Adrenergic receptor-mediated modulation of striatal firing patterns

作者：Ohta Hiroyuki^*; Kohno Yu; Arake Masashi; Tamura Risa; Yukawa Suguru; Sato Yoshiaki; Morimoto Yuji; Nishida Yasuhiro; Yawo Hiromu

来源：Neuroscience Research, 2016, 112: 47-56.

DOI：10.1016/j.neures.2016.05.004

• Striatum
• Noradrenaline
• Beta adrenergic receptor
• Alphal adrenergic receptor

Although noradrenaline and adrenaline are some of the most important neurotransmitters in the central nervous system, the effects of noradrenergic/adrenergic modulation on the striatum have not been determined. In order to explore the effects of adrenergic receptor (AR) agonists on the striatal firing patterns, we used optogenetic methods which can induce continuous firings. We employed transgenic rats expressing channelrhodopsin-2 (ChR2) in neurons. The medium spiny neuron showed a slow rising depolarization during the 1-s long optogenetic striatal photostimulation and a residual potential with 8.6-s half-life decay after the photostimulation. As a result of the residual potential, five repetitive 1 sec long photostimulations with 20-s onset intervals cumulatively increased the number of spikes. This 'firing increment', possibly relating to the timing control function of the striatum, was used to evaluate the AR modulation. The p -AR agonist isoproterenol decreased the firing increment between the 1st and 5th stimulation cycles, while the alpha(1)-AR agonist phenylephrine enhanced the firing increment. Isoproterenol and adrenaline increased the early phase (0-0.5 s of the photostimulation) firing response. This adrenergic modulation was inhibited by the beta-antagonist propranolol. Conversely, phenylephrine and noradrenaline reduced the early phase response. beta-ARs and alpha(1)-ARs work in opposition controlling the striatal firing initiation and the firing increment.

• 出版日期2016-11