphe median. Additionally, axons targeting the lateral hypothalamus originated from the ventral habenular nuclei. The results also suggest an asymmetrical pattern of projection to the IPN in the rostral part of the habenular complex, where the left habenula preferentially targeted the dorsal IPN while the right habenula preferentially targeted the ventral IPN. The caudal habenular nuclei showed no asymmetry of projections as both sides targeted the ventral IPN. Comparison of the habenular complex axonal connectivity across vertebrates argues against strong phylogenetic conservation of the axonal projection patterns of different habenular nuclei.
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Organization of afferents to the striatopallidal systems in the Fire-Bellied Toad Bombina orientalis
Brain Structure and Function, 2014Co-Authors: Zachary J. Ramsay, Frederic LabergeAbstract:The cerebral hemispheres of amphibians display paired dorsal and ventral striatum (commonly referred to as striatum proper and nucleus accumbens, respectively). Each striatal region is proposed to be closely associated with a pallidal structure located caudal to it to form a striatopallidal system. In the present study, afferents to the dorsal and ventral striatopallidal systems of the Fire-Bellied Toad ( Bombina orientalis ) were investigated using the neuronal tracer biocytin. A quantitative analysis of the topographical distribution of afferent neurons from the thalamus and posterior tubercle/ventral tegmentum was emphasised. The main results show that inputs to the two striatopallidal systems originate from distinct dorsal thalamic nuclei, with dorsal and ventral striatopallidal afferent neurons favouring strongly the lateral/central and anterior thalamic nuclei, respectively. However, afferent neuron distribution in the dorsal thalamus does not differ in the rostrocaudal axis of the brain. Afferent neurons from the posterior tubercle and ventral tegmentum, on the other hand, are organised topographically along the rostrocaudal axis. About 85 % of afferent neurons to the dorsal striatopallidal system are located rostrally in the posterior tubercle, while 75 % of afferent neurons to the ventral striatopallidal system are found more caudally in the ventral tegmentum. This difference is statistically significant and confirms the presence of distinct mesostriatal pathways in an amphibian. These findings demonstrate that an amphibian brain displays striatopallidal systems integrating parallel streams of sensory information potentially under the influence of distinct ascending mesostriatal pathways.
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Illness-dependent conditioned prey avoidance in an amphibian.
Behavioural processes, 2014Co-Authors: Frederic LabergeAbstract:Conditioned taste avoidance (CTA) helps prevent consumption of dangerous foods. It results from the pairing of a novel food or taste with subsequent aversive consequences, such as illness. Previous studies of CTA in amphibians have produced conflicting results. Establishing the presence or absence of CTA in amphibians is needed to clarify the phylogeny of this phenomenon. This experiment evaluated the ability of the Fire-Bellied Toad Bombina orientalis to avoid a novel food item previously paired with subsequent illness or unpalatable taste. Mealworms, a novel prey item for the subjects, were coated with a solution of either 2% HCl or 3% CuSO4 to make them unpalatable or nauseating, respectively. Lengthy and obvious signs of illness such as face wiping and retching followed the consumption of mealworms coated with CuSO4, whereas consumption of mealworms coated with HCl only resulted in distinct and short lived aversive reactions at the time of consumption. The results showed that consumption of mealworms tainted with CuSO4, but not HCl, rapidly induced prey avoidance. This response was specific to mealworms; the usual food (crickets) was not avoided. The results suggest that CTA following illness is not restricted to amniote vertebrates.
Ursula Dicke - One of the best experts on this subject based on the ideXlab platform.
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Aversive and non-reward learning in the Fire-Bellied Toad using familiar and unfamiliar prey stimuli
Current Zoology, 2011Co-Authors: Ursula Dicke, Antje Heidorn, Gerhard RothAbstract:The present study investigated how snapping behavior toward familiar and unfamiliar prey is modified by reward omission and aversive conditioning in the Fire-Bellied Toad Bombina orientalis. Toads were trained to snap at cricket images by rewarding them with live crickets. The task was learned, and the learning criterion (10 snapping responses within 2 minutes) was reached in all individuals investigated. Subsequent reward omission did not alter the frequency of snapping to the familiar cricket stimulus. Snapping decreased only in some individuals, when a mild foot shock was applied at snapping. However, at presenta- tion of images of hitherto unfamiliar meal worms and foot-shock application at snapping to the stimulus, the majority of Toads diminished snapping significantly. Snapping responses decreased more rapidly, when snapping at meal worms was not rewarded or a footshock was applied uncorrelated to the presentation of or snapping at meal worms. These results demonstrate that in Toads familiarity and unfamiliarity of prey stimuli are important factors in aversive learning, because well-trained responses to familiar stimuli become immune against reward omission. Furthermore, at presentation of unfamiliar stimuli, omission of reward and un- correlated footshock had a stronger aversive effect than correlated footshock (Current Zoology 57 (6): 709-716, 2011).
