1. Increased behavioral neurosteroid sensitivity in a rat line selectively bred for high alcohol sensitivity
- Author
-
Mei Xu, Maija Sarviharju, Esa R. Korpi, Alessandro Guidotti, Mikko Uusi-Oukari, Riikka Mäkelä, Flavia di Michele, Per H. Rosenberg, Carmelo Furnari, and Elena Romeo
- Subjects
Male ,Allopregnanolone ,GABAA receptor ,Motor impairment ,Pregnanolone ,Progesterone ,Selected rat line ,medicine.medical_specialty ,Cerebellum ,Neuroactive steroid ,Breeding ,Motor Activity ,Biology ,Settore BIO/09 ,chemistry.chemical_compound ,GABA receptor ,Internal medicine ,Neuromodulation ,medicine ,Animals ,Receptor ,gamma-Aminobutyric Acid ,Pharmacology ,Behavior, Animal ,Dose-Response Relationship, Drug ,Ethanol ,Brain ,Receptors, GABA-A ,ANT ,Rats ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Female - Abstract
Acute administration of a neurosteroid 5beta-pregnan-3alpha-ol-20-one induced a greater impairment in motor performance of the selectively bred alcohol-sensitive (ANT) than alcohol-insensitive (AT) rats. This difference was not associated with the sensitivity of gamma-aminobutyrate type A (GABA(A)) receptors, as 5alpha-pregnan-3alpha-ol-20-one (allopregnanolone) decreased the autoradiographic signals of t-butylbicyclophosphoro[35S]thionate binding to GABA(A) receptor-associated ionophores more in the brain sections of AT than ANT rats. Nor was the difference associated with baseline levels of neuroactive progesterone metabolites, as 5alpha-pregnan-3,20-dione (5alpha-DHP) and 5alpha-pregnan-3alpha-ol-20-one were lower in the ANT rats. After ethanol (2 g/kg, i.p.) administration and the subsequent motor performance test, the increased brain concentrations of these metabolites were still lower in the ANT than AT rats, although especially in the cerebellum the relative increases were greater in the ANT than AT rats. The present data suggest that the mechanisms mediating neurosteroid-induced motor impairment are susceptible to genetic variation in rat lines selected for differences in ethanol intoxication.
- Published
- 2001