Acetylcholine as an excitatory neuromuscular transmitter in the stomatogastric system of the lobster

Abstract

THERE is much physiological evidence that L-glutamate acts as an excitatory transmitter at many arthropod neuromuscular synapses1-3. The only suggestion that acetylcholine (ACh) has such a function is due to Futamachi 4. He showed that the nerve terminal region innervated by the largest crayfish slow flexor excitatory motor neurone is depolarised by iontophoretic applications of ACh, but not L-glutamate. I now have biochemical and physiological evidence that ACh is the neurotransmitter at some, but not all, of the excitatory neuromuscular synapses of the lobster stomatogastric system. © 1974 Nature Publishing Group.