Marco Capogna

Large intercalated neurons of amygdala relay noxious sensory information

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

  • Thomas C M Bienvenu, Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom, and.
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  • Daniela Busti, Department of Pharmacology, Innsbruck Medical University, Peter Mayr Straße 1a, 6020 Innsbruck, Austria.
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  • Benjamin R Micklem, Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom, and.
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  • Mahnaz Mansouri, Department of Pharmacology, Innsbruck Medical University, Peter Mayr Straße 1a, 6020 Innsbruck, Austria.
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  • Peter J Magill, Medical Research Council Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford OX1 3TH, United Kingdom, and.
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  • Francesco Ferraguti, Department of Pharmacology, Medical University of Innsbruck, 6020 Innsbruck, Austria marco.capogna@pharm.ox.ac.uk francesco.ferraguti@i-med.ac.at.
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  • Marco Capogna

Various GABAergic neuron types of the amygdala cooperate to control principal cell firing during fear-related and other behaviors, and understanding their specialized roles is important. Among GABAergic neurons, the so-called intercalated cells (ITCcs) are critically involved in the expression and extinction of fear memory. Tightly clustered small-sized spiny neurons constitute the majority of ITCcs, but they are surrounded by sparse, larger neurons (L-ITCcs) for which very little information is known. We report here a detailed neurochemical, structural and physiological characterization of rat L-ITCcs, as identified with juxtacellular recording/labeling in vivo. We supplement these data with anatomical and neurochemical analyses of nonrecorded L-ITCcs. We demonstrate that L-ITCcs are GABAergic, and strongly express metabotropic glutamate receptor 1α and GABAA receptor α1 subunit, together with moderate levels of parvalbumin. Furthermore, L-ITCcs are innervated by fibers enriched with metabotropic glutamate receptors 7a and/or 8a. In contrast to small-sized spiny ITCcs, L-ITCcs possess thick, aspiny dendrites, have highly branched, long-range axonal projections, and innervate interneurons in the basolateral amygdaloid complex. The axons of L-ITCcs also project to distant brain areas, such as the perirhinal, entorhinal, and endopiriform cortices. In vivo recorded L-ITCcs are strongly activated by noxious stimuli, such as hindpaw pinches or electrical footshocks. Consistent with this, we observed synaptic contacts on L-ITCc dendrites from nociceptive intralaminar thalamic nuclei. We propose that, during salient sensory stimulation, L-ITCcs disinhibit local and distant principal neurons, acting as "hub cells," to orchestrate the activity of a distributed network.

Original languageEnglish
JournalThe Journal of neuroscience : the official journal of the Society for Neuroscience
Volume35
Issue5
Pages (from-to)2044-57
Number of pages14
ISSN0270-6474
DOIs
Publication statusPublished - 4 Feb 2015
Externally publishedYes

    Research areas

  • Amygdala, Animals, Axons, Dendrites, Entorhinal Cortex, Evoked Potentials, Somatosensory, GABAergic Neurons, Interneurons, Male, Nociception, Rats, Rats, Sprague-Dawley, Receptors, GABA-A, Receptors, Metabotropic Glutamate, Thalamic Nuclei, Journal Article, Research Support, Non-U.S. Gov't

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