Berry M S, Pentreath V W
J Exp Biol. 1975 Jun;62(3):797-803. doi: 10.1242/jeb.62.3.797.
Several investigators of the molluscan nervous system have used TEA, injected into presynptic neurones, to determine whether the connexions made by these neurones are monosynaptic. The increase in spike duration produced by the TEA causes an increase in transmitter release, and hence an increase in the amplitude of the postsynaptic potential if the connexion is direct. If the connexion is indirect, the spike in an intercalated neurone will not be affected by the TEA, and the postsynaptic response will remain constant. Experiments described here show that TEA can cross electrotonic junctions in the gastropod mollusc Planorbis corneus. They also show that each TEA-prolonged presynaptic impulse may produce more than one postsynaptic impulse. A larger postsynaptic potential could therefore be produced by presynaptic injection of TEA in the case of an indirect connexion. This indicates that care must be taken when interpreting the results of experiments using TEA to test for monosynaptic connexions.
几位研究软体动物神经系统的人员已将四乙铵注入突触前神经元，以确定这些神经元形成的连接是否为单突触连接。四乙铵导致的动作电位时程增加会使递质释放增加，因此，如果连接是直接的，突触后电位的幅度就会增加。如果连接是间接的，插入神经元的动作电位将不受四乙铵影响，突触后反应将保持不变。此处所述的实验表明，四乙铵可穿过腹足纲软体动物角平螺的电突触。实验还表明，每个经四乙铵延长的突触前冲动可能会产生不止一个突触后冲动。因此，在间接连接的情况下，通过突触前注入四乙铵可能会产生更大的突触后电位。这表明在解释使用四乙铵测试单突触连接的实验结果时必须谨慎。
