EFFECTS OF MATERNAL ETHANOL-CONSUMPTION AND BUSPIRONE TREATMENT ON 5-HT1A AND 5-HT2A RECEPTORS IN OFFSPRING

In utero ethanol exposure results in a decreased concentration of sero tonin (5-HT) in brain regions containing the cell bodies of 5-HT neuro ns and their cortical projections. The concentration of 5-HT reuptake sites is also reduced in several brain areas. The present study extend ed prior work by evaluating the effects of chronic maternal ethanol co nsumption and maternal buspirone treatment on 5-HT1A and 5-HT2A recept ors in multiple brain areas of offspring. Receptors were quantitated e arly in postnatal development and at an age when the 5-HT networks are normally well-established. Because fetal 5-HT functions as an essenti al neurotrophic factor, these studies also determined whether treatmen t of pregnant rats with buspirone, a 5-HT1A agonist, could overcome th e effects of the fetal 5-HT deficit and prevent ethanol-associated rec eptor abnormalities, The results demonstrated that in utero ethanol ex posure significantly alters the binding of 0.1 nM [H-3]-8-hydroxy-dipr opylaminotetralin to 5-HT1A receptors in developing animals, Ethanol i mpaired the development of 5-HT1A receptors in the frontal cortex, par ietal cortex, and lateral septum; these receptors did not undergo the normal developmental increase between postnatal days 19 and 35, The de ntate gyrus was also sensitive to the effects of in utero ethanol expo sure. 5-HT1A receptors were increased in this region at 19 days. Mater nal buspirone treatment prevented the ethanol-associated abnormalities in 5-HT1A receptors in the dentate gyrus, frontal cortex, and lateral septum. Neither maternal ethanol consumption nor buspirone treatment altered the binding of 2 nM [H-3]ketanserin to 5-HT2A receptors in the ventral dentate gyrus, dorsal raphe, parietal and frontal cortexes, s triatum, substantia nigra, or nucleus accumbens.