Effect of different concentrations of calcitonin gene-related peptide on the long-term potentiation in hippocampus of mice / 生理学报

The purpose of this study was to explore the effects of different concentrations of calcitonin gene-related peptide (CGRP) on long-term potentiation (LTP) in the hippocampus of mice. C57BL/6J mice (30 days old) were randomly divided into control group, three CGRP groups, and CGRP + CGRPgroup (10 mice for each group). Different concentrations of CGRP (50, 100 and 200 nmol/L) were given to the hippocampal slices of mice. The presynaptic release of neurotransmitters and the induction of LTP were measured by extracellular field recording techniques. The result showed that different concentrations of CGRP did not affect the presynaptic release of neurotransmitters, but 100 and 200 nmol/L CGRP increased the amplitude of LTP induced in the hippocampus of mice. This facilitation effect of CGRP was blocked by its specific antagonist CGRP. These results suggest that CGRP dose-dependently facilitates the induction of LTP in the hippocampus of mice through its specific receptor.

Effect of bilateral injection of calcitonin gene-related peptide into amygdala on learning and memory of mice / 生理学报

The aim of the present study was to explore the effects of different doses of calcitonin gene-related peptide (CGRP) injected into the central nucleus of amygdala on cognitive function, learning and memory of mice. C57BL/6J mice (30 days old) were randomly divided into control, sham, and three CGRP groups (10 mice for each group). Three doses of CGRP (200, 400 and 800 ng) were bilaterally administered into the central nucleus of the amygdala. Open field test was used to assess cognitive function. Novel object recognition and Morris water maze test were used to evaluate learning and memory of the mice. The results of open field test showed that 800 ng CGRP significantly increased the locomotive score. The results of novel objective recognition test showed that 400 ng CGRP significantly increased the recognition index. Compared with control group, 400 and 800 ng CGRP groups showed significantly shortened latency period and increased crossing times. Simultaneously, the latency periods of 400 and 800 ng CGRP groups were shorter than that of 200 ng CGRP group. These results suggest that bilateral injection of CGRP into amygdala dose-dependently enhances the learning and memory function of mice.