Extended treatment with typical and atypical antipsychotic drugs: Differential effects on the densities of dopamine D2-like and GABAA receptors in rat striatum

Brian Dean, Tabasum Hussain, Elizabeth Scarr, Geoffrey Pavey, David L. Copolov

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

In situ radioligand binding and quantitative autoradiography have been used to measure the density of striatal D1-like, D2-like, and GABAA receptors in rats treated with haloperidol at 0.01 or 0.1 mg/kg/day or chlorpromazine, olanzapine or clozapine at 0.1 or 1.0 mg/kg/day for 1, 3 or 7 months. [3H]SCH23390 binding to D1-like receptors was not changed by any drug treatments. There were significant increases in [3H]nemonapride binding to D2-like receptors at different time points due to treatment with haloperidol, chlorpromazine and olanzapine. By contrast, treatment with clozapine and olanzapine caused a time-dependent decrease in [3H]muscimol binding to the GABAA receptor. These data suggest that treatment with atypical antipsychotic drugs, but not typical antipsychotic drugs, affect striatal GABAergic neurons. In addition, it would appear that clozapine might be unique in that it does not increase dopamine-D2 like receptor density at doses which would be predicted to have antipsychotic effects in humans. The extent to which such changes are involved in the therapeutic effects of drugs such as olanzapine and clozapine remains to be determined.

Original languageEnglish
Pages (from-to)1257-1268
Number of pages12
JournalLife Sciences
Volume69
Issue number11
DOIs
Publication statusPublished - 3 Aug 2001
Externally publishedYes

Keywords

  • Antipsychotic drugs
  • Dopamine receptors
  • GABA receptors

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