AUTORADIOGRAPHIC ANALYSIS OF D-1 AND D-2 DOPAMINERGIC RECEPTORS IN RAT-BRAIN AFTER PARADOXICAL SLEEP-DEPRIVATION

Previous work had shown that paradoxical sleep deprivation (PSD) resul ts in potentiation of several apomorphine-induced behaviors, leading t o the suggestion that PSD induces an upre,oulation of brain dopamine r eceptors. In this study, quantitative receptor autoradiography was use d to verify whether PSD does, in fact, induce alterations in D-1 or D- 2 receptor binding, and to investigate the regional brain specificity of such effects. After 96 h of PSD, [H-3]SCH-23390 binding to D-1 rece ptors was examined in 30 different brain areas of 10 experimental and 10 cage control rats. [H-3]Spiperone was used to label D-2 sites in ad jacent tissue sections. Results revealed a 39% increase in [H-3]SCH 23 390 binding in the entorhinal cortex of PSD rats (p < 0.05), but no ot her changes in any of the remaining 29 brain areas examined. In contra st, [H-3]spiperone binding was significantly elevated in the n. accumb ens (+45%) and in all subregions of the caudate-putamen (range: +13% t o +23%). These results, thus, provide evidence that PSD increases D-2 but not D-1 receptor binding in brain. The present results also sugges t that upregulated D-2 receptors can account for the previously report ed changes in apomorphine-induced behaviors after PSD.