Department of Molecular Cell Biology, Laboratory of Neurophysiology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
Department of Molecular Cell Biology, Laboratory of Neurophysiology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
Proc Natl Acad Sci U S A. 2014 Jul 1;111(26):9627-32. doi: 10.1073/pnas.1319820111. Epub 2014 Jun 16.
The balance between excitation and inhibition is essential for the proper function of neuronal networks in the brain. The inhibitory neurotransmitter γ-aminobutyric acid (GABA) contributes to the network dynamics within the suprachiasmatic nucleus (SCN), which is involved in seasonal encoding. We investigated GABAergic activity and observed mainly inhibitory action in SCN neurons of mice exposed to a short-day photoperiod. Remarkably, the GABAergic activity in a long-day photoperiod shifts from inhibition toward excitation. The mechanistic basis for this appears to be a change in the equilibrium potential of GABA-evoked current. These results emphasize that environmental conditions can have substantial effects on the function of a key neurotransmitter in the central nervous system.
兴奋与抑制之间的平衡对于大脑神经元网络的正常功能至关重要。抑制性神经递质γ-氨基丁酸（GABA）有助于视交叉上核（SCN）内的网络动态，该核参与季节编码。我们研究了 GABA 能活性，并观察到在短日光照周期下暴露的小鼠的 SCN 神经元中主要表现为抑制作用。值得注意的是，在长日光照周期下，GABA 能活性从抑制转向兴奋。这种现象的机制基础似乎是 GABA 诱发电流的平衡电位发生了变化。这些结果强调了环境条件对中枢神经系统中关键神经递质功能的重大影响。
