Sex-Related Differences in PACAP Expression in the PVT of Rats
Both the paraventricular nucleus of the thalamus (PVT) and the neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), are associated with motivated and affective behaviors, including alcohol drinking and binge eating, and sex-related differences in neuronal activity have been identified in the PVT. While PACAP has been found to be densely expressed in the PVT of male rodents, with the isoform PACAP-27 more prevalent than PACAP-38, this remains to be characterized in females. The purpose of this research was to examine PACAP in the PVT of female rats and to determine if there are sex-related differences in this expression. Thus, we performed fluorescent immunohistochemistry for PACAP-27 and PACAP-38 on tissue containing the PVT from adult, male and female Sprague-Dawley rats (n = 5/sex). Using confocal microscopy and ImageJ, we determined that female rats had a higher percentage of cells that co-labeled with PACAP-27 and PACAP-38 in the PVT, across the anterior, middle, and posterior subregions. These findings highlight sex-related differences in PACAP in the PVT, and they suggest that PACAP may underlie some established sex-related differences in motivated and affective behavior.
Both the paraventricular nucleus of the thalamus (PVT) and the neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), are associated with motivated and affective behaviors, including alcohol drinking and binge eating, and sex-related differences in neuronal activity have been identified in the PVT. While PACAP has been found to be densely expressed in the PVT of male rodents, with the isoform PACAP-27 more prevalent than PACAP-38, this remains to be characterized in females. The purpose of this research was to examine PACAP in the PVT of female rats and to determine if there are sex-related differences in this expression. Thus, we performed fluorescent immunohistochemistry for PACAP-27 and PACAP-38 on tissue containing the PVT from adult, male and female Sprague-Dawley rats (n = 5/sex). Using confocal microscopy and ImageJ, we determined that female rats had a higher percentage of cells that co-labeled with PACAP-27 and PACAP-38 in the PVT, across the anterior, middle, and posterior subregions. These findings highlight sex-related differences in PACAP in the PVT, and they suggest that PACAP may underlie some established sex-related differences in motivated and affective behavior.