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.