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E H Peterson - One of the best experts on this subject based on the ideXlab platform.
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functional architecture of vestibular primary afferents from the posterior semicircular canal of a turtle Pseudemys trachemys scripta elegans
The Journal of Comparative Neurology, 1994Co-Authors: Alan M Brichta, E H PetersonAbstract:Physiological studies inmany vertebrates indicate that vestibular primary afferents are not a homogeneous population. Such date raise the question of what structural mechanisms underlie these physiological differeneces and what functional role is played by afferents of each type. We have begun to answer these questions by characterizing the architecture of 110 afferents innervating the posterior canal of Pseudemys scripta. We emphasize their spatial organization because experimental evidence suggests that afferent physiological properties exhibit significant spatial heterogeneity. The sensory surface of the posterior canal comprises paired, triangular hemicristae, which are innervated by two afferent types. Bouton afferents (66% of total afferents) are found over the entire sensory surface. They differ significantly in the shape and size of their collecting areas, number of boutons, soma size, and axon diameter; this morphological variation is systematically related to the afferent's spatial postion. In addition, multivariate analyses suggest that bouton afferents may comprise two subtypes: α afferents have delicate processes and are found throughout the crista; β afferents are more robust and are concentrated preferentially toward the canal center. Calyx-bearing afferents comprise two morphological subtypes: dimorphs (13% of total afferents) bear calyceal and bouton endings; calyceal afferents (21%) bear calyceal endings only. Both types occur exclusively in an elliptical region near the center of each hemicrista; their morphology varies with radial distance from the center of this elliptical region. Our data provide evidence that in Pseudemys:(1) the classical vestibular afferents types (bouton, calyx, dimorph) are structurally heterogeneous, and (2) their spatial sampling characteristic are highly structured and distinctive for each type. These spatial patterns may shed light on regional differences in physiological profiles of vestibular afferents, and they raise questions about the role of this spatial heterogeneity in signaling head movement. © 1994 Wiley-Liss, Inc.
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functional architecture of vestibular primary afferents from the posterior semicircular canal of a turtle Pseudemys trachemys scripta elegans
The Journal of Comparative Neurology, 1994Co-Authors: Alan M Brichta, E H PetersonAbstract:Physiological studies in many vertebrates indicate that vestibular primary afferents are not a homogeneous population. Such data raise the question of what structural mechanisms underlie these physiological differences and what functional role is played by afferents of each type. We have begun to answer these questions by characterizing the architecture of 110 afferents innervating the posterior canal of Pseudemys scripta. We emphasize their spatial organization because experimental evidence suggests that afferent physiological properties exhibit significant spatial heterogeneity. The sensory surface of the posterior canal comprises paired, triangular hemicristae, which are innervated by two afferent types. Bouton afferents (66% of total afferents) are found over the entire sensory surface. They differ significantly in the shape and size of their collecting areas, number of boutons, soma size, and axon diameter; this morphological variation is systematically related to the afferent's spatial position. In addition, multivariate analyses suggest that bouton afferents may comprise two subtypes: alpha afferents have delicate processes and are found throughout the crista; beta afferents are more robust and are concentrated preferentially toward the canal center. Calyx-bearing afferents comprise two morphological subtypes: dimorphs (13% of total afferents) bear calyceal and bouton endings; calyceal afferents (21%) bear calyceal endings only. Both types occur exclusively in an elliptical region near the center of each hemicrista; their morphology varies with radial distance from the center of this elliptical region. Our data provide evidence that in Pseudemys: (1) the classical vestibular afferent types (bouton, calyx, dimorph) are structurally heterogeneous, and (2) their spatial sampling characteristics are highly structured and distinctive for each type. These spatial patterns may shed light on regional differences in physiological profiles of vestibular afferents, and they raise questions about the role of this spatial heterogeneity in signaling head movement.
Gordon M Burghardt - One of the best experts on this subject based on the ideXlab platform.
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long term retention of visual tasks by two species of emydid turtles Pseudemys nelsoni and trachemys scripta
Journal of Comparative Psychology, 2012Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:Long-lived species are expected to have long-term memory capabilities. In this study we tested nine Florida Red-bellied Cooters (Pseudemys nelsoni) on their retention for both a procedural food acquisition task and visual discrimination task learned in a previous experiment. The turtles were tested and retrained after two months, after another 7.5 months, and finally after 36 months of no interaction with the test apparatus during the intervening periods. Turtles retained memory for the choice task and needed little retraining throughout. Furthermore, in a different visual discrimination task, both P. nelsoni and Trachemys scripta turtles showed 100% retention after 3.5 months of no testing. Odor-controlled tests confirmed that turtles were using visual cues to solve the task. Thus, in a laboratory context turtles demonstrate long-term memory of visual discrimination tasks, which relates to apparent abilities in natural environments.
