AMINO ACID NEUROTRANSMITTERS

摘要

L-glutamic acid (Glu) and γ-aminobutyric acid (GABA) are the transmitters at skeletal nerve-muscle junctions in insects (Piek, 1985a) and probably also serve important transmitter roles in the central nervous systems of insects (Pitman, 1985). The distributions of these transmitters and their receptors in the insect nervous system will be described and the division of Glu and GABA receptors in sub-classes based upon pharmacological and biochemical findings will be discussed. Recent developments in the use of toxins from wasp (Piek, 1985b) and spider (Usherwood, 1985) venoms to block transmission at peripheral Glu synapses may provide useful leads for the chemical industry in its search for novel pesticides. The experimental evidence which has lead to these developments will be presented together with preliminary information on the chemistry of the toxins. Single channel analysis has given major insight into the biophysical properties of insect Glu and GABA receptors. An account will be given of some of this work and the manner in which it has clarified views of agonist potency, receptor channel kinetics, and channel blocking.