High frequency transcranial magnetic stimulation mimics the effects of ECS in upregulating astroglial gene expression in the murine CNS
ABSTRACT The present study evaluates the consequences of high frequency (25 hz) trans-cranial magnetic stimulation on the expression of glial fibrillary acidic protein (GFAP) in the murine CNS. Trains of transcranial magnetic stimulation (1-30 trains at 25 Hz, 10 s duration) were delivered to mice via 5-cm diameter round coils. The stimulation produced stimulus-locked motor responses but did not elicit behavioral seizures. GFAP mRNA levels were evaluated 12, 24, 36, 48 h, 4 days, and 8 days following stimulation by in situ hybridization. Following multiple 25 Hz trains, there were dramatic increases in the levels of GFAP mRNA in the hippocampal dentate gyrus; more modest increases were observed in the cerebral cortex. The selective increases in GFAP mRNA in the dentate gyrus were similar to those observed following single electroconvulsive seizures (ECS). These results indicate that trans-cranial magnetic stimulation can be used to modulate astroglial gene expression, inducing the first stage of a reactive response that is similar to what occurs following nervous system injury.
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ABSTRACT: Transcranial magnetic stimulation is a non-invasive tool in clinical diagnostics and therapy for physiological and psychological diseases and has an increased application in experimental neurophysiology. Despite this, the mechanisms of magnetic stimulation of the central nervous system remain still unclear. We applied sinus-shaped high frequency magnetic fields in different stimulation patterns and repeated treatments to cell cultures derived from frontal cortex of murine embryos (BALB/cOlaHsd mice) to elucidate the effects of repetitive magnetic stimulation on the gene expression of in vitro cultured neural cells. Gene expression profiling was performed by using qRT-PCR array and single qRT-PCR analyses. Our methodological approach using microelectrode arrays data recording and analysis minimizes variations in transcriptome analysis arising from cell differentiation status and tissue complexity. With 10 significant changes in gene expression out of 171 genes using Alzheimer disease and neurodegeneration related qRT-PCR arrays we demonstrate significant impact of repetitive magnetic stimulation on the mRNA transcript of neural cell cultures. Sixteen candidate genes were analyzed using single qRT-PCR in a replicated statistical design, which provided more precise estimates of differences in expression profiles. We discussed the utility of the experimental methods used for cell culture selection and the changes in gene expression considering physiological aspects.Neuroscience Letters 08/2012; 526(2):122-7. DOI:10.1016/j.neulet.2012.08.024 · 2.06 Impact Factor
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ABSTRACT: Post-mortem histopathological studies report on reduced glial cell numbers in various frontolimbic areas of depressed patients implying that glial loss together with abnormal functioning could contribute to the pathophysiology of mood disorders. Astrocytes are regarded as the most abundant cell type in the brain and known for their housekeeping functions, but as recent developments suggest, they are also dynamic regulators of synaptogenesis, synaptic strength and stability and they control adult hippocampal neurogenesis. The primary aim of this review was to summarize the abundant experimental evidences demonstrating that antidepressant therapies have profound effect on astrocytes. Antidepressants modify astroglial physiology, morphology and by affecting gliogenesis they probably even regulate glial cell numbers. Antidepressants affect intracellular signaling pathways and gene expression of astrocytes, as well as the expression of receptors and the release of various trophic factors. We also assess the potential functional consequences of these changes on glutamate and glucose homeostasis and on synaptic communication between the neurons. We propose here a hypothesis that antidepressant treatment not only affects neurons, but also activates astrocytes, triggering them to carry out specific functions that result in the reactivation of cortical plasticity and can lead to the readjustment of abnormal neuronal networks. We argue here that these astrocyte specific changes are likely to contribute to the therapeutic effectiveness of the currently available antidepressant treatments and the better understanding of these cellular and molecular processes could help us to identify novel targets for the development of antidepressant drugs.European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 05/2012; 23(3). DOI:10.1016/j.euroneuro.2012.04.017 · 5.40 Impact Factor