Regional densities of benzodiazepine sites in the CNS of alcohol-naive P and NP rats

R. J. Thielen, W. J. McBride, E. Chernet, L. Lumeng, T. K. Li

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The regional densities of benzodiazepine (BDZ) recognition sites coupled to GABA, receptors were studied in ethanol-naive alcohol-preferring (P) and -nonpreferring (NP) lines of rats by using quantitative autoradiography to measure the amount of 2 nM [3H]flunitrazepam (FNZ) binding in the absence and presence of 100 μM GABA. Lower values (p < 0.025) for [3H]FNZ binding (in the absence of GABA) were observed in the prefrontal cortex, layer 4 of the parietal cortex, and the nucleus accumbens shell of the P relative to the NP line. GABA significantly (p < 0.025) stimulated [3H]FNZ binding in all 50 central nervous system regions examined in both the P and the NP rats. The largest percent increases (190-220%) were observed in the prefrontal, cingulate, frontal, and parietal cortices; shell and core nucleus accumbens; caudate putamen; dorsal lateral, intermediate lateral, ventral lateral, and medial septal nuclei; and lateral hypothalamus. In several layers of the frontal and parietal cortices, a 25-30% greater net or percent increase (p < 0.025) in GABA-enhanced [3H]FNZ binding was observed in the P rats compared with the NP rats. In contrast, lower net or percent increases (p < 0.025) in GABA-enhanced [3H]FNZ binding were found in the entorhinal cortex, the mediodorsal thalamus, and the dorsal CA3 area and middle dentate gyrus of the posterior hippocampus of the P line relative to the NP line. The present findings suggest that there are innate regional differences between P and NP rats in the densities and/or affinities of BDZ recognition sites and in the coupling between the GABA, and BDZ binding sites.

Original languageEnglish (US)
Pages (from-to)875-882
Number of pages8
JournalPharmacology Biochemistry and Behavior
Volume57
Issue number4
DOIs
StatePublished - Aug 1 1997

Keywords

  • Alcohol-preferring rats
  • Autoradiography
  • Benzodiazepine recognition sites
  • Flunitrazepam binding
  • GABA(A) receptors

ASJC Scopus subject areas

  • Biochemistry
  • Behavioral Neuroscience
  • Pharmacology

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