| Abstract: | 3H]-(-)-Sulpiride and 3H]-spiperone binding was compared in rat amygdala, nucleus accumbens and striatum, using (+/-)-sulpiride to define specific binding. 3H]-(-)-Sulpiride bound to twice as many sites in amygdala and nucleus accumbens as 3H]-spiperone. 3H]-(-)-Sulpiride binding was directed to these additional sites by using 1 microM spiperone to mask dopaminergic binding. The binding of 3H]-(-)-sulpiride to these sites was high affinity, reversible, Na+-dependent, but not stereospecific. Metoclopramide, tiapride and antidepressant medications, but not other neuroleptics, ADTN, or serotonin displaced 3H]-(-)-sulpiride binding to these sites. These data suggest that 3H]-(-)-sulpiride labels mesolimbic sites other than dopamine receptors which may mediate antidepressant effects. |
