[Abstract Title]. - Society for Neuroscience

Title: Anxiolytic-like effect of TRPV1 receptor antagonism in the medial prefrontal cortex and
central gray
Authors: *A. B. TERZIAN 1 , D. C. AGUIAR 1 , F. A. MOREIRA 2 , F. S. GUIMARÃES 1 ;
1 Phamacology, FMRP - USP, Ribeirao Preto, Brazil; 2 Univ. of Mainz, Mainz, Germany
Abstract: Introduction: The so-called capsaicin vanilloid receptor, VR1, is a member of the TRP
family of ion channels (TRPV1) and is widely found on small- and medium-sized primary
afferent neurons and in diverse areas of the central nervous system, including the dorsolateral
periaqueductal gray (dlPAG) and medial prefrontal cortex (mPFC). Both structures have been
closely associated with defensive responses but the role of local TRPV1 receptors in these
responses is largely unknown. In a previous study we found that intra-dlPAG administration of
capsazepine (CPZ, 10-60 nmol), a TRPV1 receptor antagonist, produced anxiolytic-like effects
at the higher (60 nmol) dose in the elevated plus maze. The aim of the present study was to
confirm these anxiolytic-like effects in another model of anxiety, the Vogel conflict test (VCT).
In the same test we also investigated the effects of CPF microinjection into the mPFC. Methods:
Water-deprived male Wistar rats (n=3-6) with cannula aimed at the dlPAG (unilateral) or the
mPFC (bilateral) received local microinjections of CPZ (60 nmol/0.2microL) or vehicle (DMSO)
and were submitted to the VCT. Results: CPZ significantly increased the number of punished
licks indicating an anxiolytic-like effect (Vehicle, dlPAG: 62.6+/-8.6, CPZ, dlPAG: 178.0+/-13.0
F2,11= 6.49, p