Patch clamp study of single glutamate channels during development in insect muscle

Abstract

The kinetics of glutamate receptor channels in larval and imaginal muscle of the insect Tenebrio molitor (mealworm) were studied by patch clamp recording. Single glutamate channels in the larval muscle had small conductance and long open time characteristics, whereas channels in the imaginal muscle had large conductances and short open times. The reciprocal of channel closed time was linearly related to the glutamate concentration in imaginal muscle; channels in larval muscle, however, showed only a weak dependence on the glutamate concentration. In the study of agonist-induced channels, quisqualate and kainate opened channels with conductances similar to those opened by glutamate. Compared to glutamate, however, the mean open time was longer for quisqualate and shorter for kainate. The results suggest that the glutamate receptor-ion channel complex in insect muscles changes its properties during metamorphosis.