Galanin microinjection into the dorsal periaqueductal gray matter produces paradigm-dependent anxiolytic effects.

We examined the effects of galanin microinjections in the dorsal PAG (dPAG) on the performance of rats in different models of anxiety. Male Wistar rats (n=7-12) were implanted with guide cannulae in the dPAG. They received microinjections of either galanin (0.3, 1.0, and 3.0nmol) or vehicle and were tested in the Vogel conflict test (VCT), elevated plus maze (EPM), and elevated T-maze (ETM). Rats that were tested in the ETM were further evaluated for exploratory activity in the open field test (OFT). Galanin microinjections had no effects on anxiety-like behavior in the EPM or VCT or exploratory activity in the EPM or OFT. In the ETM, however, microinjections of 3nmol galanin impaired learned anxiety (i.e., avoidance of the open arms) without changing unconditioned fear (i.e., escape from the open arms). The present data suggest that galanin transmission in the dPAG inhibits the acquisition of anxiety-like responses in the ETM.
PMID: 26751815 [PubMed - as supplied by publisher]

Source: Brain Research Bulletin - January 2, 2016 Category: Neurology Authors: Soares FR, Silote GP, Almeida-Santos AF, Aguiar DC, Schenberg LC, Beijamini V Tags: Brain Res Bull Source Type: research