Taraskevich P S, Gibbs D, Schmued L, Orkand R K
J Neurobiol. 1977 Jul;8(4):325-35. doi: 10.1002/neu.480080405.
The anterior extrinsic protractors in the buccal mass of Aplysia are symmetrical sheets of branching bundles of muscle fibers which form an electrical syncytium. The addition of potassium or cholinergic, adrenergic, and glutaminergic agonists to the sea water bathing medium produces contracture of the muscle. Strychnine and cholinergic or adrenergic antagonists all block contractures produced by cholinergic and adrenergic agonists but not those produced by potassium or glutamate. Iontophoretic application through microelectrodes of acetylcholine or dopamine anywhere on the muscle surface produced a graded depolarization of the membrane. By contrast, glutamate produces depolarization only at discrete membrane sites. Endogeneous contractions often appeared spontaneously or could be induced by drug exposure. ATP inhibits endogeneous contractions.
海兔口球中的前外侧外在伸展肌是由分支的肌纤维束构成的对称薄片，形成一个电融合细胞。向浸泡海兔的海水介质中添加钾离子或胆碱能、肾上腺素能和谷氨酸能激动剂会导致肌肉挛缩。士的宁以及胆碱能或肾上腺素能拮抗剂均可阻断胆碱能和肾上腺素能激动剂引起的挛缩，但不能阻断钾离子或谷氨酸引起的挛缩。通过微电极在肌肉表面任何部位进行离子电渗施加乙酰胆碱或多巴胺，会使膜产生分级去极化。相比之下，谷氨酸仅在离散的膜位点产生去极化。内源性收缩常自发出现，或可由药物暴露诱导产生。ATP可抑制内源性收缩。
