Fos-like immunoreactivity in central nervous system of mice simultaneously exposed to the elevated plus-maze and nociception

ABSTRACT

It has been demonstrated that mice exhibit antinociception when they are exposed to the elevated plus-maze (EPM), an animal model of anxiety. To investigate which brain structures are activated during EPM exposure, the present study assessed the immunohistochemical staining for Fos-like immunoreactivity (Fos-LI) in mice intraperitoneally injected with saline or 0,6 por cente acetic acid (which produces nociception) and cofined in the open arm (threatening situation) or enclosed arm (Control) of the EPM. The following strutuctures were investigated: magnus, dorsal and median raphe nuclei (MR, DR and MnR), periaqueductal gray matter (PAG), dorsal and ventral hippocampus (DH and VH), amygdala (AMY), hypothalamus (HYP) and superior and inferior colliculi (SC and IC)...