Evidence for the existence of α- and β-adrenoceptors on neurones and glial cells of cultured rat central nervous system—an autoradiographic study

Abstract

The cellular localization of the binding of radioactive noradrenaline and α- and β-adrenoceptor antagonists was studied in organotypic cultures of rat cerebellum, brain stem and spinal cord using autoradiography. In cerebellar cultures, many neurones, which appeared to be Purkinje cells, were labelled by [ 3H]noradrenaline and by the β-antagonists [ 3H]dihydroalprenolol and [ 3H]carazolol, whereas no binding of the α-antagonists [ 3H]prazosin and [ 3H]rauwolscine was detected. In cultures of spinal cord and brain stem, [ 3H]noradrenaline and the β-antagonists were bound to many large neurones. Binding of [ 3H]α-antagonists was observed to a small number of brain stem and spinal neurones, the labelling being much weaker than that produced by the [ 3H]β-antagonists. The antidepressant [ 3H]desmethylimipramine was bound to many neurones and glial cells in cerebellar, brain stem and spinal cord cultures. Glial cells also possessed binding sites for [ 3H]noradrenaline and α- and β-adrenoceptor antagonists, findings that are consistent with recent electrophysiological observations which indicate the existence of α- and β-adrenoceptors on cultured astrocytes.