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Thalamo-telencephalic pathways in the Fire-Bellied Toad Bombina orientalis.
The Journal of comparative neurology, 2008Co-Authors: Frederic Laberge, Sabine Mühlenbrock-lenter, Ursula Dicke, Gerhard RothAbstract:It was suggested that among extant vertebrates, anuran amphibians display a brain organization closest to the ancestral tetrapod condition, and recent research suggests that anuran brains share important similarities with the brains of amniotes. The thalamus is the major source of sensory input to the telencephalon in both amphibians and amniote vertebrates, and this sensory input is critical for higher brain functions. The present study investigated the thalamo-telencephalic pathways in the Fire-Bellied Toad Bombina orientalis, a basal anuran, by using a combination of retrograde tract tracing and intracellular injections with the tracer biocytin. Intracellular labeling revealed that the majority of neurons in the anterior and central thalamic nuclei project to multiple brain targets involved in behavioral modulation either through axon collaterals or en passant varicosities. Single anterior thalamic neurons target multiple regions in the forebrain and midbrain. Of note, these neurons display abundant projections to the medial amygdala and a variety of pallial areas, predominantly the anterior medial pallium. In Bombina, telencephalic projections of central thalamic neurons are restricted to the dorsal striato-pallidum. The bed nucleus of the pallial commissure/thalamic eminence similarly targets multiple brain regions including the ventral medial pallium, but this is accomplished through a higher variety of distinct neuron types. We propose that the amphibian diencephalon exerts widespread influence in brain regions involved in behavioral modulation and that a single dorsal thalamic neuron is in a position to integrate different sensory channels and distribute the resulting information to multiple brain regions. J. Comp. Neurol. 508:806–823, 2008. © 2008 Wiley-Liss, Inc.
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morphology axonal projection pattern and responses to optic nerve stimulation of thalamic neurons in the fire bellied Toad bombina orientalis
The Journal of Comparative Neurology, 2003Co-Authors: Gerhard Roth, Wolfgang Grunwald, Ursula DickeAbstract:Intracellular recording and biocytin labeling were carried out in the Fire-Bellied Toad Bombina orientalis to study the morphology and axonal projections of thalamic (TH) neurons and their responses to electrical optic nerve stimulation. Labeled neurons (n = 142) were divided into the following groups: TH1 neurons projecting to the dorsal striatum; TH2 neurons projecting to the amygdala, nucleus accumbens, and septal nuclei; TH3 neurons projecting to the medial or dorsal pallium; TH4 neurons with projections ascending to the dorsal striatum or ventral striatum/amygdala and descending to the optic tectum, tegmentum, and rostral medulla oblongata; TH5 neurons with projections to the tegmentum, rostral medulla oblongata, prectectum, or tectum; and TH6 neurons projecting to the hypothalamus. TH1 neurons are found in the central, TH2 neurons in the anterior and central, TH3 neurons in the anterior dorsal nucleus, and TH4 and TH5 neurons in the posterior dorsal or ventral nucleus. Neurons with descending projections arborize in restricted parts of retinal afferents; neurons with ascending projections do not substantially arborize within retinal afferents. At electrical optic nerve stimulation, neurons in the ventral thalamus respond with excitation at latencies of 10.8 msec; one-third of them follow repetitive stimulation and possibly are monosynaptically driven. Neurons in the dorsal thalamus respond mostly with inhibition at latencies of 42.3 msec and are polysynaptically driven. This corroborates the view that neurons in the dorsal thalamus projecting to the telencephalon receive no substantial direct retinal input and that the thalamopallial pathway of amphibians is not homologous to the mammalian retinogeniculocortical pathway. J. Comp. Neurol. 461:91–110, 2003. © 2003 Wiley-Liss, Inc.
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Morphology, axonal projection pattern, and responses to optic nerve stimulation of thalamic neurons in the Fire-Bellied Toad Bombina orientalis.
