2017 Fiscal Year Research-status Report

難治性下部尿路機能障害に対する光遺伝学による新たな治療法の開発に関する研究

Research Project

Project/Area Number	17K16785
Research Institution	University of Yamanashi
Principal Investigator	志村寛史山梨大学, 大学院総合研究部, 医学研究員 (70755842)
Project Period (FY)	2017-04-01 – 2019-03-31
Keywords	micturition / acc / optogenetics / electrical stimulation
Outline of Annual Research Achievements	We found that bilateral electrical stimulation of the ACC on MIT gradually reduced MIT. Next, the bilateral ACC of Thy1-channelrhodopsin2(ChR2)-EFYP mouse, in which deep layer pyramidal neurons express ChR2, was optogenetically activated. Optical stimulation (5 ms pulses at 50 Hz for 60 s duration) consistently increased bladder pressure with the latency and the peak time of 6.7 s and 30.2 s after the stimulation, respectively (N=3 mice). These results indicate that activation of the ACC outputs induces micturition. Our results demonstrated the novel role of the ACC in the regulation of micturition; the ACC is not only involved in the filling phase but also in the voiding phase. Further selective manipulation of neuronal activity in the ACC may precisely regulate micturition process.
Current Status of Research Progress	Current Status of Research Progress 2: Research has progressed on the whole more than it was originally planned. Reason 1.The contribution of the ACC to the MIT by lesion experiments. MIT was shortened by either the electrode insertion or electrical lesion. 2.We injected muscimol (GABA agonist) into bilateral ACC in wild type mice (N =6). After injection, MIT became significantly longer than that of pre-injection. 3.We employed optogenetic stimulation of ACC neurons in order to further investigate the causal relationship between the activity of ACC neurons and micturition. Photoactivation of excitatory layer 5 pyramidal neurons in the ACC reliably induced micturition (N=3). Photoactivation of parvalbumin(PV) positive inhibitory interneurons significantly prolonged the MIT. We used PV-Cre mouse which was injected adeno-associated virus of Cre-inducible ChR2-expression into bilateral ACC(N=6).
Strategy for Future Research Activity	Our results suggest that the ACC plays a crucial role for the control of micturition and that the balance of excitation and inhibition in the ACC may regulate micturition.