Long-Term Modulation of A-Type K+ Conductances in Hippocampal CA1 Interneurons in Rats After Chronic Intermittent Ethanol Exposure During Adolescence or Adulthood
Version of Record online: 26 JUL 2013
Copyright © 2013 by the Research Society on Alcoholism
Alcoholism: Clinical and Experimental Research
Volume 37, Issue 12, pages 2074–2085, December 2013
How to Cite
Li, Q., Fleming, R. L., Acheson, S. K., Madison, R. D., Moore, S. D., Risher, M.-L., Wilson, W. A. and Swartzwelder, H. S. (2013), Long-Term Modulation of A-Type K+ Conductances in Hippocampal CA1 Interneurons in Rats After Chronic Intermittent Ethanol Exposure During Adolescence or Adulthood. Alcoholism: Clinical and Experimental Research, 37: 2074–2085. doi: 10.1111/acer.12204
- Issue online: 3 DEC 2013
- Version of Record online: 26 JUL 2013
- Manuscript Accepted: 29 APR 2013
- Manuscript Received: 25 MAR 2013
- National Institute of Alcoholism and Alcohol Abuse. Grant Number: U01-AA019925
- Biomedical Laboratory Research and Development Service of the Department of Veterans Affairs Office of Research and Development
- Chronic Intermittent Ethanol Exposure
Chronic alcohol use, especially exposure to alcohol during adolescence or young adulthood, is closely associated with cognitive deficits that may persist into adulthood. Therefore, it is essential to identify possible neuronal mechanisms underlying the observed deficits in learning and memory. Hippocampal interneurons play a pivotal role in regulating hippocampus-dependent learning and memory by exerting strong inhibition on excitatory pyramidal cells. The function of these interneurons is regulated not only by synaptic inputs from other types of neurons but is also precisely governed by their own intrinsic membrane ionic conductances. The voltage-gated A-type potassium current (IA) regulates the intrinsic membrane properties of neurons, and disruption of IA is responsible for many neuropathological processes including learning and memory deficits. Thus, it represents a previously unexplored cellular mechanism whereby chronic ethanol (EtOH) may alter hippocampal memory-related functioning.
Using whole-cell electrophysiological recording methods, we investigated the enduring effects of chronic intermittent ethanol (CIE) exposure during adolescence or adulthood on IA in rat CA1 interneurons.
We found that the mean peak amplitude of IA was significantly reduced after CIE in either adolescence or adulthood, but IA density was attenuated after CIE in adolescence but not after CIE in adulthood. In addition, the voltage-dependent steady-state activation and inactivation of IA were altered in interneurons after CIE.
These findings suggest that CIE can cause long-term changes in IA channels in interneurons and thus may alter their inhibitory influences on memory-related local hippocampal circuits, which could be, in turn, responsible for learning and memory impairments observed after chronic EtOH exposure.