Dorsal and Ventral Hippocampus Modulate Autonomic Responses but Not Behavioral Consequences Associated to Acute Restraint Stress in Rats

Author(s)

Scopinho, America A. ^[1] ; Lisboa, Sabrina F. S. ^[1] ; Guimaraes, Francisco S. ^{[2, 1]} ; Correa, Fernando M. A. ^[1] ; Resstel, Leonardo B. M. ^{[2, 1]} ; Joca, Samia R. L. ^{[3, 2]}

Affiliation

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Pharmacol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Ctr Interdisciplinary Res Appl Neurosci NAPNA, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, Dept Chem & Phys, Pharmacol Lab, Sao Paulo - Brazil

• Document type: Journal article
• Source: PLoS One; v. 8, n. 10 OCT 17 2013.
• Web of Science Citations: 13

Abstract

Recent evidence has suggested that the dorsal (DH) and the ventral (VH) poles of the hippocampus are structurally, molecularly and functionally different regions. While the DH is preferentially involved in the modulation of spatial learning and memory, the VH modulates defensive behaviors related to anxiety. Acute restraint is an unavoidable stress situation that evokes marked and sustained autonomic changes, which are characterized by elevated blood pressure (BP), intense heart rate (HR) increases, skeletal muscle vasodilatation and cutaneous vasoconstriction, which are accompanied by a rapid skin temperature drop followed by body temperature increases. In addition to those autonomic responses, animals submitted to restraint also present behavioral changes, such as reduced exploration of the open arms of an elevated plus-maze (EPM), an anxiogenic-like effect. In the present work, we report a comparison between the effects of pharmacological inhibition of DH and VH neurotransmission on autonomic and behavioral responses evoked by acute restraint stress in rats. Bilateral microinjection of the unspecific synaptic blocker cobalt chloride (CoCl2, 1mM) into the DH or VH attenuated BP and HR responses, as well as the decrease in the skin temperature, elicited by restraint stress exposure. Moreover, DH or VH inhibition before restraint did not change the delayed increased anxiety behavior observed 24 h later in the EPM. The present results demonstrate for the first time that both DH and VH mediate stress-induced autonomic responses to restraint but they are not involved in the modulation of the delayed emotional consequences elicited by such stress. (AU)

• FAPESP's process: 11/17281-7 - Involvement of epigenetic mechanisms induced by DNA methylation on stress-induced behavioral consequences and on the expression of genes involved in the neurobiology of depression
• Grantee: Sâmia Regiane Lourenço Joca
• Support type: Regular Research Grants
• FAPESP's process: 12/09300-4 - Bed nucleus of the stria terminalis noradrenergic system modulates contextual fear conditionig: possible interaction with CRF and glutamatergic and nitrergic neurotransmission
• Grantee: Leonardo Resstel Barbosa Moraes
• Support type: Regular Research Grants