DIFFERENTIAL EXPRESSION OF THE GABA(A) RECEPTOR ALPHA-1 SUBUNIT IN DEVELOPING CHICKEN BRAIN

A unique segment of chicken GABA(A) receptor alpha 1 subunit was expre ssed in E. coli and used to generate an antiserum 2A specific for the subunit. The DNA fragment encoding the segment of alpha 1 was obtained by selective amplification by polymerase chain reaction (PCR) from a chicken brain cDNA library. The antiserum is characterized by its capa city to immunoprecipitate a [H-3]flunitrazepam binding protein of 50 k Da, the chicken GABA, receptor alpha 1 subunit. Subsequent immunoblott ing and immunocytochemistry analyses reveal that alpha 1 is expressed in the optic tectum and cerebellum as early as embryonic day 15 (E15), in various areas of telencephalon as early as E20 and distributed het erogeneously among different cell types. The early expression of al ma y imply its functional significance in neurotransmission.