【Objective】 Calcitonin gene-related peptide (CGRP) is a neuropeptide consisting of 37 amino acids produced by splicing difference from the calcitonin, and has strong vasodilation. We have shown that the expression of CGRP was significantly decreased in depression-like model mice hippocampus. CGRP administration into the mice brain before the beginning of stress exposure,　normalized the behavioral dysfunction with increase never growth factor. In the present study, we investigated the role of highly CGRP expressing gene steadily using CGRP over expressing, CGRP transgenic (Tg) mice.
【Methods】 8 weeks to 9 weeks old CGRP (Tg) mice were used. Same age of C57BL/6J mice were used as the control group. Behavioral tests were conducted on open field test, forced swimming test (FST), tail suspension test (TST) and sucrose preference test to evaluate depression-like behavior.
【Results】 Immobility time in the FST and TST in CGRP Tg mice were significantly longer than C57BL/6J mice. In contrast, in the sucrose preference test, which measures anhedonic-like deficits, there were no significant differences. Furthermore, in the open field test, which measures spontaneous behavior decreased in CGRP Tg mice. These results suggest that prolonged immobility time of CGRP Tg mice is not due to depressive symptoms, but spontaneous behavior may have an effect.