LOCALIZATION OF SYNAPTIC INPUT ON DENDRITES OF A LAMPREY SPINAL-CORD NEURON FROM PHYSIOLOGICAL MEASUREMENTS OF MEMBRANE-PROPERTIES
LOCALIZATION OF SYNAPTIC INPUT ON DENDRITES OF A LAMPREY SPINAL-CORD NEURON FROM PHYSIOLOGICAL MEASUREMENTS OF MEMBRANE-PROPERTIES
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DOI：
10.1113/jphysiol.1979.sp013042
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发表时间：
1979-01-01
影响因子：
5.5
通讯作者：
TEUBL, WP
中科院分区：
文献类型：
--
作者：
CHRISTENSEN, BN;TEUBL, WP
复合兴奋性突触后电位（EPSP）引起的电紧张性和化学突触连接记录从18个中间神经元刺激后的I2爆发轴突在离体七鳃鳗脊髓。在每个细胞中，电紧张性EPSP的半宽度被测量，并与电缆参数估计为同一个神经元一起使用，以定位由I2轴突在中间神经元的树突上的突触接触的位置。突触的位置范围为0.05-1.35空间常数，平均为0.46。使用神经元的Rall模型模拟突触电位。与实验记录的具有相同半宽的EPSP相比，模拟的突触电位上升时间更快。通过改变突触距离和/或突触电流时程，模拟的突触电位的半宽、上升时间和衰减与实验的EPSP非常吻合。从模拟估计的突触距离的范围大大减少（0.2-0.7空间常数，平均0.52）。直接比较的突触位置估计的树突状树从这些相同的细胞注射辣根过氧化物酶的组织学示踪相比，有利的突触位置估计的模拟。功能相似的突触前轴突，使突触连接在相同的电紧张距离的索马上功能相似的突触后细胞提出。这发生在面对这些相同的突触接触的物理距离的巨大变化时。
Composite excitatory post-synaptic potentials (EPSP) resulting from electrotonic and chemical synaptic junctions were recorded from 18 interneurons following stimulation of the I2 burster axon in the isolated lamprey spinal cord. In each cell, the half-width of the electrotonic EPSP was measured and used, together with the cable parameters estimated for the same neuron, to locate the position of synaptic contact made by the I2 axon on the dendrites of the interneuron. The synaptic location ranged from 0.05-1.35 space constants, with a mean of 0.46. The synaptic potential was simulated using the Rall model of the neuron. When compared with the experimentally recorded EPSP with the same half-width, the rise-time of the simulated synaptic potential was faster. By changing the value of synaptic distance and/or synaptic current duration, the half-width, rise-time and decay of the simulated synaptic potential fit closely the experimental EPSP. The range of synaptic distance estimated from the simulation decreased considerably (0.2-0.7 space constants; mean 0.52). Direct comparison of synaptic location estimated from histological tracings of dendritic trees from these same cells injected with horseradish peroxidase compared favorably with synaptic location estimated from the simulations. Functionally similar presynaptic axons that make synaptic connections at the same electrotonic distance from the soma on functionally similar post-synaptic cells is proposed. This occurs in the face of large variations in physical distance for these same synaptic contacts.