Cholinergic and behavior‐dependent beta and gamma waves are coupled between olfactory bulb and hippocampus

Author:

Leung L. Stan12ORCID,Gill Ravnoor Singh2,Shen Bixia1,Chu Liangwei1

Affiliation:

1. Department of Physiology and Pharmacology University of Western Ontario London Ontario Canada

2. Graduate Program in Neuroscience University of Western Ontario London Ontario Canada

Abstract

AbstractOlfactory oscillations may enhance cognitive processing through coupling with beta (β, 15–30 Hz) and gamma (γ, 30–160 Hz) activity in the hippocampus (HPC). We hypothesize that coupling between olfactory bulb (OB) and HPC oscillations is increased by cholinergic activation in control rats and is reduced in kainic‐acid‐treated epileptic rats, a model of temporal lobe epilepsy. OB γ2 (63–100 Hz) power was higher during walking and immobility‐awake (IMM) compared to sleep, while γ1 (30–57 Hz) power was higher during grooming than other behavioral states. Muscarinic cholinergic agonist pilocarpine (25 mg/kg ip) with peripheral muscarinic blockade increased OB power and OB‐HPC coherence at β and γ1 frequency bands. A similar effect was found after physostigmine (0.5 mg/kg ip) but not scopolamine (10 mg/kg ip). Pilocarpine increased bicoherence and cross‐frequency coherence (CFC) between OB slow waves (SW, 1–5 Hz) and hippocampal β, γ1 and γ2 waves, with stronger coherence at CA1 alveus and CA3c than CA1 stratum radiatum. Bicoherence further revealed a nonlinear interaction of β waves in OB with β waves at the CA1‐alveus. Beta and γ1 waves in OB or HPC were segregated at one phase of the OB‐SW, opposite to the phase of γ2 and γ3 (100–160 Hz) waves, suggesting independent temporal processing of β/γ1 versus γ2/γ3 waves. At CA1 radiatum, kainic‐acid‐treated epileptic rats compared to control rats showed decreased theta power, theta‐β and theta‐γ2 CFC during baseline walking, decreased CFC of HPC SW with γ2 and γ3 waves during baseline IMM, and decreased coupling of OB SW with β and γ2 waves at CA1 alveus after pilocarpine. It is concluded that β and γ waves in the OB and HPC are modulated by a slow respiratory rhythm, in a cholinergic and behavior‐dependent manner, and OB‐HPC functional connectivity at β and γ frequencies may enhance cognitive functions.

Funder

Natural Sciences and Engineering Research Council of Canada

Publisher

Wiley

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3