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Loreta Medina - One of the best experts on this subject based on the ideXlab platform.
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A novel telencephalon-opto-hypothalamic morphogenetic domain coexpressing Foxg1 and Otp produces most of the glutamatergic neurons of the medial Extended Amygdala.
The Journal of comparative neurology, 2021Co-Authors: Lorena Morales, Antonio Abellán, Ester Desfilis, Beatriz Castro-robles, Loreta MedinaAbstract:Deficits in social cognition and behavior are a hallmark of many psychiatric disorders. The medial Extended Amygdala, including the medial Amygdala and the medial bed nucleus of the stria terminalis, is a key component of functional networks involved in sociality. However, this nuclear complex is highly heterogeneous and contains numerous GABAergic and glutamatergic neuron subpopulations. Deciphering the connections of different neurons is essential in order to understand how this structure regulates different aspects of sociality, and it is necessary to evaluate their differential implication in distinct mental disorders. Developmental studies in different vertebrates are offering new venues to understand neuronal diversity of the medial Extended Amygdala and are helping to establish a relation between the embryonic origin and molecular signature of distinct neurons with the functional subcircuits in which they are engaged. These studies have provided many details on the distinct GABAergic neurons of the medial Extended Amygdala, but information on the glutamatergic neurons is still scarce. Using an Otp-eGFP transgenic mouse and multiple fluorescent labeling, we show that most glutamatergic neurons of the medial Extended Amygdala originate in a distinct telencephalon-opto-hypothalamic embryonic domain (TOH), located at the transition between telencephalon and hypothalamus, which produces Otp-lineage neurons expressing the telencephalic marker Foxg1 but not Nkx2.1 during development. These glutamatergic cells include a subpopulation of projection neurons of the medial Amygdala, which activation has been previously shown to promote autistic-like behavior. Our data open new venues for studying the implication of this neuron subtype in neurodevelopmental disorders producing social deficits.
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A novel telencephalon-opto-hypothalamic morphogenetic domain produces most of the glutamatergic neurons of the medial Extended Amygdala
2020Co-Authors: Lorena Morales, Antonio Abellán, Ester Desfilis, Beatriz Castro-robles, Loreta MedinaAbstract:Abstract Deficits in social cognition and behavior are a hallmark of many psychiatric disorders. The medial Extended Amygdala, including the medial Amygdala and the medial bed nucleus of the stria terminalis, is a key component of functional networks involved in sociality. However, this nuclear complex is highly heterogeneous and contains numerous GABAergic and glutamatergic neuron subpopulations. Deciphering the connections of different neurons is essential in order to understand how this structure regulates different aspects of sociality, and it is necessary to evaluate their differential implication in distinct mental disorders. Developmental studies in different vertebrates are offering new venues to understand neuronal diversity of the medial Extended Amygdala, and are helping to establish a relation between the embryonic origin and molecular signature of distinct neurons with the functional subcircuits in which they are engaged. These studies have provided many details on the distinct GABAergic neurons of the medial Extended Amygdala, but information on the glutamatergic neurons is still scarce. Using an Otp-eGFP transgenic mouse and multiple fluorescent labeling, we show that most glutamatergic neurons of the medial Extended Amygdala originate in a novel telencephalo-opto-hypothalamic embryonic domain (TOH), located at the transition between telencephalon and hypothalamus, which produces Otp-lineage neurons expressing the telencephalic marker Foxg1 but not Nkx2.1 during development. These glutamatergic cells include a subpopulation of projection neurons of the medial Amygdala, which activation has been previously shown to promote autistic-like behavior. Our data open new venues for studying the implication of this neuron subtype in neurodevelopmental disorders producing social deficits.
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Genetic identification of the central nucleus and other components of the central Extended Amygdala in chicken during development.
Frontiers in neuroanatomy, 2014Co-Authors: Alba Vicario, Antonio Abellán, Ester Desfilis, Loreta MedinaAbstract:In mammals, the central Extended Amygdala shows a highly complex organization, and is essential for animal survival due to its implication in fear responses. However, many aspects of its evolution are still unknown, and this structure is especially poorly understood in birds. The aim of this study was to define the central Extended Amygdala in chicken, by means of a battery of region-specific transcription factors (Pax6, Islet1, Nkx2.1) and phenotypic markers that characterize these different subdivisions in mammals. Our results allowed the identification of at least six distinct subdivisions in the lateral part of the avian central Extended Amygdala: (1) capsular central subdivision; (2) a group of intercalated-like cell patches; (3) oval central nucleus; (4) peri-intrapeduncular (peri-INP) island field; (5) perioval zone; and (6) a rostral part of the subpallial Extended Amygdala. In addition, we identified three subdivisions of the laterodorsal bed nucleus of the stria terminalis (BSTLd) belonging to the medial region of the chicken central Extended Amygdala complex. Based on their genetic profile, cellular composition and apparent embryonic origin of the cells, we discuss the similarity of these different subdivisions of chicken with different parts of the mouse central Amygdala and surrounding cell masses, including the intercalated Amygdalar masses and the sublenticular part of the central Extended Amygdala. Most of the subdivisions include various subpopulations of cells that apparently originate in the dorsal striatal, ventral striatal, pallidal, and preoptic embryonic domains, reaching their final location by either radial or tangential migrations. Similarly to mammals, the central Amygdala and BSTLd of chicken project to the hypothalamus, and include different neurons expressing proenkephalin, corticotropin-releasing factor, somatostatin or tyrosine hydroxylase, which may be involved in the control of different aspects of fear/anxiety-related behavior.