The Journal of comparative neurology, 2003Co-Authors: Gerhard Roth, Wolfgang Grunwald, Ursula DickeAbstract:Intracellular recording and biocytin labeling were carried out in the Fire-Bellied Toad Bombina orientalis to study the morphology and axonal projections of thalamic (TH) neurons and their responses to electrical optic nerve stimulation. Labeled neurons (n = 142) were divided into the following groups: TH1 neurons projecting to the dorsal striatum; TH2 neurons projecting to the amygdala, nucleus accumbens, and septal nuclei; TH3 neurons projecting to the medial or dorsal pallium; TH4 neurons with projections ascending to the dorsal striatum or ventral striatum/amygdala and descending to the optic tectum, tegmentum, and rostral medulla oblongata; TH5 neurons with projections to the tegmentum, rostral medulla oblongata, prectectum, or tectum; and TH6 neurons projecting to the hypothalamus. TH1 neurons are found in the central, TH2 neurons in the anterior and central, TH3 neurons in the anterior dorsal nucleus, and TH4 and TH5 neurons in the posterior dorsal or ventral nucleus. Neurons with descending projections arborize in restricted parts of retinal afferents; neurons with ascending projections do not substantially arborize within retinal afferents. At electrical optic nerve stimulation, neurons in the ventral thalamus respond with excitation at latencies of 10.8 msec; one-third of them follow repetitive stimulation and possibly are monosynaptically driven. Neurons in the dorsal thalamus respond mostly with inhibition at latencies of 42.3 msec and are polysynaptically driven. This corroborates the view that neurons in the dorsal thalamus projecting to the telencephalon receive no substantial direct retinal input and that the thalamopallial pathway of amphibians is not homologous to the mammalian retinogeniculocortical pathway.
Ralph Tiedemann - One of the best experts on this subject based on the ideXlab platform.
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Introgression of Austrian Fire-Bellied Toads (Bombina bombina) into northern German populations confirmed by complete mitochondrial genomes and transcriptome-wide Single Nucleotide Polymorphisms (SNPs)
2019Co-Authors: Binia De Cahsan, Michael V. Westbury, Hauke Drews, Sofia Paraskevopoulou, Moritz Ott, Guenter Gollmann, Ralph TiedemannAbstract:Abstract The Fire-Bellied Toad (Bombina bombina) is a small amphibian species inhabiting the lowlands of Central and Eastern Europe. Continual population fragmentation has caused a decrease in genetic diversity and gene flow in margin populations in Northern Germany. Previous research using mitochondrial control region data uncovered a translocation of allochthonous Toads from Austria into a single northern German population, Hogsdorf. Microsatellite and MHC data also confirmed this introgression, but were limited in revealing the true extent of this translocation for all investigated populations. Here, we utilize complete mitochondrial genomes and nuclear data, in the form of transcriptomes, to unravel the full extent of admixture from this translocation. The increased number of loci enabled us to uncover signs of introgression in four out of the five northern populations investigated. Moreover, as hybrids between B. bombina and its sister species, B. variegata, have been reported in Austria, we also investigated whether B. variegata alleles were translocated into the northern gene pool. We found evidence for hybridization between Austrian B. bombina and B. variegata, as well as traces of B. variegata alleles in one of the five German populations included in this study. These findings present the first reported case of introgressed relict B. variegata alleles from the Southern lineage being detected in Northern Germany.
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The complete mitochondrial genome of a European Fire-Bellied Toad (Bombina bombina) from Germany
Mitochondrial DNA Part B, 2019Co-Authors: Binia De Cahsan, Michael V. Westbury, Hauke Drews, Ralph TiedemannAbstract:AbstractThe European Fire-Bellied Toad, Bombina bombina, is a small aquatic Toad belonging to the family Bombinatoridae. The species is native to the lowlands of Central and Eastern Europe, where p...
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Environmental niche factor analysis (ENFA) relates environmental parameters to abundance and genetic diversity in an endangered amphibian, the Fire-Bellied-Toad (Bombina bombina)
Conservation Genetics, 2014Co-Authors: N. Dolgener, L. Freudenberger, N. Schneeweiss, P. L. Ibisch, M. Schluck, Ralph TiedemannAbstract:Increasing attempts are made to understand the factors responsible for both the demographic and genetic depletion in amphibian populations. Landscape genetics aims at a spatially explicit correlation of genetic population parameters to landscape features. Using data from the endangered Fire-Bellied Toad Bombina bombina in Brandenburg (Northeastern Germany), we performed an environmental niche factor analysis (ENFA), relating demographic (abundance) and genetic (diversity at 17 microsatellite loci and partial sequences of the mitochondrial control region in 434 individuals from 16 populations) parameters to ecological and anthropogenic variables such as temperature, precipitation, soil wetness, water runoff, vegetation density, and road/traffic impact. We found significant correlations between road disturbance and observed heterozygosity and between soil wetness and mitochondrial diversity. As the influences of the environmental variables can differ between different indicators for genetic diversity, population size and abundance data, our ENFA-based landscape genetics approach allows us to put various aspects of long- versus short term effective population size and genetic connectivity into an ecological and spatially explicit context, enabling potentially even forecast assessment under future environmental scenarios.
