A transient embryonic dopamine receptor inhibits growth cone motility and neurite outgrowth in a subset of avian retina neurons.

To investigate the possible developmental significance of a transient dopamine receptor in the avian central nervous system, we examined the effects of dopamine on the morphology and motility of cultured retina neurons. Neurite arborization was significantly reduced by chronic dopamine stimulation. Using continuous video microscope monitoring, we observed that a subset of neurons responded to short-term dopamine with decreased filopodial activity and retracted neurites. The effects of dopamine could be blocked or reversed by haloperidol or SCH23390 and forskolin produced a response similar to dopamine, indicating the morphological changes were mediated by D1-receptor stimulation of adenylate cyclase.