Physical Release of Acetylcholine from the Thoracic Nerve Cord of Periplaneta americana L

RECENTLY, suggestions have been made that acetylcholine in nerve tissue is associated with structural entities termed ‘vesicles’ 1 . The ideas are compatible with a quantum concept of nerve transmission 2 . The evidence that acetylcholine is released from mammalian nerve tissue by physical means 3 lends further support to the structural inclusion of acetylcholine within the nerve cell and casts doubt on the hypothesis that it is held in chemical combination. The following results on the release of acetylcholine from cockroach thoracic cord by osmotic pressure and homogenization makes the existence of a chemical combination in insects doubtful.