The Effects of 1-Hz rTMS on Emotional Behavior and Dendritic Complexity of Mature and Newly Generated Dentate Gyrus Neurons in Male Mice

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.

Manipulating the Level of Sensorimotor Stimulation during LI-rTMS Can Improve Visual Circuit Reorganisation in Adult Ephrin-A2A5-/- Mice

“…It would be interesting in future studies to consider the application of low frequency stimulation paradigms in models where it is desirable to decrease cortical excitability. For example, 1 Hz stimulation has been shown to decrease cortical excitability in human and animal models [ 81 , 82 ], and alter dendritic morphology in mouse hippocampal slices [ 83 ]. Combining different tasks and stimulation paradigms may allow the selective enhancement of specific plasticity processes, leading to optimal repair.…”

Post-Discharge Depression Status for Survivors of Extracorporeal Membrane Oxygenation (ECMO): Comparison of Veno-Venous ECMO and Veno-Arterial ECMO

“…Depression was associated with a decrease in dendritic spine density and dendritic complexities. Furthermore, NIBS techniques are now used to treat depression, modulate spine density, and dendritic complexities [ 55 , 56 ]. Existential phenomenological psychotherapy (EPP) was demonstrated to augment pharmacological support for patients with mood disorders for nearly a century, which helps patients find meaning and purpose in life to override physical limitations [ 52 ].…”

Vitamin D and Depressive Symptoms in Adults with Multiple Sclerosis: A Scoping Review

“…Lastly, vitamin D is a strong regulator of brain morphology and neurogenesis [ 67 , 68 ]. Previous studies indicate that animal models of both depression and MS show abnormal hippocampal neurogenesis and neuronal morphology [ 69 ] and that morphological brain plasticity (neurogenesis, dendritic spine density, and dendritic complexity) is modulated by antidepressant treatments [ 70 , 71 ]. On the whole, preclinical results point to a brain plasticity modulating activity of vitamin D and support its role in the pathogenesis of depression in pwMS.…”