Low frequency repetitive transcranial magnetic stimulation promotes plasticity of the visual cortex in adult amblyopic rats

Jing Zheng; Wenqiu Zhang; Longqian Liu; Maurice Keng Hung Yap

doi:10.3389/fnins.2023.1109735

Low frequency repetitive transcranial magnetic stimulation promotes plasticity of the visual cortex in adult amblyopic rats

Front Neurosci. 2023 Jan 19:17:1109735. doi: 10.3389/fnins.2023.1109735. eCollection 2023.

Authors

Jing Zheng^{1

2}, Wenqiu Zhang^{1

2}, Longqian Liu^{1

2}, Maurice Keng Hung Yap³

Affiliations

¹ Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China.
² Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu, China.
³ School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.

Abstract

The decline of visual plasticity restricts the recovery of visual functions in adult amblyopia. Repetitive transcranial magnetic stimulation (rTMS) has been shown to be effective in treating adult amblyopia. However, the underlying mechanisms of rTMS on visual cortex plasticity remain unclear. In this study, we found that low-frequency rTMS reinstated the amplitude of visual evoked potentials, but did not influence the impaired depth perception of amblyopic rats. Furthermore, the expression of synaptic plasticity genes and the number of dendritic spines were significantly higher in amblyopic rats which received rTMS when compared with amblyopic rats which received sham stimulation, with reduced level of inhibition and perineuronal nets in visual cortex, as observed via molecular and histological investigations. The results provide further evidence that rTMS enhances functional recovery and visual plasticity in an adult amblyopic animal model.

Keywords: GABA; amblyopia; perineuronal nets; repetitive transcranial magnetic stimulation; visual plasticity.

Grants and funding

This work was supported by the National Natural Science Foundation of China (Grant Number 81800863). This work was also partially supported by Sichuan Science and Technology Program (Grant Number 2019YFS0247).