Effects of repeated amphetamine treatment on regional GABA(A) receptor binding

The present study examined the effects of repeated exposure to amphetamine on GABA, receptor binding in cortical and subcortical areas. The goal of th e study was to determine whether changes in specific binding were related t o behavioral sensitization. Animals were exposed to either saline (0.3 ml, s.c.; n = 12) or D-amphetamine (2.5 mg/kg, s.c.; n = 12) for 6 consecutive days and sacrificed after a 14-day withdrawal period. Differences in GABA(A ), receptor binding in these two groups of animals were assessed using the GABA(A) receptor antagonist [H-3]SR 95531. To verify that the preceding tre atment regimen led to the development of behavioral sensitization, a separa te set of animals (n = 8/group) was exposed to the same regimen and challen ged with D-amphetamine (2.5 mg/kg, s.c.) after the 14-day withdrawal period . As expected, preexposure to amphetamine led to the development of ampheta mine sensitization, There were no differences in GABA(A) receptor binding i n animals preexposed to saline and amphetamine in the prefrontal cortex, ca udate-putamen, hypothalamus, or cerebellum. These findings do not provide s upport for the idea that changes in GABA(A) receptor binding in the medial prefrontal cortex or various subcortical areas are related to the developme nt of behavioral sensitization. (C) 1999 Elsevier Science B.V, All rights r eserved.