Project/Area Number |
17500272
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Neurophysiology and muscle physiology
|
Research Institution | Tokyo Medical and Dental University |
Principal Investigator |
SATO Katsushige Tokyo Medical and Dental University, Graduate School, Lecturer, 大学院医歯学総合研究科, 講師 (80291342)
|
Co-Investigator(Kenkyū-buntansha) |
SATO Yoko (MOMOSE Yoko) Tokyo Medical and Dental University, Graduate School, Lecturer, 大学院医歯学総合研究科, 講師 (70251501)
|
Project Period (FY) |
2005 – 2006
|
Project Status |
Completed (Fiscal Year 2006)
|
Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
Keywords | optical recording / voltage-sensitive dye / central nervous system / functiogenesis / rat embryo / chick embryo / NTS / living stain |
Research Abstract |
Multiple-site optical recording with a fast voltage-sensitive dye, absorption dye NK2761, was used to study the developmental organization of functional synaptic networks in the vagal pathway. Glutamatergic excitatory postsynaptic potentials (EPSPs) evoked by vagus nerve stimulation was first detected from the nucleus of the tractus solitarius (NTS) at embryonic day 7 (E7) in chick embryos and E15 in rat embryos, when morphological differentiation of pre- and postsynaptic neurons is incomplete. When extracellular Mg^<2+> removed, small EPSPs were elicited at E6 in chick embryos and E14 in rat embryos. These results suggest that synaptic function mediated by N-methyl-D-aspartate (NMDA) receptors is latently generated one day before the expression of glutamatergic EPSP. Functional synapses related to the glossophyaryngeal nerve appear to be generated at the same time as the vagus nerve, but their spatial distribution was different from that of the vagus nerve. We further investigated the development of second synaptic pathways from the NTS to higher centers, and found that neuronal circuits from the NTS are already generated when the primary afferents form functional synapses with NTS neurons.
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