@phdthesis{oai:tsukuba.repo.nii.ac.jp:00008722,
 author = {Naka, Takashi and 仲, 隆},
 month = {},
 note = {A Compartment model representing the chemical transmission process of acetylcholine (Ach) at the neuromuscular junction for generation of the miniature endplate current (MEPC) is constructed as a reaction-diffusion system (RD system) in a two-dimensional space of axissymetrical disc of the synaptic cleft. The model is defined as the standard to have the critical radius of 500nm and the respective compartment numbers of 3 and 10 on the transverse and radial coordinates. Besides the transverse and radial diffusion processes, the model can include the release mechanism of Ach as the release rate and the release area of Ach, and the junctional fold as a concentric cylinder attached to the disc at the postsynaptic membrane. The model might be regarded as the two-dimensional extension of the similar models proposed previously, which essentially behave as one-dimensional compartment models because the diffusion process in either of two direction is simplified.  This two-dimensional compartment model is effectively applied to analysis of the functional and structural correlations in the transmission process. The simulation analysis with the model demonstrates that the diffusion coefficient for isotropic diffusion in the disc is evaluated to be 1.0×10-6cm2sec-1, with which the model reproduces the behavior of the MEPC from the empirical analysis with respect to the characteristic parameters. It further follows that in the RD system with anisotropic diffusion the radial diffusion has more distinctive effects on the MEPC than the transverse diffusion. The neurotransmitter release mechanisms of the expanding pore and the acceleration release are examined to reveal that the expanding rate more than 10nm/msec and the acceleration rate 10 times of the natural diffusion with the diffusion coefficient around 1.0×10-6cm2sec-1 could reproduce the empirical MEPC. The effects of the junctional fold and the synaptic vesicle are further analyzed to elucidate their unknown functions associated with the specific structures at the neuromuscular junction. The width of the junctional fold has more distinctive effects than the depth in enlargement of the reaction area of the postsynaptic membrane. The quantal release mechanism raises significantly the amplitudes of MEPC and the endplate current (EPC). The localized release of Ach has the similar effect on EPC compared with the homogeneous release of Ach., 1997},
 school = {筑波大学, University of Tsukuba},
 title = {Estimation of functional and structural parameters in the chemical transmission process at the neuromuscular junction},
 year = {1998}
}