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Genetic and Experimental Evidence Supports the Continuum of the Central Extended Amygdala and a Mutiple Embryonic Origin of Its Principal Neurons
The Journal of comparative neurology, 2011Co-Authors: Munisamy Bupesh, Antonio Abellán, Loreta MedinaAbstract:The central Extended Amygdala is the major output center for telencephalic control of ingestion, fear responses, stress, and anxiety. In spite of the abundant data supporting the similarity in neurochemistry, connections, and function along the Extended Amygdala, embryological support for this continuum is lacking. By using a combination of in vitro migration assays, in situ hybridization, and immunostaining, here we show that its major components, including central Amygdala and lateral bed nucleus of the stria terminalis (BST), are mosaics formed by different proportions of dorsal lateral ganglionic eminence (LGE)-, ventral LGE-, and medial ganglionic eminence (MGE)-derived principal neurons. The dorsal LGE produces Pax6-expressing neurons that primarily populate lateral parts of the central Extended Amygdala, including the capsular and part of lateral central Amygdala, but also produces a few cells for the lateral BST. Based on correlation with preproenkephalin, many of these cells are likely enkephalinergic. The ventral LGE produces Islet1-expressing neurons that populate primarily the central and medial parts of the central Amygdala but also produces numerous neurons for the lateral BST. Correlation with corticotropin-releasing factor suggests that these neurons express this neuropeptide. The MGE produces the majority of neurons of the lateral BST, but its ventrocaudal subdivision also produces an important subpopulation of projection neurons containing somatostatin for medial aspects of the central Amygdala. Thus, distinct principal neurons originate in different embryonic domains, but the same domains contribute neurons to most subdivisions of the central Extended Amygdala, which may explain the similarity in neurochemistry and connections along the corridor.
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Multiple telencephalic and extratelencephalic embryonic domains contribute neurons to the medial Extended Amygdala.
The Journal of comparative neurology, 2011Co-Authors: Munisamy Bupesh, Isabel Legaz, Antonio Abellán, Loreta MedinaAbstract:Dysfunctions in emotional control and social behavior are behind human neuropsychiatric disorders, some of which are associated with an alteration of Amygdalar development. The medial Extended Amygdala is a key telencephalic center for control of social behavior, but very little is known about its development. We used in vitro migration assays for analyzing the origin of the neurons of the medial Extended Amygdala in mouse embryos (E13.5-E16.5). We compared the migration assays with immunofluorescence/immunohistochemistry for calbindin and radial glial fibers and with mRNA expression of several genetic markers of distinct forebrain subdivisions. We provide experimental evidence for multiple embryonic origins of the principal neurons of the medial Extended Amygdala. In particular, we provide novel evidence indicating that a major part of the neurons derives from a caudoventral pallidal subdivision (previously called or included as part of the anterior peduncular area), forming a cell corridor with similar molecular features (expression of Lhx6 and calbindin), connectivity, and function, which relates to reproductive behavior. We also provide novel experimental evidence indicating that the ventral pallium produces some neurons for the medial Amygdala, which correlates with data from Lhx9 expression. Our results also confirm that some neurons of the medial Extended Amygdala originate in the preoptic area (our results indicate that these cells specifically originate in its commissural subdivision) and the supraoptoparaventricular domain of the hypothalamus. Our study helps to set up the foundations for a better understanding of medial Amygdalar control of behavior in normal and abnormal conditions.
George F. Alheid - One of the best experts on this subject based on the ideXlab platform.
