TARGET-CELLS MODULATE DOPAMINE TRANSPORTER GENE-EXPRESSION DURING BRAIN-DEVELOPMENT

WE have analysed the expression of the dopamine transporter (DAT) gene and compared it with that of tyrosine hydroxylase, neuronal GABA tran sporter and synaptic vesicle monoamine transporter genes during pre- a nd post-natal development of rat mesencephalic dopaminergic (DA) neuro nes. Our results show that DAT transcripts are not detectable until em bryonic day (E) 15, whilst those of the other genes analysed are alrea dy present at E12. In vitro, the level of DAT gene transcription in me sencephalic E13 DA neurones is increased in coculture with target stri atal cells. Thus striatal targets cells regulate, at the transcription al level, a key step of dopaminergic neurotransmission during DA neuro ne development.