CHANGES IN CCK MESSENGER-RNA IN HIPPOCAMPAL-NEURONS FOLLOWING FIMBRIA-FORNIX TRANSECTION

PREPROCHOLECYSTOKININ (CCK) mRNA expression was measured in a subset o f hippocampal interneurones after transection of afferent septohippoca mpal fibres in the fimbria fornix. Two weeks after the lesions were ma de, CCK mRNA levels were significantly lower in these neurones on the side ipsilateral to the lesion compared with equivalent neurones on th e unlesioned side. These findings suggest that axotomizing lesions can change gene expression in denervated target cells, and that CCK mRNA levels in hippocampal interneurones may be modulated by afferent septo hippocampal input.