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turtles Pseudemys nelsoni learn about visual cues indicating food from experienced turtles
Journal of Comparative Psychology, 2011Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:We investigated whether turtles (Pseudemys nelsoni) could learn about a visual object cue to obtain food reinforcement by observing conspecifics that had learned the task. This study was designed with a three part task which, if completed by the observer turtles, would provide evidence of their abilities to learn from other turtles using stimulus enhancement, goal emulation, or copying. All four P. nelsoni turtles tested after observation of a trained demonstrator, whom they had direct access to during the demonstrator training trials, learned not only to follow another turtle to the stimulus indicating food, but also, in the absence of the demonstrator, to approach the correct stimulus regardless of spatial position. Therefore, all four P. nelsoni turtles tested showed evidence of stimulus enhancement learning. This is the first experimental study of social learning in any aquatic reptile demonstrating that they have the ability to learn from conspecifics.
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training and long term memory of a novel food acquisition task in a turtle Pseudemys nelsoni
Behavioural Processes, 2007Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:We developed a shaping procedure for training Florida red-bellied cooters, Pseudemys nelsoni, to dislodge clear plastic bottles to obtain food pellets. The animals were then trained in a 2-choice problem to choose only the bottle containing pellets. All nine turtles learned the task of knocking over bottles for food. For the discrimination task, turtles chose the correct bottle 71% on average. After 2 months (82-84 days), and again after another 7.5 months (228 days) of no interaction with the bottles, turtles were retested and many retained both the response and the discrimination (mean success rates 77-81%), with significant savings in retraining all turtles. The turtles showed two basic response strategies, which changed across time for some individuals. This study demonstrates that turtles can learn and retain a novel skill in a laboratory context.
Karen M Davis - One of the best experts on this subject based on the ideXlab platform.
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long term retention of visual tasks by two species of emydid turtles Pseudemys nelsoni and trachemys scripta
Journal of Comparative Psychology, 2012Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:Long-lived species are expected to have long-term memory capabilities. In this study we tested nine Florida Red-bellied Cooters (Pseudemys nelsoni) on their retention for both a procedural food acquisition task and visual discrimination task learned in a previous experiment. The turtles were tested and retrained after two months, after another 7.5 months, and finally after 36 months of no interaction with the test apparatus during the intervening periods. Turtles retained memory for the choice task and needed little retraining throughout. Furthermore, in a different visual discrimination task, both P. nelsoni and Trachemys scripta turtles showed 100% retention after 3.5 months of no testing. Odor-controlled tests confirmed that turtles were using visual cues to solve the task. Thus, in a laboratory context turtles demonstrate long-term memory of visual discrimination tasks, which relates to apparent abilities in natural environments.
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turtles Pseudemys nelsoni learn about visual cues indicating food from experienced turtles
Journal of Comparative Psychology, 2011Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:We investigated whether turtles (Pseudemys nelsoni) could learn about a visual object cue to obtain food reinforcement by observing conspecifics that had learned the task. This study was designed with a three part task which, if completed by the observer turtles, would provide evidence of their abilities to learn from other turtles using stimulus enhancement, goal emulation, or copying. All four P. nelsoni turtles tested after observation of a trained demonstrator, whom they had direct access to during the demonstrator training trials, learned not only to follow another turtle to the stimulus indicating food, but also, in the absence of the demonstrator, to approach the correct stimulus regardless of spatial position. Therefore, all four P. nelsoni turtles tested showed evidence of stimulus enhancement learning. This is the first experimental study of social learning in any aquatic reptile demonstrating that they have the ability to learn from conspecifics.
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training and long term memory of a novel food acquisition task in a turtle Pseudemys nelsoni
Behavioural Processes, 2007Co-Authors: Karen M Davis, Gordon M BurghardtAbstract:We developed a shaping procedure for training Florida red-bellied cooters, Pseudemys nelsoni, to dislodge clear plastic bottles to obtain food pellets. The animals were then trained in a 2-choice problem to choose only the bottle containing pellets. All nine turtles learned the task of knocking over bottles for food. For the discrimination task, turtles chose the correct bottle 71% on average. After 2 months (82-84 days), and again after another 7.5 months (228 days) of no interaction with the bottles, turtles were retested and many retained both the response and the discrimination (mean success rates 77-81%), with significant savings in retraining all turtles. The turtles showed two basic response strategies, which changed across time for some individuals. This study demonstrates that turtles can learn and retain a novel skill in a laboratory context.
Alan M Brichta - One of the best experts on this subject based on the ideXlab platform.
