Cholinergic modulation of slow cortical rhythm in urethane-anesthetized rats

Attila Toth, Tunde Hajnik, Laszlo Detari

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Slow cortical rhythm (SCR) is characterized by rhythmic cycling of active (UP) and silent (DOWN) states in cortical cells. In urethane anesthesia, SCR appears as alternation of almost isoelectrical EEG periods and low-frequency, high-amplitude large shifts with superimposed high-frequency activity in the local field potentials (LFPs). Dense cholinergic projection reaches the cortex from the basal forebrain (BF), and acetylcholine (ACh) has been demonstrated to play a crucial role in the regulation of cortical activity. In the present experiments, cholinergic drugs were administered topically to the cortical surface of urethane-anesthetized rats to examine the direct involvement of ACh and the BF cholinergic system in the SCR.SCR was recorded by a 16-pole vertical electrode array from the hindlimb area of the somatosensory cortex. Multiple unit activity (MUA) was recorded from layer V to VI in close proximity of the recording array. Neither a low dose (10. mM solution) of the muscarinic antagonist atropine or the nicotinic agonist nicotine (1. mM solution) had any effect on SCR. In contrast, the higher dose (100. mM solution) of atropine, the cholinergic agonist carbachol (32. mM solution), and the cholinesterase inhibitor physostigmine (13. mM solution) all decreased the number of UP states, delta power (0-3. Hz) and MUA.These results suggest that cholinergic system may influence SCR through muscarinic mechanisms during urethane anesthesia. Cholinergic activation obstructs the mechanisms responsible for local or global synchronization seen during SCR as this rhythm was disrupted or aborted. Muscarinic antagonism can evoke similar changes when high dose of atropine is applied.

Original languageEnglish
Pages (from-to)117-129
Number of pages13
JournalBrain Research Bulletin
Volume87
Issue number1
DOIs
Publication statusPublished - Jan 4 2012

Keywords

  • Basal forebrain
  • Cholinergic drugs
  • Coherence
  • Field potential
  • Slow cortical rhythm
  • Somatosensory cortex

ASJC Scopus subject areas

  • Neuroscience(all)

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