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Genetic population structure of the Fire-Bellied Toad Bombina bombina in an area of high population density: implications for conservation
Hydrobiologia, 2012Co-Authors: Nicola Dolgener, N. Schneeweiss, Christiane Schröder, Ralph TiedemannAbstract:In this study, we report the genetic population structure of the Fire-Bellied Toad Bombina bombina in Brandenburg (East Germany) in the context of conservation. We analysed 298 samples originating from 11 populations in Brandenburg using mitochondrial control region sequences and six polymorphic microsatellite loci. For comparison, we included one population each from Poland and Ukraine into our analysis. Within Brandenburg, we detected a moderate variability in the mitochondrial control region (19 different haplotypes) and at microsatellite loci (9–12 alleles per locus). These polymorphisms revealed a clear population structure among Toads in Brandenburg, despite a relatively high overall population density and the moderate size of single populations (100–2000 individuals). The overall genetic population structure is consistent with a postglacial colonization from South East-Europe and a subsequent population expansion. Based on genetic connectivity, we infer Management Units (MUs) as targets for conservation. Our genetic survey identified MUs, within which human infrastructure is currently preventing any genetic exchange. We also detect an unintentional translocation from South East to North West Brandenburg, presumably in the course of fish stocking activities. Provided suitable conservation measures are taken, Brandenburg should continue to harbor large populations of this critically endangered species.
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Allochthonous individuals in managed populations of the Fire-Bellied Toad Bombina bombina: Genetic detection and conservation implications
Limnologica, 2012Co-Authors: Christiane Schröder, Hauke Drews, Nicola Dolgener, Ina Pokorny, Christoph Herden, Ralph TiedemannAbstract:The ongoing global amphibian decline calls for an increase of habitat and population management efforts. Pond restoration and construction is more and more accompanied by breeding and translocation programs. However, the appropriateness of translocations as a tool for conservation has been widely debated, as it can cause biodiversity loss through genetic homogenization and can disrupt local adaptation, eventually leading to outbreeding depression. In this study, we investigated the genetic structure of two translocated populations of the critically endangered Fire-Bellied Toad Bombina bombina at its north western distribution edge using supposedly neutral genetic markers (variation in the mitochondrial control region and microsatellites) as well as a marker under selection (major histocompatibility complex (MHC) genes). While one of the newly established populations showed the typical genetic composition of surrounding populations, the other was extremely diverged without clear affinity to its putative source. In this population we detected a profound impact of allochthonous individuals: 100% of the analyzed individuals exhibited a highly divergent mitochondrial haplotype which was otherwise found in Austria. 83% of them were also assigned to Austria by the analysis of microsatellites. Interestingly, for the adaptive marker (MHC) local alleles were predominant in this population, while only very few alleles were shared with the Austrian population. Probably Mendelian inheritance has reshuffled genotypes such that adaptive local alleles are maintained (here, MHC), while presumably neutral allochthonous alleles dominate at other loci. The release of allochthonous individuals generally increased the genetic variability of the affected population without wiping out locally adaptive genotypes. Thus, outbreeding depression might be less apparent than sometimes thought and natural selection appears strong enough to maintain locally adaptive alleles, at least in functionally important immune system genes.
Wolfgang Grunwald - One of the best experts on this subject based on the ideXlab platform.
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Organization of the pallium in the Fire-Bellied Toad Bombina orientalis. I: Morphology and axonal projection pattern of neurons revealed by intracellular biocytin labeling.