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functional architecture of vestibular primary afferents from the posterior semicircular canal of a turtle Pseudemys trachemys scripta elegans
The Journal of Comparative Neurology, 1994Co-Authors: Alan M Brichta, E H PetersonAbstract:Physiological studies inmany vertebrates indicate that vestibular primary afferents are not a homogeneous population. Such date raise the question of what structural mechanisms underlie these physiological differeneces and what functional role is played by afferents of each type. We have begun to answer these questions by characterizing the architecture of 110 afferents innervating the posterior canal of Pseudemys scripta. We emphasize their spatial organization because experimental evidence suggests that afferent physiological properties exhibit significant spatial heterogeneity. The sensory surface of the posterior canal comprises paired, triangular hemicristae, which are innervated by two afferent types. Bouton afferents (66% of total afferents) are found over the entire sensory surface. They differ significantly in the shape and size of their collecting areas, number of boutons, soma size, and axon diameter; this morphological variation is systematically related to the afferent's spatial postion. In addition, multivariate analyses suggest that bouton afferents may comprise two subtypes: α afferents have delicate processes and are found throughout the crista; β afferents are more robust and are concentrated preferentially toward the canal center. Calyx-bearing afferents comprise two morphological subtypes: dimorphs (13% of total afferents) bear calyceal and bouton endings; calyceal afferents (21%) bear calyceal endings only. Both types occur exclusively in an elliptical region near the center of each hemicrista; their morphology varies with radial distance from the center of this elliptical region. Our data provide evidence that in Pseudemys:(1) the classical vestibular afferents types (bouton, calyx, dimorph) are structurally heterogeneous, and (2) their spatial sampling characteristic are highly structured and distinctive for each type. These spatial patterns may shed light on regional differences in physiological profiles of vestibular afferents, and they raise questions about the role of this spatial heterogeneity in signaling head movement. © 1994 Wiley-Liss, Inc.
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functional architecture of vestibular primary afferents from the posterior semicircular canal of a turtle Pseudemys trachemys scripta elegans
The Journal of Comparative Neurology, 1994Co-Authors: Alan M Brichta, E H PetersonAbstract:Physiological studies in many vertebrates indicate that vestibular primary afferents are not a homogeneous population. Such data raise the question of what structural mechanisms underlie these physiological differences and what functional role is played by afferents of each type. We have begun to answer these questions by characterizing the architecture of 110 afferents innervating the posterior canal of Pseudemys scripta. We emphasize their spatial organization because experimental evidence suggests that afferent physiological properties exhibit significant spatial heterogeneity. The sensory surface of the posterior canal comprises paired, triangular hemicristae, which are innervated by two afferent types. Bouton afferents (66% of total afferents) are found over the entire sensory surface. They differ significantly in the shape and size of their collecting areas, number of boutons, soma size, and axon diameter; this morphological variation is systematically related to the afferent's spatial position. In addition, multivariate analyses suggest that bouton afferents may comprise two subtypes: alpha afferents have delicate processes and are found throughout the crista; beta afferents are more robust and are concentrated preferentially toward the canal center. Calyx-bearing afferents comprise two morphological subtypes: dimorphs (13% of total afferents) bear calyceal and bouton endings; calyceal afferents (21%) bear calyceal endings only. Both types occur exclusively in an elliptical region near the center of each hemicrista; their morphology varies with radial distance from the center of this elliptical region. Our data provide evidence that in Pseudemys: (1) the classical vestibular afferent types (bouton, calyx, dimorph) are structurally heterogeneous, and (2) their spatial sampling characteristics are highly structured and distinctive for each type. These spatial patterns may shed light on regional differences in physiological profiles of vestibular afferents, and they raise questions about the role of this spatial heterogeneity in signaling head movement.
Sid Gilman - One of the best experts on this subject based on the ideXlab platform.
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gabaa gabab and benzodiazepine binding sites in the cerebellar cortex of the red eared turtle Pseudemys scripta
Brain Research, 1992Co-Authors: Roger L Albin, Sid GilmanAbstract:We used receptor autoradiography to ascertain the distribution of GABAA and GABAB binding sites in the cerebellar cortex of the red-eared turtle (Pseudemys scripta). GABAA binding sites were found in both molecular and granule cell layers with highest levels in the granule cell layer. GABAB binding sites were found at highest level in the molecular layer. Benzodiazepine binding sites were found in approximately equal abundance in both layers. Little binding of any ligand was seen in the Purkinje cell layer. Our results are similar to those found in mammals and other non-mammalian vertebrates and indicate that the organization of inhibitory pathways of the cerebellar cortex has been conserved in the course of vertebrate evolution.
