AUTHOR=Nguyen Thanh Tin , Nam Gi-Sung , Kang Jin-Ju , Han Gyu Cheol , Kim Ji-Soo , Dieterich Marianne , Oh Sun-Young 

TITLE=Galvanic Vestibular Stimulation Improves Spatial Cognition After Unilateral Labyrinthectomy in Mice

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.716795

DOI=10.3389/fneur.2021.716795

ISSN=1664-2295

ABSTRACT=<p><bold>Objectives:</bold> To investigate the deficits of spatial memory and navigation from unilateral vestibular deafferentation (UVD) and to determine the efficacy of galvanic vestibular stimulation (GVS) for recovery from these deficits using a mouse model of unilateral labyrinthectomy (UL).</p><p><bold>Methods:</bold> Thirty-six male C57BL/6 mice were allocated into three groups that comprise a control group and two experimental groups, UVD with (GVS group) and without GVS intervention (non-GVS group). In the experimental groups, we assessed the locomotor and cognitive behavioral function before (baseline) and 3, 7, and 14 days after surgical UL, using the open field (OF), Y maze, and Morris water maze (MWM) tests. In the GVS group, the stimulations were applied for 30 min daily from postoperative day (POD) 0–4 <italic>via</italic> the electrodes inserted subcutaneously close to both bony labyrinths.</p><p><bold>Results:</bold> Locomotion and spatial cognition were significantly impaired in the mice with UVD non-GVS group compared to the control group. GVS significantly accelerated recovery of locomotion compared to the control and non-GVS groups on PODs 3 (<italic>p</italic> &lt; 0.001) and 7 (<italic>p</italic> &lt; 0.05, Kruskal–Wallis and Mann–Whitney <italic>U</italic> tests) in the OF and Y maze tests. The mice in the GVS group were better in spatial working memory assessed with spontaneous alternation performance and spatial reference memory assessed with place recognition during the Y maze test than those in the non-GVS group on POD 3 (<italic>p</italic> &lt; 0.001). In addition, the recovery of long-term spatial navigation deficits during the MWM, as indicated by the escape latency and the probe trial, was significantly better in the GVS group than in the non-GVS group 2 weeks after UVD (<italic>p</italic> &lt; 0.01).</p><p><bold>Conclusions:</bold> UVD impairs spatial memory, navigation, and motor coordination. GVS accelerated recoveries in short- and long-term spatial memory and navigation, as well as locomotor function in mice with UVD, and may be applied to the patients with acute unilateral vestibular failure.</p>