The Journal of Comparative Neurology, 2007Co-Authors: Gerhard Roth, Frederic Laberge, Sabine Mühlenbrock-lenter, Wolfgang GrunwaldAbstract:The cytoarchitecture and axonal projection pattern of pallial areas was studied in the Fire-Bellied Toad Bombina orientalis by intracellular injection of biocytin into a total of 326 neurons forming 204 clusters. Five pallial regions were identified, differing in morphology and projection pattern of neurons. The rostral pallium receiving the bulk of dorsal thalamic afferents has reciprocal connections with all other pallial areas and projects to the septum, nucleus accumbens, and anterior dorsal striatum. The medial pallium projects bilaterally to the medial pallium, septum, nucleus accumbens, mediocentral amygdala, and hypothalamus and ipsilaterally to the rostral, dorsal, and lateral pallium. The ventral part of the medial pallium is distinguished by efferents to the eminentia thalami and the absence of contralateral projections. The dorsal pallium has only ipsilateral projections running to the rostral, medial, and lateral pallium; septum; nucleus accumbens; and eminentia thalami. The lateral pallium has ipsilateral projections to the olfactory bulbs and to the rostral, medial, dorsal, and ventral pallium. The ventral pallium including the striatopallial transition area (SPTA) has ipsilateral projections to the olfactory bulbs, rostral and lateral pallium, dorsal striatopallidum, vomeronasal amygdala, and hypothalamus. The medial pallium can be tentatively homologized with the mammalian hippocampal formation, the dorsal pallium with allocortical areas, the lateral pallium rostrally with the piriform and caudally with the entorhinal cortex, the ventral pallium with the accessory olfactory amygdala. The rostral pallium, with its projections to the dorsal and ventral striatopallidum, resembles the mammalian frontal cortex.
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Connectivity and cytoarchitecture of telencephalic centers in the Fire-Bellied Toad Bombina orientalis.
Brain research bulletin, 2005Co-Authors: Sabine Mühlenbrock-lenter, Gerhard Roth, Wolfgang GrunwaldAbstract:In the Fire-Bellied Toad Bombina orientalis, the connectivity and cytoarchitecture of telencephalic structures were studied by intracellular, anterograde and retrograde biocytin labelling in order to elucidate the neuronal basis of fear conditioning and context learning in amphibians. Our findings suggest the existence of a central amygdala-bed nucleus of the stria terminalis complex in the caudal mid-ventral telencephalon, a vomeronasal amygdala in the caudolateral ventral telencephalon, an olfactory amygdala in the caudal pole of the telencephalon lateral of the vomeronasal amygdala, and a ventromedially situated "medial" amygdala, which is assumed to be functionally equivalent to the basolateral amygdala of mammals. A ventromedial cellular column forms a nucleus accumbens rostrally and continues caudally into a shell-like ventral pallidum. A lateral column constitutes a dorsal striatum proper rostrally, a dorsal pallidum caudally, and a mixed striato-pallidum at intermediate levels. We conclude that the caudal mediolateral complex consisting of an extended central, vomeronasal and olfactory amygdala of anurans represents the ancestral equivalent of the amygdaloid complex of tetrapods. During the evolution of the mammalian telencephalon, this complex apparently was shifted medially and involuted.
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Morphology and axonal projection pattern of neurons in the telencephalon of the fire‐bellied Toad Bombina orientalis: An anterograde, retrograde, and intracellular biocytin labeling study
The Journal of comparative neurology, 2004Co-Authors: Gerhard Roth, Sabine Mühlenbrock-lenter, Wolfgang Grunwald, Frederic LabergeAbstract:The connectivity and cytoarchitecture of telencephalic centers except dorsal and medial pallium were studied in the Fire-Bellied Toad Bombina orientalis by anterograde and retrograde biocytin labeling and intracellular biocytin injection (total of 148 intracellularly labeled neurons or neuron clusters). Our findings suggest the following telencephalic divisions: (1) a central amygdala–bed nucleus of the stria terminalis in the caudal midventral telencephalon, connected to visceral–autonomic centers; (2) a vomeronasal amygdala in the caudolateral ventral telencephalon receiving input from the accessory olfactory bulb and projecting mainly to the preoptic region/hypothalamus; (3) an olfactory amygdala in the caudal pole of the telencephalon lateral to the vomeronasal amygdala receiving input from the main olfactory bulb and projecting to the hypothalamus; (4) a medial amygdala receiving input from the anterior dorsal thalamus and projecting to the medial pallium, septum, and hypothalamus; (5) a ventromedial column formed by a nucleus accumbens and a ventral pallidum projecting to the central amygdala, hypothalamus, and posterior tubercle; (6) a lateral column constituting the dorsal striatum proper rostrally and the dorsal pallidum caudally, and a ventrolateral column constituting the ventral striatum. We conclude that the caudal mediolateral complex consisting of the extended central, vomeronasal, and olfactory amygdala of anurans represents the ancestral condition of the amygdaloid complex. During the evolution of the mammalian telencephalon this complex was shifted medially and involuted. The mammalian basolateral amygdala apparently is an evolutionary new structure, but the medial portion of the amygdalar complex of anurans reveals similarities in input and output with this structure and may serve similar functions. J. Comp. Neurol. 478:35–61, 2004. © 2004 Wiley-Liss, Inc.
