Missing proof of cooperative synthesis of dopamine by non-dopaminergic neurons.

L-DOPA accumulation in the extracellular medium was detected when the transfer of L-DOPA from the neurons containing tyrosine hydroxylase to the neurons containing aromatic L-amino acid decarboxylase was blocked, under conditions of inhibition of the L-DOPA degradation enzyme. Thus, the missing proof confirming the existence of cooperative synthesis of dopamine by neurons non-dopaminergic was obtained.