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Extended Amygdala and basal forebrain
Annals of the New York Academy of Sciences, 2006Co-Authors: George F. AlheidAbstract:: The basal forebrain is a confluence of systems that are crucial to understanding some of the most important functions of the brain, including reward and punishment, learning and cognition, and feeding and reproduction. Basic to understanding this broad spectrum of behavior is untangling the interwoven functional systems in basal forebrain. This has been grounded by the appreciation that the major nearby structures, that is, Amygdala and basal ganglia, provide a context for interpreting basal forebrain areas that are best viewed as extensions of either of these larger regions. The components of basal forebrain, the ventral striatopallidal system and the medial and central divisions of Extended Amygdala, are subcortical relays for information garnered from brain stem, thalamus, and cortical areas. With respect to the classically defined Amygdala of the temporal lobe, the lateral-basolateral complex, and the superficial amygdaloid nuclei may tentatively be viewed as specialized cortical regions. Their output targets both the striatopallidal complex and the Extended Amygdala, with some of the most massive basal forebrain efferents originating in the basolateral amygdaloid complex. The subcortical projections of the basolateral nucleus, at least in the rat, appear to be dichotomous, with anterior (or magnocellular) portions of the nucleus preferentially targeting striatum and ventral striatum (including the core of the nucleus accumbens), while the posterior (small-celled) portions of the basolateral nucleus target the Extended Amygdala as well as the shell of the nucleus accumbens. This divergence represents a particular opportunity for behavioral neuroscientists analyzing basal forebrain functions. Studies exploiting the dual subcortical projection of basolateral Amygdala indicate distinct functional roles for striatum versus Extended Amygdala. These reinforce the identification of Extended Amygdala as a functional-anatomical entity distinct from the striatopallidal system.
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Compartmentation of alpha 1 and alpha 2 GABAA receptor subunits within rat Extended Amygdala: implications for benzodiazepine action
Brain research, 2003Co-Authors: Walter A. Kaufmann, George F. Alheid, C. Humpel, Josef MarksteinerAbstract:Abstract The Extended Amygdala, a morphological and functional entity within the basal forebrain, is a neuronal substrate for emotional states like fear and anxiety. Anxiety disorders are commonly treated by benzodiazepines that mediate their action via GABA A receptors. The binding properties and action of benzodiazepines depend on the α-subunit profile of the hetero-pentameric receptors: whereas the α1 subunit is associated with benzodiazepine type I pharmacology and reportedly mediates sedative as well as amnesic actions of benzodiazepines, the α2 subunit confers benzodiazepine type II pharmacology and mediates the anxiolytic actions of benzodiazepines. We determined the localization of α1 and α2 subunits within the Extended Amygdala, identified by secretoneurin immunostaining, to define the morphological substrates for the diverse benzodiazepine actions. A moderate expression of the α1 subunit could be detected in compartments of the medial subdivision and a strong expression of the α2 subunit throughout the central subdivision. It is concluded that the α1 and α2 subunits are differentially expressed within the Extended Amygdala, indicating that this structure is compartmentalized with respect to function and benzodiazepine action.
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Supracapsular bed nucleus of the stria terminalis contains central and medial Extended Amygdala elements: evidence from anterograde and retrograde tracing experiments in the rat.
The Journal of comparative neurology, 2000Co-Authors: Sara J. Shammah-lagnado, Carlos A. Beltramino, Lennart Heimer, Alexander J. Mcdonald, Richard R. Miselis, Ming Yang, Jose De Olmos, George F. AlheidAbstract:Neurons that accompany the stria terminalis as it loops over the internal capsule have been termed collectively the supracapsular bed nucleus of the stria terminalis (BSTS). They form two cell columns, a lateral column and a considerably smaller medial column. The lateral column merges rostrally with the lateral bed nucleus of the stria terminalis and caudally with the central amygdaloid nucleus (central Extended Amygdala components). The medial column is continuous with the medial bed nucleus of the stria terminalis and the medial amygdaloid nucleus (medial Extended Amygdala districts). The connections of the BSTS were investigated in the rat by placing injections of Phaseolus vulgaris-leucoagglutinin (PHA-L) or retrograde tracers in different parts of the Extended Amygdala or in structures related to the Extended Amygdala. BSTS inputs and outputs were identified, respectively, by the presence of varicose fibers and retrogradely labeled neurons within the stria terminalis. The results suggest that the medial-to-lateral compartmentalization of BSTS neurons reflects their close alliance with the medial and central divisions of the Extended Amygdala. The medial BSTS contains primarily elements that correspond to the posterodorsal part of the medial amygdaloid nucleus and the medial column of the posterior division of the medial bed nucleus of the stria terminalis, and the lateral BSTS contains elements that correspond to the medial and lateral parts of the central amygdaloid nucleus and lateral bed nucleus of the stria terminalis. These results add strong support to the concept of the Extended Amygdala as a ring-like macrostructure around the internal capsule, and they are of theoretical interest for the understanding of the organization of the basal forebrain. J. Comp. Neurol. 422:533–555, 2000. © 2000 Wiley-Liss, Inc.
