ENHANCEMENT OF SYNAPTIC TRANSMISSION BY 4-AMINOPYRIDINE IN HIPPOCAMPAL SLICES OF THE RAT
ENHANCEMENT OF SYNAPTIC TRANSMISSION BY 4-AMINOPYRIDINE IN HIPPOCAMPAL SLICES OF THE RAT
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DOI：
10.1113/jphysiol.1982.sp014180
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发表时间：
1982-01-01
影响因子：
5.5
通讯作者：
HAAS, HL
中科院分区：
文献类型：
--
作者：
BUCKLE, PJ;HAAS, HL
体外研究了4-氨基吡啶（4-AP）对大鼠海马神经传递的影响。从CA1海马神经元的体区和树突区获得了场电位的胞外记录和兴奋性和抑制性突触后电位、动作电位和TTX[河豚毒素]抗性峰的胞内记录。持续灌注或大剂量注射微摩尔浓度的4-AP可导致突触场电位和种群峰值的振幅持续增强，而传入输入没有改变。局部微施4-AP后，体正波（p波）增加。细胞内记录显示兴奋性突触后电位和抑制性突触后电位的振幅增加。ipsp延长4-AP。锥体细胞在初始超极化后，在暴露于4-AP期间去极化高达10 mV。膜电导变化不一致。膜电位的自发位移表现为巨大的e.p.s.p和i.p.s.p，自发性i.p.s.p的频率和幅度均有所增加。4-AP降低了e.p.s.p.的成对脉冲促进，提示突触前调节了递质输出。4-AP明显增强海马兴奋性突触和抑制性突触的递质释放。
The effects of 4-aminopyridine (4-AP) on neurotransmission in hippocampal slices of the rat were studied in vitro. Extracellular recordings of field potentials and intracellular recordings of excitatory and inhibitory postsynaptic potentials, action potentials and TTX[tetrodotoxin]-resistant spikes were obtained from the somatic and dendritic fields of CA1 hippocampal neurons. Constant perfusion with, or bolus injection of, 4-AP in micromolar concentrations resulted in substantial and persistent enhancement of the amplitude of synaptic field potentials and population spikes, with no alteration of the afferent input. Somatic positive waves (p-waves) were increased after local micro-application of 4-AP. Intracellular recordings revealed an increase in the amplitude of e.p.s.p. [excitatory postsynaptic potential] and i.p.s.p. [inhibitory postsynaptic potential]. I.p.s.p. were prolonged by 4-AP. The pyramidal cells were, after an initial hyperpolarization, depolarized by up to 10 mV during exposure to 4-AP. The membrane conductance was not consistently changed. Spontaneous shifts of the membrane potential were described as giant e.p.s.p. and i.p.s.p. Spontaneous i.p.s.p. were increased in frequency and amplitude. Paired-pulse facilitation of e.p.s.p. was reduced by 4-AP, suggesting a presynaptic modulation of transmitter output. 4-AP evidently enhances transmitter release at both excitatory and inhibitory synapses in the hippocampus.