The inhibitory action of L-glutamic acid esters on the insect neuromuscular junction

1. γ-Methyl and γ-ethyl esters of L-glutamic acid in 10 mM concentration blocked the mealworm larval neuromuscular transmission while diesters of L-glutamic acid were less effective. 2. The amplitude of the intra- and extracellular EPSPs was reduced by the treatment of 10 mM γ-esters in a few minutes. 3. The result suggest that the glutamte receptor in insect muscles resembles to that of the crayfish muscle and differs to some degree from the glutamate receptor on mammalian central neurones.