Abstract
Low-frequency repetitive transcranial magnetic stimulation (1-Hz rTMS) is a promising noninvasive tool for the treatment of depression. Hippocampal neuronal plasticity is thought to play a pivotal role in the pathophysiology of depressive disorders and the mechanism of action of antidepressant treatments. We investigated the effect of 1-Hz rTMS treatment on hippocampal dentate gyrus structural plasticity and related emotional behaviors modifications. Experimentally, adult male mice received either five days of 1-Hz rTMS or Sham stimulation. After stimulation, the mice underwent a battery of tests for anxiety-like and depression-like behaviors. We also tested the effect of treatment on mature and newly generated granule cell dendritic complexity. Our data showed that 1-Hz rTMS induced structural plasticity in mature granule cells, as evidenced by increased dendritic length and number of intersections. However, the stimulation did not increase the proliferation of the dentate gyrus progenitor cells. On the contrary, the stimulated mice showed increased dendritic complexity of newly generated neurons. Moreover, 1-Hz rTMS resulted in antidepressant-like effects in the tail suspension test, but it did not affect anxiety-like behaviors. Therefore, our results indicate that 1-Hz rTMS modulates dentate gyrus morphological plasticity in mature and newly generated neurons. Furthermore, our data provide some evidence of an association between the antidepressant-like activity of 1-Hz rTMS and structural plasticity in the hippocampus.
Highlights
Major depressive disorders (MDD) are highly prevalent medical conditions [1] that have a significantly negative impact on quality of life [2]
Our results indicate a modulatory effect of 1-Hz Repetitive transcranial magnetic stimulation (rTMS) on dendritic morphology in mature and newly generated granule cells
One-Hz rTMS-treated mice exhibited less immobility when challenged in an inescapable such as the TST, while the anxiety-like behavior tests (OF, Novelty-suppressed feeding (NSF), and Elevated plus maze (EPM)) were not modulated situation such as the TST, while the anxiety-like behavior tests (OF, NSF, and EPM) were not by the stimulation protocol. These results indicate that 1-Hz rTMS treatment does not increase modulated by the stimulation protocol
Summary
Major depressive disorders (MDD) are highly prevalent medical conditions [1] that have a significantly negative impact on quality of life [2]. Since the available pharmacotherapies are effective in 50–60% of MDD patients and may have significant side effects [3,4,5], there has been a growing interest in the development of nonpharmacological methods to treat depression. Repetitive transcranial magnetic stimulation (rTMS) is a brain stimulation intervention that noninvasively modulates brain circuitries. High-frequency (HF) rTMS (5–25 Hz) has antidepressant efficacy and it has become an established treatment option for drug-resistant depression [6]. Res. Public Health 2020, 17, 4074; doi:10.3390/ijerph17114074 www.mdpi.com/journal/ijerph
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
