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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Functional mapping of the circuits involved in the expression of contextual fear responses in socially defeated animals

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Faturi, C. B. [1] ; Rangel, Jr., M. J. [1] ; Baldo, M. V. C. [2] ; Canteras, N. S. [1]
Total Authors: 4
[1] Univ Sao Paulo, Dept Anat, Inst Biomed Sci, BR-05508900 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Brain Structure & Function; v. 219, n. 3, p. 931-946, MAY 2014.
Web of Science Citations: 10

In this study, we have aimed at outlining the neural systems underlying the expression of contextual fear to social defeat. First, we have developed an experimental procedure, where defeated animals could express, without the presence of a dominant aggressive male, robust and reliable conditioned fear responses to the context associated with social defeat. Next, by examining the pattern of Fos expression, we have been able to outline a brain circuit comprising septal and amygdalar sites, as well as downstream hypothalamic paths, putatively involved in the expression of contextual fear to social threat. Of particular relevance, we have found that exposure to a defeat-associated context results in a striking Fos up-regulation in the dorsomedial part of the dorsal premammillary nucleus (PMDdm). To further understand the role of the PMDdm in the circuit organizing conditioned fear to social threats, we have been able to observe that pharmacological blockade of the PMDdm reduced fear responses to a social defeat-associated context. Next, we observed that pharmacological blockade of the dorsomedial part of the periaqueductal gray, one of the main targets of the PMDdm, produced an even higher reduction of conditioned fear in defeated intruders, and appears as an important node for the expression of contextual defensive responses to social threats. The present results help to elucidate the basic organization of the neural circuits underlying contextual conditioned responses to social defeat, and reveal that they share at least part of the same circuit involved in innate responses to social defeat to an aggressive conspecific. (AU)

FAPESP's process: 11/02425-3 - The role of the dorsal premammillary nucleus and its main targets in the neuroendocrine and behavioral responses observed after social defeat
Grantee:Newton Sabino Canteras
Support type: Regular Research Grants