Expression of the neuronal calcium sensor protein family in the rat brain

The neuronal calcium sensor proteins are members of the calcium-binding pro tein superfamily. They control localized calcium signalling on membranes an d may make G-protein cascades sensitive to cytosolic calcium. The family me mbers are recoverin (visinin, S-modulin), neuronal calcium sensor-1 (freque nin), hippocalcin, neuronal visinin-like protein-1 (visinin-like protein, n eurocalcin-alpha), nenronal visinin-like protein-2 and neuronal visinin-lik e protein-3. Recoverin is expressed only in the retina and pineal gland. Us ing in situ hybridization, we mapped the expression of the other neuronal c alcium sensor protein genes in the adult rat brain. Neuronal visinin-like p rotein-1 messenger RNA has a widespread distribution and is abundant in all brain areas except the caudate-putamen. Neuronal calcium sensor-1 gene exp ression is pan-neuronal. Neuronal calcium sensor-1 messenger RNA is present in the dendrites of hippocampal pyramidal and granule cells, suggesting a specific role in dendritic function. Hippocalcin and neuronal visinin-like protein-2 are mainly expressed in the forebrain and have similar expression patterns (neocortex, hippocampus and caudate-putamen). Neuronal visinin-li ke protein-3 has the most restricted expression; its highest expression lev el is in the cerebellum (Purkinje and granule cells). However, the neuronal visinin-like protein-3 gene is also expressed in many ventral nuclei throu ghout the fore- and midbrain, in the medial habenulae, and in the superior and inferior colliculi. The neuronal calcium sensor proteins are a relatively unexplored family of Ca2+-binding proteins. They are likely to be involved in many diverse areas of neuronal signalling. In this paper, we describe their expression in the rat brain as determined by in situ hybridization. As all five neuronal cal cium sensor protein genes have distinctive expression patterns, they probab ly perform specific functions. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights reserved.