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supracapsular bed nucleus of the stria terminalis contains central and medial Extended Amygdala elements evidence from anterograde and retrograde tracing experiments in the rat
The Journal of Comparative Neurology, 2000Co-Authors: Sara J Shammahlagnado, Carlos A. Beltramino, Lennart Heimer, Alexander J. Mcdonald, Richard R. Miselis, Ming Yang, Jose De Olmos, George F. AlheidAbstract:Neurons that accompany the stria terminalis as it loops over the internal capsule have been termed collectively the supracapsular bed nucleus of the stria terminalis (BSTS). They form two cell columns, a lateral column and a considerably smaller medial column. The lateral column merges rostrally with the lateral bed nucleus of the stria terminalis and caudally with the central amygdaloid nucleus (central Extended Amygdala components). The medial column is continuous with the medial bed nucleus of the stria terminalis and the medial amygdaloid nucleus (medial Extended Amygdala districts). The connections of the BSTS were investigated in the rat by placing injections of Phaseolus vulgaris-leucoagglutinin (PHA-L) or retrograde tracers in different parts of the Extended Amygdala or in structures related to the Extended Amygdala. BSTS inputs and outputs were identified, respectively, by the presence of varicose fibers and retrogradely labeled neurons within the stria terminalis. The results suggest that the medial-to-lateral compartmentalization of BSTS neurons reflects their close alliance with the medial and central divisions of the Extended Amygdala. The medial BSTS contains primarily elements that correspond to the posterodorsal part of the medial amygdaloid nucleus and the medial column of the posterior division of the medial bed nucleus of the stria terminalis, and the lateral BSTS contains elements that correspond to the medial and lateral parts of the central amygdaloid nucleus and lateral bed nucleus of the stria terminalis. These results add strong support to the concept of the Extended Amygdala as a ring-like macrostructure around the internal capsule, and they are of theoretical interest for the understanding of the organization of the basal forebrain.
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Transition Areas of the Striatopallidal System with the Extended Amygdala in the Rat and Primate: Observations from Histochemistry and Experiments with Mono- and Transsynaptic Tracer
Advances in Behavioral Biology, 1994Co-Authors: George F. Alheid, Carlos A. Beltramino, Richard R. Miselis, Alex Braun, Chantal François, Jose De OlmosAbstract:In several papers we have extensively reviewed the concepts of the ventral striatopallidal system and the Extended Amygdala (de Olmos et al., 1985; Heimer et al., 1985; Alheid and Heimer, 1988; Alheid et al., 1990; Heimer and Alheid, 1991; Heimer et al., 1991a, 1993), and these topics are only briefly recapitulated here. In some of these (e.g. Alheid and Heimer, 1988; Heimer and Alheid, 1991; Heimer et al., 1993) we have pointed out areas where these two structures are difficult to distinguish; these are the problem areas that we wish to confront in this chapter. In some instances, it is clear that the Extended Amygdala occupies portions of the forebrain normally considered part of the basal ganglia and more speculatively, we believe that some unusual features in other areas of the basal ganglia might reflect some ectopic elements of the Extended Amygdala.
Pierre Veinante - One of the best experts on this subject based on the ideXlab platform.
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c-Fos and peptide immunoreactivities in the central Extended Amygdala of morphine-dependent rats after naloxone-precipitated withdrawal.
The European journal of neuroscience, 2003Co-Authors: Pierre Veinante, Marie-elisabeth Stoeckel, François Lasbennes, Marie-josé Freund-mercierAbstract:The central Extended Amygdala, a forebrain macrostructure, may represent a common substrate for acute drug reward and the dysphoric effects of drug withdrawal. To test its involvement during opiate withdrawal, we studied the distribution of c-Fos immunoreactive neurons, in relation to their neuropeptide content, in brain sections from morphine-dependent or naive rats, killed 90 min after naloxone or saline intraperitoneal injection. Naloxone treatment in naive rats induced a slight increase in c-Fos immunoreactivity in the central amygdaloid nucleus, the lateral bed nucleus of the stria terminalis and the interstitial nucleus of the posterior limb of the anterior commissure. In morphine-dependent rats, naloxone injection significantly increased the number of c-Fos-positive neurons in these structures as well as in the majority of the other central Extended Amygdala components. Double immunocytochemistry was used to determine the neurochemical nature of c-Fos-positive neurons in the central Extended Amygdala. Corticotropin-releasing factor- and methionine-enkephakin-immunoreactive neurons displayed c-Fos immunoreactivity in naive rats after naloxone injection, whereas only enkephalinergic neurons were found to be c-Fos positive in morphine-dependent rats after naloxone injection. The possible involvement of the corticotropin-releasing factor system during withdrawal is discussed. These results suggest that the whole central Extended Amygdala is activated during opiate withdrawal, with a lateral to medial decreasing gradient, and emphasize the role of peptidergic systems in this morphofunctional continuum.
