Glutamine as precursor for the GABA and glutamate trasmitter pools.

Pigeon optic tectum slices were incubated in [(3)H] glutamine in order to label the glutamate and GABA pools. 47 mM potassium chloride induced a calcium-dependent release of [(3)H] glutamate and [(3)H] GABA. This indicates that glutamine is an efficient precursor of the releasable glutamate and GABA pools and supports the view that both amino acids play a role as neurotransmitters in the optic tectum.