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.