This study is looking at learning and memory improvement with auricular stimulation (estim) in animals.  As the first sentence says, “Ear acupuncture enhances the secretion of acetylcholine, which has anti-inflammatory effects.”  I’ve been using ear stim in the clinic as many patients know.  It is purported to enhance vagal activity which leads to acetylcholine release. Improved vagal activity leads to many positive effects, anti-inflammatory among them.

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

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

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.