0000000000883840
AUTHOR
V. P. Whittaker
Thirty years of synaptosome research.
Detached synapses (synaptosomes), first isolated by the author in 1958 and identified as such in 1960, are sealed presynaptic nerve terminals often with a portion of the target cell--sometimes amounting to a complete dendritic spine--adhering to their external surface. They can be prepared in high yield from brain tissue and also in decreasing yield from spinal cord, retina, sympathetic ganglia, myenteric plexus and electric organs. They are sealed structures which, under metabolizing conditions, respire, take up oxygen and glucose, extrude Na+, accumulate K+, maintain a normal membrane potential and, on depolarization, release transmitter in a Ca(2+)-dependent manner. They thus provide an …
Recent progress in understanding cholinergic function at the cellular and molecular levels
Cholinergic transmission can claim to be the first form of chemical neurotransmission to be investigated by pharmacological and electrophysiological methods and the first in which both the transmitter and its receptor have been isolated and characterized. One reason for this is that neuromuscular transmission is cholinergic and the neuromuscular junction (especially that of frogs) is a readily investigated synapse in which responses are recorded by a muscular twitch — something which can be appreciated by direct observation and which does not require sophisticated equipment. Another is that in the form of the electric organs of strongly electric fish Nature has provided a tissue embryologic…