Sa. Petersen et al., GENETIC-ANALYSIS OF GLUTAMATE RECEPTORS IN DROSOPHILA REVEALS A RETROGRADE SIGNAL REGULATING PRESYNAPTIC TRANSMITTER RELEASE, Neuron, 19(6), 1997, pp. 1237-1248
Postsynaptic sensitivity to glutamate was genetically manipulated at t
he Drosophila neuromuscularjunction (NMJ) to test whether postsynaptic
activity can regulate presynaptic function during development. We clo
ned the gene encoding a second muscle-specific glutamate receptor, DGl
uRIIB, which is closely related to the previously identified DGluRIIA
and located adjacent to it in the genome. Mutations that eliminate DGl
uRIIA (but not DGluRIIB) or transgenic constructs that increase DGluRI
IA expression were generated. When DGluRIIA is missing, the response o
f the muscle to a single vesicle of transmitter is substantially decre
ased.;However, the response of the muscle to nerve stimulation is norm
al because quantal content is significantly increased. Thus, a decreas
e in postsynaptic receptors leads to an increase in presynaptic transm
itter release, indicating that postsynaptic activity controls a retrog
rade signal that regulates presynaptic function.