The neuritogenic effect of myenteric plexus on striatal neurones in co-culture involves nitric oxide.

We reported previously that myenteric plexus explants promoted striatal neurite elongation in co-culture and that this effect was abolished by tetrodotoxin (TTX). Here we demonstrate that the nitric oxide synthase blocker N-nitro-L-arginine methyl ester significantly reduced the neuritogenic effect of the myenteric plexus whereas the nitric oxide donor, sodium nitroprusside (SNP), partially reversed the blocking effect of TTX. 2-Chloroadenosine (2-CA), a stable analogue of adenosine, which is produced following release of ATP from enteric neurones, further enhanced the effect of SNP. Basic fibroblast growth factor or neurotrophin-3 in combination with 2-CA and SNP were only marginally neuritogenic in striatal cultures alone. These results suggest that NO is involved in the trophic effects of myenteric plexus explants on striatal neurones.