Ca2+/calmodulin-dependent kinase II immunoreactivity in the rat hypothalamus.

Abstract

The distribution of Ca2+/calmodulin-dependent kinase II (CaMKII) in the rat hypothalamus was studied using immunohistochemistry. Differences in labelling density were seen both between different nuclei and within nuclei. Dense labelling of cell bodies and dendrites was present in several nuclei, including the medial preoptic, suprachiasmatic, ventromedial and arcuate nuclei. In the paraventricular nucleus many labelled neurones were seen in some parvocellular regions, whereas its posterior magnocellular part was unlabelled. Dense terminal-like labelling was present in, for example, the ventromedial nucleus and the supramammillary nucleus. We suggest that differences in CaMKII distribution reflect differences in the mechanisms of calcium signalling in these neurones, which may be related to their different neurochemical phenotypes and/or connective relationships.