Dan Y, Song H J, Poo M M
Department of Biological Sciences, Columbia University, New York, New York 10027.
Neuron. 1994 Oct;13(4):909-17. doi: 10.1016/0896-6273(94)90256-9.
The ability of differentiated neurons to secrete false transmitters in response to depolarization was examined by loading exogenous transmitters into the neuronal cytoplasm with a whole-cell recording pipette. We found that within minutes following loading of exogenous glutamate into the cytoplasm of cholinergic Xenopus spinal neurons, depolarization-evoked glutamate secretion could be detected by an acutely dissociated hippocampal pyramidal neuron manipulated into contact with the spinal neuron. Similarly, when ACh was loaded into a glutamatergic hippocampal neuron, evoked ACh secretion could be detected by a myocyte. The evoked secretion of the false transmitter was Ca2+ dependent and appeared to be vesicular in nature. These results suggest that differentiated neurons are capable of packaging and secreting multiple nonpeptide transmitters, provided that sufficient concentrations of the transmitters are available in the cytoplasm.
通过用全细胞记录移液管将外源性递质加载到神经元细胞质中，研究了分化神经元在去极化时分泌假递质的能力。我们发现，在将外源性谷氨酸加载到胆碱能非洲爪蟾脊髓神经元的细胞质中几分钟内，与脊髓神经元接触的急性分离海马锥体神经元就能检测到去极化诱发的谷氨酸分泌。同样，当乙酰胆碱加载到谷氨酸能海马神经元中时，心肌细胞就能检测到诱发的乙酰胆碱分泌。假递质的诱发分泌依赖于Ca2+，并且似乎本质上是囊泡性的。这些结果表明，只要细胞质中有足够浓度的递质，分化神经元就能够包装和分泌多种非肽类递质。
