2004 Fiscal Year Final Research Report Summary
New Neurophysiological functions of taurine
| Project/Area Number |
14360071
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
食品科学・栄養科学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HISATSUNE Tatsuhiro The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 大学院・新領域創成科学研究科, 助教授 (10238298)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Taurine / Amino acid / Development / Mammals / Glycine receptors / GABA receptors / Physiology |
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| Research Abstract |
Taurine (2-aminoethanesulfonic acid) is the most abundant free amino acid in the developing mammalian cerebral cortex ; however few studies have reported its neurobiological functions during development. In this study, by means of whole-cell patch-clamp recordings, we examined the effects of taurine on chloride channel receptors in neocortical neurons from early to late postnatal stages, which cover a critical period in cortical circuit formation. We show here that taurine activates chloride channels in cortical neurons throughout the postnatal stages examined (from postnatal day 2 to day 36). The physiological effects of taurine changed from excitatory to inhibitory due to variations in the intracellular Cl^- concentration during development. An antagonist blocking analysis also demonstrated a developmental shift in the receptor target of taurine, from glycine receptors to GABA_A receptors. Taken together, these results may reflect genetically programmed, bidirectional functions of taurine. At the early developmental stage, taurine acting on glycine receptors would serve to promote cortical circuit formation. As the target for taurine shifts to the GABA_A receptor, taurine would assume an alternative function as a neuroprotector of developing neural circuitry, which tends to be hyperactive during development.
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