title: Phase-Dependent Modulation of Oscillatory Phase and Synchrony by Long-Lasting Depolarizing Inputs in Central Neurons.
abstract: Oscillatory neural activities have been implicated in various types of information processing in the CNS. The procerebral (PC) lobe of the land molluskLimax valentianusshows an ongoing oscillatory local field potential (LFP). Olfactory input increases both the frequency and spatial synchrony of the LFP oscillation by a nitric oxide (NO)-mediated mechanism, but how NO modulates the activity in a specific manner has been unclear. In the present study, we used electrical stimulation and NO uncaging to systematically analyze the response of the LFP oscillation and found phase-dependent effects on phase shifting and synchrony. The neurons that presumably release NO in the PC lobe preferentially fired at phases in which NO has a synchronizing effect, suggesting that the timing of NO release is regulated to induce a stereotyped response to natural sensory stimuli. The phase-response curve (PRC) describes the timing dependence of responses of an oscillatory system to external input. PRCs are usually constructed by recording the temporal shifts of the neural activity in response to brief electrical pulses. However, NO evokes a long-lasting depolarization persisting for several cycles of oscillation. The phase-response relationship obtained by NO stimulation was approximately the integral of the PRC. A similar relationship was also shown for regular firing of mouse cerebellar Purkinje cells receiving step depolarization, suggesting the generality of the results to oscillatory neural systems with highly distinct properties. These results indicate novel dynamic effects of long-lasting inputs on network oscillation and synchrony, which are based on simple and ubiquitous mechanisms.
authors: Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan.
authors: Satoshi
authors: 0000-0001-9821-7598
authors: S
authors: Watanabe
authors: Graduate School of Brain Science, Doshisha University , Kyoto 610-0394, Japan.
authors: Moritoshi
authors: 0000-0001-6068-1045
authors: M
authors: Hirono
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000502:physiology; D004558:Electric Stimulation; D017952:Ganglia, Invertebrate / Q000502:physiology; D049851:Gastropoda; D008564:Membrane Potentials / Q000502:physiology*; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010507:Periodicity; D046509:Tissue Culture Techniques
chemical_list: D009569:Nitric Oxide
keywords: Purkinje cell; neural oscillation; olfactory processing; phase–response curve; synchronization