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Intrinsic and extrinsic connections of the rat central Extended Amygdala: an in vivo electrophysiological study of the central amygdaloid nucleus
Brain research, 1998Co-Authors: Pierre Veinante, Marie-josé Freund-mercierAbstract:Anatomical studies have shown that the central amygdaloid nucleus (CeA) is reciprocally connected with the lateral bed nucleus of the stria terminalis (BSTL), both structures being major components of the central Extended Amygdala. The CeA also receives projections from the insular cortex (InsCx) and the paraventricular thalamic nucleus (PVT). Extracellular unit activity was recorded from neurons in the lateral CeA (CeL) in urethane anaesthetized rats and their responses were studied after electrical stimulation of the BSTL, InsCx and PVT. The spontaneous activity of CeL neurons was low (1.69 spikes/s) and 40% of recorded cells were silent. The iontophoretic application of the GABAA antagonist, bicuculline, increased the firing rate of 20% of neurons. The BSTL stimulation induced an antidromic response in 33% of the tested cells. Orthodromic responses were obtained from 83% (BSTL stimulation), 70% (InsCx stimulation) and 85% (PVT stimulation) of tested cells, some of which responded to both BSTL and InsCx or PVT stimulations. Orthodromic responses mostly consisted in 1-3 orthodromic spikes followed by an inhibition. During iontophoretic application of bicuculline, stimulation induced additional short latency orthodromic spikes, even in cells that were previously unresponsive. However, the duration of the inhibition was never reduced. These results indicate that GABAergic neurotransmission may play a dominant role in both spontaneous and evoked electrical activities in the CeL, probably mediated by local circuit cells involved in a feed-forward inhibition. This organization, along with the reciprocal connections between the CeL and the BSTL, is considered in the context of the Extended Amygdala.
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GABA- and peptide-immunoreactivities co-localize in the rat central Extended Amygdala.
Neuroreport, 1997Co-Authors: Pierre Veinante, Marie-elisabeth Stoeckel, Marie-josé Freund-mercierAbstract:The central amygdaloid nucleus and the lateral bed nucleus of the stria terminalis are two similar telencephalic structures belonging to the central Extended Amygdala. These regions contain numerous peptidergic and GABAergic neurones which maintain the neurones projecting to the brain stem under tight intrinsic control. Using immunocytochemistry in colchicine-treated rats, we showed that, in the lateral subdivision of the central amygdaloid nucleus and in the dorsal part of the lateral bed nucleus of the stria terminalis, a population of GABAergic neurones is able to co-synthesize either corticotropin-releasing factor or methionine-enkephalin, but never both peptides. These results suggest that, in the GABAergic intrinsic circuits of the central Extended Amygdala, co-liberated peptides can have a modulatory role on GABAergic actions.
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distribution of oxytocin and vasopressin binding sites in the rat Extended Amygdala a histoautoradiographic study
The Journal of Comparative Neurology, 1997Co-Authors: Pierre Veinante, Mariejose FreundmercierAbstract:Radioligand receptor autoradiography has shown that oxytocin- and vasopressin-binding sites exist in numerous rat brain regions, among which the Amygdala and the bed nucleus of the stria terminalis (BST) are especially prominent. However, these descriptions did not take into account the numerous subdivisions of the Amygdala and the BST. Thus, we have reinvestigated the distribution of these sites in the rat Extended Amygdala, which is formed by a continuum of structures stretching from the BST to the centromedial Amygdala, including parts of the accumbens nucleus, substantia innominata, and transition areas between the Amygdala and the striatum. For this purpose, histoautoradiography was used to detect binding sites at the cellular level, and anatomical boundaries were defined on the basis of acetylcholinesterase histochemistry and tyrosine-hydroxylase immunohistochemistry. Oxytocin- and vasopressin-binding sites were detected in well-defined subdivisions of both medial and central parts of the Extended Amygdala, but they almost never coexisted in the same region. Compared with previously reported distributions, our reinvestigation describes novel oxytocin- and vasopressin-binding sites in the lateral and supracapsular BST, in the sublenticular Extended Amygdala, in the interstitial nucleus of the posterior limb of the anterior commissure, in the marginal zone, in the central amygdaloid nucleus, and in the anterior amygdaloid area. These results indicate that oxytocin- and vasopressin-binding sites represent an important feature of the Extended Amygdala and may participate in the large variety of functions that characterize this area, including reproductive and ingestive behaviors, conditioned fear and autonomic regulation. J. Comp. Neurol. 383:305-325, 1997. © 1997 Wiley-Liss, Inc.
