EXCITATORY SYNAPTIC POTENTIALS IN NEURONS OF THE DEEP NUCLEI IN OLIVOCEREBELLAR SLICE CULTURES
EXCITATORY SYNAPTIC POTENTIALS IN NEURONS OF THE DEEP NUCLEI IN OLIVOCEREBELLAR SLICE CULTURES
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DOI：
10.1016/0306-4522(92)90366-a
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发表时间：
1992-08-01
期刊：
影响因子：
3.3
通讯作者：
KNOPFEL, T
中科院分区：
文献类型：
--
作者：
AUDINAT, E;GAHWILER, BH;KNOPFEL, T
用细胞内记录的方法研究了电刺激小脑片培养的大鼠小脑深核神经元和电刺激橄榄-小脑联合培养的橄榄外植体诱发的兴奋性突触后电位。在小脑深层核团的神经元中，刺激核组织和刺激橄榄组织都会引起兴奋性突触后电位的快速上升，然后是抑制性突触后电位和长时间的兴奋。6-氰基-7-硝基-2，3-二酮可阻断快速上升的兴奋性突触后电位和随后的抑制性突触后电位。剩余的去极化被D-(-)-2-氨基-5-磷酸-戊酸所消除，表明该电位是由N-甲基-D-天冬氨酸受体介导的。加入D-(-)-2-氨基-5-磷酸戊酸可抑制慢兴奋，但不影响快兴奋性和抑制性突触后电位。在荷包牡丹碱存在下，刺激橄榄组织所诱发的6-氰基-7-硝基-2，3-二酮和D-(-)-2-氨基-5-磷酸戊酸敏感的兴奋性突触后电位具有相同的潜伏期，并随刺激强度的不同而不同。D-(-)-2-氨基-5-磷酸戊酸敏感型兴奋性突触后电位的达峰时间和持续时间明显长于6-cyano-7-nitroquinoxaline-2，3-dione-sensitive兴奋性突触后电位。在含镁溶液中，随着膜超极化，6-cyano-7-nitroquinoxaline-2，3-dione-sensitive兴奋性突触后电位的幅度增大，而D-(-)-2-氨基-5-磷酸戊酸敏感的兴奋性突触后电位的幅度降低。从浴液中去除镁导致N-甲基-D-天冬氨酸受体介导的兴奋性突触后电位增加，其幅度随膜超极化而增加。同一切片培养中的Purkinje细胞的记录显示，6-氰基-7-硝基喹恶啉-2，3-二酮可逆地取消刺激小脑皮质内诱发的分级兴奋性突触后电位以及刺激橄榄组织诱导的全部或全部不引起爬行纤维反应。此外，D-(-)-2-氨基-5-磷酸戊酸不影响这些突触反应，即使在无镁的浴液中也是如此。
Excitatory postsynaptic potentials evoked in neurons of the deep cerebellar nuclei, either by electrical stimulation within the nuclei in cerebellar slice cultures or by electrical stimulation of olivary explants in olivo-cerebellar co-cultures, were investigated in the rat by means of intracellular recordings. In neurons of the deep cerebellar nuclei, stimulation of the nuclear tissue, as well as stimulation of the olivary tissue, induced a fast rising excitatory postsynaptic potential, followed by an inhibitory postsynaptic potential and a long-lasting excitation. The fast rising excitatory postsynaptic potential and the following inhibitory postsynaptic potential were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione. The remaining depolarization was abolished by D-( - )-2-amino-5-phosphonovalerate, suggesting that this potential was mediated by N-methyl-D-aspartate receptors. With only D-( - )-2-amino-5-phosphonovalerate added to the bath, the slow excitation was depressed, whereas the fast excitatory and inhibitory postsynaptic potentials were not affected. In the presence of bicuculline, the 6-cyano-7-nitroquinoxaline-2,3-dione-and the D-( - )-2-amino-5-phosphonovalerate-sensitive excitatory postsynaptic potentials elicited by stimulation of the olivary tissue had the same latency, and were both graded with stimulation strength. The time-to-peak and the duration of the D-( - )-2-amino-5-phosphonovalerate-sensitive excitatory postsynaptic potentials were considerably longer than those of the 6-cyano-7-nitroquinoxaline-2,3-dione-sensitive excitatory postsynaptic potentials. In magnesium-containing bathing solution, the amplitude of the 6-cyano-7-nitroquinoxaline-2,3-dione-sensitive excitatory postsynaptic potentials increased, while the amplitude of the D-( - )-2-amino-5-phosphonovalerate-sensitive excitatory postsynaptic potentials decreased with membrane hyperpolarization. Removal of magnesium from the bathing solution resulted in an increase in N-methyl-D-aspartate receptor-mediated excitatory postsynaptic potentials whose amplitude increased with membrane hyperpolarization.Recordings from Purkinje cells within the same slice cultures revealed that 6-cyano-7-nitroquinoxaline-2,3-dione reversibly abolished graded excitatory postsynaptic potentials induced by stimulation within the cerebellar cortex as well as all-or-none climbing fibre responses induced by stimulation of the olivary tissue. Furthermore, D-( - )-2-amino-5-phosphonovalerate did not affect these synaptic responses, even in magnesium-free bathing solution.