Stress-related changes in calcitonin gene-related peptide binding sites in the cat central nervous system

The possibility of area-specific changes in binding sites for CGRP in response to stress was studied in cat CNS after repeated sleep-deprivation and restriction of movement. Brain sections were obtained from a cat placed under stressful conditions for 2 h the 1st day, 6 h the 2nd day and 24 h the 3rd day. Changes in CGRP binding sites were evaluated by an in vitro autoradiographic technique with 125I-Tyr-rat-CGRP as a ligand. The autoradiograms were then compared with those of control animals. The results show decreased labelling in the cortex prefrontalis and pyriformis and in some basal ganglia (n. caudatus, claustrum, n. entopedencularis). Increased CGRP binding site densities were seen in areas involved in the integration of sensory information, in the control of endocrine secretion and in those that participate in sleep-walking cycles. These changes in CGRP binding in selective CNS areas following stress suggests that CGRP plays a role in processes of adaptation.