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distribution of oxytocin and vasopressin binding sites in the rat Extended Amygdala a histoautoradiographic study
The Journal of Comparative Neurology, 1997Co-Authors: Pierre Veinante, Mariejose FreundmercierAbstract:Radioligand receptor autoradiography has shown that oxytocin- and vasopressin-binding sites exist in numerous rat brain regions, among which the Amygdala and the bed nucleus of the stria terminalis (BST) are especially prominent. However, these descriptions did not take into account the numerous subdivisions of the Amygdala and the BST. Thus, we have reinvestigated the distribution of these sites in the rat Extended Amygdala, which is formed by a continuum of structures stretching from the BST to the centromedial Amygdala, including parts of the accumbens nucleus, substantia innominata, and transition areas between the Amygdala and the striatum. For this purpose, histoautoradiography was used to detect binding sites at the cellular level, and anatomical boundaries were defined on the basis of acetylcholinesterase histochemistry and tyrosine-hydroxylase immunohistochemistry. Oxytocin- and vasopressin-binding sites were detected in well-defined subdivisions of both medial and central parts of the Extended Amygdala, but they almost never coexisted in the same region. Compared with previously reported distributions, our reinvestigation describes novel oxytocin- and vasopressin-binding sites in the lateral and supracapsular BST, in the sublenticular Extended Amygdala, in the interstitial nucleus of the posterior limb of the anterior commissure, in the marginal zone, in the central amygdaloid nucleus, and in the anterior amygdaloid area. These results indicate that oxytocin- and vasopressin-binding sites represent an important feature of the Extended Amygdala and may participate in the large variety of functions that characterize this area, including reproductive and ingestive behaviors, conditioned fear and autonomic regulation.
Daniel S. Zahm - One of the best experts on this subject based on the ideXlab platform.
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synaptologic and fine structural features distinguishing a subset of basal forebrain cholinergic neurons embedded in the dense intrinsic fiber network of the caudal Extended Amygdala
The Journal of Comparative Neurology, 2006Co-Authors: Louise D Loopuijt, Daniel S. ZahmAbstract:Cholinergic basal forebrain neurons confined within the intrinsic connections of the Extended Amygdala in the caudal sublenticular region and anterior amygdaloid area (cSLR/AAA) differ from other basal forebrain cholinergic neurons in several morphological and neurochemical respects. These cSLR/AAA cholinergic neurons have been subjected to additional investigations described in this report. First, fibers traced anterogradely following injections of Phaseolus vulgaris-leucoagglutinin in the central amygdaloid nucleus were shown to contact cSLR/AAA cholinergic neurons and dendrites. Second, these neurons were shown to be contacted by numerous GABAergic boutons with symmetric synaptic specializations. Third, the numbers of synaptic densities of morphologically characterized symmetric contacts on the somata and proximal dendrites of cSLR/AAA cholinergic neurons were shown to significantly exceed those of extra-cSLR/AAA cholinergic neurons. Fourth, fine structural features distinguishing cSLR/AAA cholinergic neurons from other basal forebrain cholinergic neurons were revealed. Specifically, cSLR/AAA cholinergic neurons have less abundant cytoplasm and a less well-organized system of rough endoplasmic reticulum than their counterparts in other parts of the basal forebrain. Thus, morphologically and neurochemically distinct cSLR/AAA cholinergic neurons exhibit robust proximal inhibitory inputs, of which a significant number originate in the Extended Amygdala, while cholinergic neurons outside this region lack a substrate for strong proximal inhibitory input. The implications of these findings for interaction of fear, anxiety, and attention are considered. J. Comp. Neurol. 498:93–111, 2006. © 2006 Wiley-Liss, Inc.
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Specificity in the Projections of Prefrontal and Insular Cortex to Ventral Striatopallidum and the Extended Amygdala
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2005Co-Authors: Sheila M. Reynolds, Daniel S. ZahmAbstract:The basal forebrain functional-anatomical macrosystems, ventral striatopallidum, and Extended Amygdala are innervated by substantially coextensive distributions of neurons in the prefrontal and insular cortex. This suggests two alternative organizational schemes: convergent, in which a given cortical area projects exclusively to only one of these macrosystems and divergent, in which a given cortical area innervates both forebrain macrosystems. To examine the underlying organization and possibly discriminate between these alternatives, rats were injected with two retrograde tracers in different parts of ventral striatopallidum or Extended Amygdala (homotypic injection pairs) or with one tracer in each macrosystem (heterotypic). The prefrontal and insular cortex was evaluated microscopically for overlap of retrograde labeling and double labeling of neurons. Homotypic injection pairs in the ventral striatum and Extended Amygdala produced extensive overlap of retrogradely labeled neurons and significant double labeling, suggesting that cortical projections spread broadly within macrosystems. In contrast, heterotypic injection pairs produced significant overlap of retrograde labeling but negligible double labeling, indicating that ventral striatopallidum and Extended Amygdala receive inputs from separate sets of prefronto- and insular cortical neurons. The caudomedial shell of the nucleus accumbens, a supposed "transition" zone between striatopallidum and Extended Amygdala, had Extended Amygdala-like afferents but produced few double-labeled neurons and these only when paired with ventral striatopallidum. The data suggest that a modular organization of the basal forebrain, with postulated independent information processing by the ventral striatopallidal and Extended Amygdala macrosystems, is reflected in a corresponding segregation of output neurons in the prefrontal and insular cortices.
