Pharmacology, Cloning and Expression of Insect Nicotinic Acetylcholine Receptors

There is considerable evidence that acetylcholine is an excitatory neurotransmitter at many synapses in the insect central nervous system (Sattelle 1986). Despite the acute technical difficulties of proving that a putative transmitter exerts a functional role at a particular synapse, detailed studies on the antennal (olfactory) afferent input to the antennal lobes of the moth Manduca sexta (Sanes and Hildebrand 1976 a,b; Sanes et al 1977) and the cercal (mechanosensory) afferent input to the giant interganglionic interneurons of the abdominal ganglion of the cockroach Periplaneta americana (Callec 1974; Sattelle 1980) have in each case fulfilled many of the required criteria (cf. Gerschenfeld 1973), leading to the hypothesis that acetylcholine is a major sensory neurotransmitter in the insect central nervous system (CNS).