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morphology axonal projection pattern and responses to optic nerve stimulation of thalamic neurons in the fire bellied Toad bombina orientalis
The Journal of Comparative Neurology, 2003Co-Authors: Gerhard Roth, Wolfgang Grunwald, Ursula DickeAbstract:Intracellular recording and biocytin labeling were carried out in the Fire-Bellied Toad Bombina orientalis to study the morphology and axonal projections of thalamic (TH) neurons and their responses to electrical optic nerve stimulation. Labeled neurons (n = 142) were divided into the following groups: TH1 neurons projecting to the dorsal striatum; TH2 neurons projecting to the amygdala, nucleus accumbens, and septal nuclei; TH3 neurons projecting to the medial or dorsal pallium; TH4 neurons with projections ascending to the dorsal striatum or ventral striatum/amygdala and descending to the optic tectum, tegmentum, and rostral medulla oblongata; TH5 neurons with projections to the tegmentum, rostral medulla oblongata, prectectum, or tectum; and TH6 neurons projecting to the hypothalamus. TH1 neurons are found in the central, TH2 neurons in the anterior and central, TH3 neurons in the anterior dorsal nucleus, and TH4 and TH5 neurons in the posterior dorsal or ventral nucleus. Neurons with descending projections arborize in restricted parts of retinal afferents; neurons with ascending projections do not substantially arborize within retinal afferents. At electrical optic nerve stimulation, neurons in the ventral thalamus respond with excitation at latencies of 10.8 msec; one-third of them follow repetitive stimulation and possibly are monosynaptically driven. Neurons in the dorsal thalamus respond mostly with inhibition at latencies of 42.3 msec and are polysynaptically driven. This corroborates the view that neurons in the dorsal thalamus projecting to the telencephalon receive no substantial direct retinal input and that the thalamopallial pathway of amphibians is not homologous to the mammalian retinogeniculocortical pathway. J. Comp. Neurol. 461:91–110, 2003. © 2003 Wiley-Liss, Inc.
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Morphology, axonal projection pattern, and responses to optic nerve stimulation of thalamic neurons in the Fire-Bellied Toad Bombina orientalis.
The Journal of comparative neurology, 2003Co-Authors: Gerhard Roth, Wolfgang Grunwald, Ursula DickeAbstract:Intracellular recording and biocytin labeling were carried out in the Fire-Bellied Toad Bombina orientalis to study the morphology and axonal projections of thalamic (TH) neurons and their responses to electrical optic nerve stimulation. Labeled neurons (n = 142) were divided into the following groups: TH1 neurons projecting to the dorsal striatum; TH2 neurons projecting to the amygdala, nucleus accumbens, and septal nuclei; TH3 neurons projecting to the medial or dorsal pallium; TH4 neurons with projections ascending to the dorsal striatum or ventral striatum/amygdala and descending to the optic tectum, tegmentum, and rostral medulla oblongata; TH5 neurons with projections to the tegmentum, rostral medulla oblongata, prectectum, or tectum; and TH6 neurons projecting to the hypothalamus. TH1 neurons are found in the central, TH2 neurons in the anterior and central, TH3 neurons in the anterior dorsal nucleus, and TH4 and TH5 neurons in the posterior dorsal or ventral nucleus. Neurons with descending projections arborize in restricted parts of retinal afferents; neurons with ascending projections do not substantially arborize within retinal afferents. At electrical optic nerve stimulation, neurons in the ventral thalamus respond with excitation at latencies of 10.8 msec; one-third of them follow repetitive stimulation and possibly are monosynaptically driven. Neurons in the dorsal thalamus respond mostly with inhibition at latencies of 42.3 msec and are polysynaptically driven. This corroborates the view that neurons in the dorsal thalamus projecting to the telencephalon receive no substantial direct retinal input and that the thalamopallial pathway of amphibians is not homologous to the mammalian retinogeniculocortical pathway.