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Discrimination of striatopallidum and Extended Amygdala in the rat: a role for parvalbumin immunoreactive neurons?
Brain Research, 2003Co-Authors: Daniel S. Zahm, S. Grosu, Joi C. Irving, Evelyn A. WilliamsAbstract:Synaptic effects of parvalbumin-immunoreactive (-ir) interneurons (PVs) upon medium spiny neurons may be essential to neural processing in the striatum and, in effect, may serve as an additional feature distinguishing striatum from Extended Amygdala. The present immunohistochemical study in the rat was done to evaluate the distributions of PVs in the striatum and Extended Amygdala. Numerous PVs occupy all structures currently regarded as having a striatal composition, including the caudate-putamen, nucleus accumbens, and olfactory tubercle, as well as structures that receive outputs from these, including the globus pallidus, ventral pallidum, entopeduncular nucleus and substantia nigra reticulata. The morphologies of striatal PVs and their distribution were similar to what has been previously reported. In addition, we found that the density of larger neostriatal PVs with extensive and densely immunoreactive dendritic and local axonal arbors is greatest laterally, particularly in striatal districts with slight calbindin-ir, including the striatal patch compartment. In contrast to the situation in striatum, few PVs were observed in the central and medial divisions of the Extended Amygdala, including the bed nucleus of stria terminalis, interstitial nucleus of the posterior limb of the anterior commissure and central and medial nuclei of the Amygdala, or in mesopontine, peribrachial and medullary structures that receive Extended Amygdala output. The paucity of PVs may be a characteristic feature distinguishing Extended Amygdala and its projection areas from striatopallidum, as well as the general character of neural processing that occurs in each.
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The caudal sublenticular region/anterior amygdaloid area is the only part of the rat forebrain and mesopontine tegmentum occupied by magnocellular cholinergic neurons that receives outputs from the central division of Extended Amygdala
Brain research, 2002Co-Authors: Myriam Gastard, Sarah L. Jensen, John R. Martin, Evelyn A. Williams, Daniel S. ZahmAbstract:Ascending cholinergic projections and the central nucleus of the Amygdala (CeA) have both been implicated in attentional and orienting mechanisms leading to adaptive behavioral responses. In view of this, the present study was carried out to identify relevant neuroanatomical relationships in the form of projections from the CeA and a related structure, the dorsolateral divison of the bed nucleus of the stria terminalis (dlBST), to parts of the basal forebrain and mesopontine tegmentum that contain magnocellular cholinergic neurons. The CeA and dlBST are components of the 'central division of Extended Amygdala'. Following injections of the anterogradely transported compounds, Phaseolus vulgaris-leucoagglutinin or biotinylated dextran amine, into the CeA or dlBST, sections were processed with immunohistochemical reagents to localize the anterograde tracer and choline acetyltransferase (ChAT). The trajectories of efferent projections from CeA and dlBST were qualitatively similar. Few ChAT-immunoreactive (ir) neurons were present within the Extended Amygdala or regions containing the dense terminations of its efferent projections, with the striking exception of the caudal sublenticular/anterior amygdaloid region. The ChAT-ir neurons there, however, were significantly smaller and weakly ChAT-ir as compared to those located outside of the dense Extended amygdaloid terminations. In the mesopontine tegmentum, the robust downstream projection from the Extended Amygdala was centered medial to ChAT-ir neurons of the pedunculopontine tegmental nucleus. The differentiated character of the relationships between Extended Amygdala and forebrain and mesopontine districts containing ChAT-ir neurons that give rise to ascending projections may have significant implications for the control of cortical and diencephalic acetylcholine release and accompanying effects on attention, vigilance and locomotor activation.
