ROLE OF GLUTAMATE IN THE REGULATION OF THE OUTGROWTH AND MOTILITY OF NEURITES FROM MOUSE SPINAL-CORD NEURONS IN CULTURE

The excitatory amino acid glutamate has been shown to be toxic to a nu mber of neuronal cell types both in vitro and in vivo. It has also bee n shown to be capable of controlling the development of neurons grown in vitro. Using time-lapse video microscopy techniques the effects of glutamate on the rate of neurite outgrowth and growth cone motility we re examined on cultured mouse spinal cord neurons, Concentrations in t he range of 1 to 100 mu M caused a significant inhibition of neurite o utgrowth and concentrations of 10 and 100 mu M significantly inhibited growth cone activity. In addition it was shown that the kainate/AMPA receptor antagonist -)3-(2-carbvoxypiperazin-4-yl)-propyl-1-phosphonic acid, but not the NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3 -dione, was capable of blocking the inhibitory actions of glutamate on both outgrowth and motility. These results show that, at least in the culture system employed, glutamate might have a role in regulating ne uronal development and function.