Electric stimulation of the ears ameliorated learning and memory impairment in rats with cerebral ischemia-reperfusion injury

Sci Rep. 2016 Feb 5;6:20381. doi: 10.1038/srep20381.

Abstract

Ear acupuncture enhances the secretion of acetylcholine, which has anti-inflammatory effects. Here we want to investigate the effect of electric stimulation (ES) of the ears on learning and memory impairment in rats with cerebral ischemia-reperfusion injury. At 24 h after reperfusion, 2-Hz ES was applied to the ears for 20 min/day (10 min for each ear) for 7 days continuously. The step-through time of the passive avoidance test was greater in the ES group than in the control group (300.0 ± 0.0 s vs 45.0 ± 26.7 s, p < 0.05). Our results showed that neither neurological deficit score nor motor functions were improved after 2-Hz ES (4.0 ± 0 vs 4.5 ± 0.8, p > 0.05). The numbers of nicotinic acetylcholine receptor α4 positively stained cells in the CA2 and dentate gyrus of the hippocampus were 19.0 ± 11.5 and 269.2 ± 79.3, respectively, in the ES group, which were greater than those in the control group (7.0 ± 5.9 and 165.5 ± 30.8, respectively) (both p < 0.05). These results suggested that 2-Hz ES of the ears ameliorated learning and memory impairment in rats with ischemia-reperfusion injury. ES of the ears has neuroprotective effects, which are related to acetylcholine release.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Nuclear / metabolism
  • Disease Models, Animal
  • Ear / physiology*
  • Electric Stimulation*
  • Glial Fibrillary Acidic Protein / metabolism
  • Hippocampus / metabolism
  • Ki-67 Antigen / metabolism
  • Male
  • Maze Learning / physiology*
  • Memory / physiology*
  • Microscopy, Fluorescence
  • Nerve Tissue Proteins / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Nicotinic / metabolism
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / pathology*

Substances

  • Antigens, Nuclear
  • Glial Fibrillary Acidic Protein
  • Ki-67 Antigen
  • Nerve Tissue Proteins
  • Rbfox3 protein, rat
  • Receptors, Nicotinic
  • nicotinic acetylcholine receptor alpha4 subunit