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the caudal sublenticular region anterior amygdaloid area is the only part of the rat forebrain and mesopontine tegmentum occupied by magnocellular cholinergic neurons that receives outputs from the central division of Extended Amygdala
Brain Research, 2002Co-Authors: Myriam Gastard, Sarah L. Jensen, John R. Martin, Evelyn A. Williams, Daniel S. ZahmAbstract:Ascending cholinergic projections and the central nucleus of the Amygdala (CeA) have both been implicated in attentional and orienting mechanisms leading to adaptive behavioral responses. In view of this, the present study was carried out to identify relevant neuroanatomical relationships in the form of projections from the CeA and a related structure, the dorsolateral divison of the bed nucleus of the stria terminalis (dlBST), to parts of the basal forebrain and mesopontine tegmentum that contain magnocellular cholinergic neurons. The CeA and dlBST are components of the 'central division of Extended Amygdala'. Following injections of the anterogradely transported compounds, Phaseolus vulgaris-leucoagglutinin or biotinylated dextran amine, into the CeA or dlBST, sections were processed with immunohistochemical reagents to localize the anterograde tracer and choline acetyltransferase (ChAT). The trajectories of efferent projections from CeA and dlBST were qualitatively similar. Few ChAT-immunoreactive (ir) neurons were present within the Extended Amygdala or regions containing the dense terminations of its efferent projections, with the striking exception of the caudal sublenticular/anterior amygdaloid region. The ChAT-ir neurons there, however, were significantly smaller and weakly ChAT-ir as compared to those located outside of the dense Extended amygdaloid terminations. In the mesopontine tegmentum, the robust downstream projection from the Extended Amygdala was centered medial to ChAT-ir neurons of the pedunculopontine tegmental nucleus. The differentiated character of the relationships between Extended Amygdala and forebrain and mesopontine districts containing ChAT-ir neurons that give rise to ascending projections may have significant implications for the control of cortical and diencephalic acetylcholine release and accompanying effects on attention, vigilance and locomotor activation.
Mariejose Freundmercier - One of the best experts on this subject based on the ideXlab platform.
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distribution of oxytocin and vasopressin binding sites in the rat Extended Amygdala a histoautoradiographic study
The Journal of Comparative Neurology, 1997Co-Authors: Pierre Veinante, Mariejose FreundmercierAbstract:Radioligand receptor autoradiography has shown that oxytocin- and vasopressin-binding sites exist in numerous rat brain regions, among which the Amygdala and the bed nucleus of the stria terminalis (BST) are especially prominent. However, these descriptions did not take into account the numerous subdivisions of the Amygdala and the BST. Thus, we have reinvestigated the distribution of these sites in the rat Extended Amygdala, which is formed by a continuum of structures stretching from the BST to the centromedial Amygdala, including parts of the accumbens nucleus, substantia innominata, and transition areas between the Amygdala and the striatum. For this purpose, histoautoradiography was used to detect binding sites at the cellular level, and anatomical boundaries were defined on the basis of acetylcholinesterase histochemistry and tyrosine-hydroxylase immunohistochemistry. Oxytocin- and vasopressin-binding sites were detected in well-defined subdivisions of both medial and central parts of the Extended Amygdala, but they almost never coexisted in the same region. Compared with previously reported distributions, our reinvestigation describes novel oxytocin- and vasopressin-binding sites in the lateral and supracapsular BST, in the sublenticular Extended Amygdala, in the interstitial nucleus of the posterior limb of the anterior commissure, in the marginal zone, in the central amygdaloid nucleus, and in the anterior amygdaloid area. These results indicate that oxytocin- and vasopressin-binding sites represent an important feature of the Extended Amygdala and may participate in the large variety of functions that characterize this area, including reproductive and ingestive behaviors, conditioned fear and autonomic regulation. J. Comp. Neurol. 383:305-325, 1997. © 1997 Wiley-Liss, Inc.
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distribution of oxytocin and vasopressin binding sites in the rat Extended Amygdala a histoautoradiographic study
The Journal of Comparative Neurology, 1997Co-Authors: Pierre Veinante, Mariejose FreundmercierAbstract:Radioligand receptor autoradiography has shown that oxytocin- and vasopressin-binding sites exist in numerous rat brain regions, among which the Amygdala and the bed nucleus of the stria terminalis (BST) are especially prominent. However, these descriptions did not take into account the numerous subdivisions of the Amygdala and the BST. Thus, we have reinvestigated the distribution of these sites in the rat Extended Amygdala, which is formed by a continuum of structures stretching from the BST to the centromedial Amygdala, including parts of the accumbens nucleus, substantia innominata, and transition areas between the Amygdala and the striatum. For this purpose, histoautoradiography was used to detect binding sites at the cellular level, and anatomical boundaries were defined on the basis of acetylcholinesterase histochemistry and tyrosine-hydroxylase immunohistochemistry. Oxytocin- and vasopressin-binding sites were detected in well-defined subdivisions of both medial and central parts of the Extended Amygdala, but they almost never coexisted in the same region. Compared with previously reported distributions, our reinvestigation describes novel oxytocin- and vasopressin-binding sites in the lateral and supracapsular BST, in the sublenticular Extended Amygdala, in the interstitial nucleus of the posterior limb of the anterior commissure, in the marginal zone, in the central amygdaloid nucleus, and in the anterior amygdaloid area. These results indicate that oxytocin- and vasopressin-binding sites represent an important feature of the Extended Amygdala and may participate in the large variety of functions that characterize this area, including reproductive and ingestive behaviors, conditioned fear and autonomic regulation.
