کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4496912 1623921 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synaptic glutamate spillover increases NMDA receptor reliability at the cerebellar glomerulus
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم کشاورزی و بیولوژیک (عمومی)
پیش نمایش صفحه اول مقاله
Synaptic glutamate spillover increases NMDA receptor reliability at the cerebellar glomerulus
چکیده انگلیسی

Glutamate spillover in the mossy fiber to granule cell cerebellar glomeruli has been hypothesized to increase neurotransmission reliability. In this study, we evaluate this hypothesis using an experimentally based quantitative model of glutamate spillover on the N-methyl-d-aspartate receptors (NMDA-Rs) at the cerebellar glomerulus. The transient and steady-state responses of NMDA-Rs were examined over a physiological range of firing rates. Examined cases included direct glutamate release activation, glutamate spillover activation, and a combination of direct and spillover activation. Our results illustrate that the effects of spillover alone are equivalent to direct release and, notably, combined spillover and direct release effects on NMDA-Rs are not additive. Our results show that spillover does in fact provide a high degree of reliability given that the synaptic vesicle release rate must fall to approximately 15–25% of what is considered the normal baseline level in order to substantially alter neurotransmission across the examined range of frequencies. We suggest that the high reliability provided by activation due to glutamate spillover could be used to conserve energy by reducing the required overall glutamate load at higher frequencies.


► Spillover activation of glomerulus NMDA-Rs is nearly equivalent to direct release.
► Vesicle release rates must fall 15–25% to substantially alter neurotransmission.
► Spillover could be used to conserve energy by reducing glutamate load.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Theoretical Biology - Volume 289, 21 November 2011, Pages 217–224
نویسندگان
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