Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala

GABAergic medial paracapsular intercalated (Imp) neurons of amygdala are thought of as playing a central role in fear learning and extinction. We report here that the synaptic network formed by these neurons exhibits distinct short-term plastic synaptic responses. The success rate of synaptic events...

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Main Authors: Geracitano, R, Kaufmann, W, Szabo, G, Ferraguti, F, Capogna, M
Format: Journal article
Language:English
Published: 2007
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author Geracitano, R
Kaufmann, W
Szabo, G
Ferraguti, F
Capogna, M
author_facet Geracitano, R
Kaufmann, W
Szabo, G
Ferraguti, F
Capogna, M
author_sort Geracitano, R
collection OXFORD
description GABAergic medial paracapsular intercalated (Imp) neurons of amygdala are thought of as playing a central role in fear learning and extinction. We report here that the synaptic network formed by these neurons exhibits distinct short-term plastic synaptic responses. The success rate of synaptic events evoked at a frequency range of 0.1-10 Hz varied dramatically between different connected cell pairs. Upon enhancing the frequency of stimulation, the success rate increased, decreased or remained constant, in a similar number of cell pairs. Such synaptic heterogeneity resulted in inhibition of the firing of the postsynaptic neurons with different efficacies. Moreover, we found that the different synaptic weights were mainly determined by diversity in presynaptic release probabilities rather than postsynaptic changes. Sequential paired recording experiments demonstrated that the same presynaptic neuron established the same type of synaptic connections with different postsynaptic neurons, suggesting the absence of target-cell specificity. Conversely, the same postsynaptic neuron was contacted by different types of synaptic connections formed by different presynaptic neurons. A detailed anatomical analysis of the recorded neurons revealed discrete and unexpected peculiarities in the dendritic and axonal patterns of different cell pairs. In contrast, several intrinsic electrophysiological responses were homogeneous among neurons, and synaptic failure counts were not affected by presynaptic cannabinoid 1 or GABAB receptors. We propose that the heterogeneous functional connectivity of Imp neurons, demonstrated by this study, is required to maintain the stability of firing patterns which is critical for the computational role of the amygdala in fear learning and extinction. © 2007 The Authors. Journal compilation © 2007 The Physiological Society.
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spelling oxford-uuid:b37f682b-6a7b-4eec-9572-9b06a6eeefe52022-03-27T04:19:35ZSynaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdalaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b37f682b-6a7b-4eec-9572-9b06a6eeefe5EnglishSymplectic Elements at Oxford2007Geracitano, RKaufmann, WSzabo, GFerraguti, FCapogna, MGABAergic medial paracapsular intercalated (Imp) neurons of amygdala are thought of as playing a central role in fear learning and extinction. We report here that the synaptic network formed by these neurons exhibits distinct short-term plastic synaptic responses. The success rate of synaptic events evoked at a frequency range of 0.1-10 Hz varied dramatically between different connected cell pairs. Upon enhancing the frequency of stimulation, the success rate increased, decreased or remained constant, in a similar number of cell pairs. Such synaptic heterogeneity resulted in inhibition of the firing of the postsynaptic neurons with different efficacies. Moreover, we found that the different synaptic weights were mainly determined by diversity in presynaptic release probabilities rather than postsynaptic changes. Sequential paired recording experiments demonstrated that the same presynaptic neuron established the same type of synaptic connections with different postsynaptic neurons, suggesting the absence of target-cell specificity. Conversely, the same postsynaptic neuron was contacted by different types of synaptic connections formed by different presynaptic neurons. A detailed anatomical analysis of the recorded neurons revealed discrete and unexpected peculiarities in the dendritic and axonal patterns of different cell pairs. In contrast, several intrinsic electrophysiological responses were homogeneous among neurons, and synaptic failure counts were not affected by presynaptic cannabinoid 1 or GABAB receptors. We propose that the heterogeneous functional connectivity of Imp neurons, demonstrated by this study, is required to maintain the stability of firing patterns which is critical for the computational role of the amygdala in fear learning and extinction. © 2007 The Authors. Journal compilation © 2007 The Physiological Society.
spellingShingle Geracitano, R
Kaufmann, W
Szabo, G
Ferraguti, F
Capogna, M
Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title_full Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title_fullStr Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title_full_unstemmed Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title_short Synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
title_sort synaptic heterogeneity between mouse paracapsular intercalated neurons of the amygdala
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