This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The inferior olivary complex (IOC) is the sole source of climbing fiber afferents to the cerebellum. Any alteration of climbing fiber firing rate by peptide neuromodulation may affect Purkinje cell firing and cerebellar activity. A previous study identified peptide immunoreactivity within the adult mouse IOC (J. Chem. Neuroanat. 12:211, 1997). Following Kooy?s terminology (Folia Neurobiol. 10:205,1917) both calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) densely labeled small varicosities throughout the inferior olive and large varicosities in the dorsal cap of Kooy (dc) and lateral dorsal accessory olive (DAO). CGRP also labeled large varicosities in the ventrolateral outgrowth (vlo). The similarity in size and distribution of varicosities labeled by CGRP and CCK in the original study suggested colocalization of these peptides. This study further investigates possible colocalization using double-labeling immunofluorescence. These data demonstrate faintly double-labeled cell bodies throughout all regions of the inferior olivary complex. In the dc, vlo and some cells of the caudal MAO and rostral DAO, it is evident that CGRP labels the nucleus, but CCK does not. Double-labeled varicosities are localized to the dc, vlo, the lateral dorsal accessory olive (DAO) and the lateral, caudal MAO. Single-labeled varicosities are also present in these areas. These studies suggest that CGRP and CCK may serve dual as well as independent functions within the IOC. These data serve as a foundation for future studies addressing the functional role of these peptides in the IOC. This publication was made possible by NIH Grant Number P20 RR16469 from the BRIN Program of the National Center for Research Resources.
Showing the most recent 10 out of 322 publications
