Chronic Repetitive Transcranial Magnetic Stimulation Research Articles

Chronic repetitive transcranial magnetic stimulation (rTMS) on sleeping quality and mood status in drug dependent male inpatients during abstinence

BackgroundDrug abstinence is accompanied by aversive experiences and lasting changes in mood status and worsening sleep quality. This study investigated the potential effects of chronic repetitive transcranial magnetic stimulation (rTMS) in substance dependent inpatients during abstinence. MethodsThis was a double-blinded study with 105 males inpatients dependent on heroin or methamphetamine (average abstinence time was six months). The inpatients were randomly divided into 10 Hz intervention (n = 40), sham stimulation (n = 40) and control (waiting list, no treatment) (n = 25) groups. Five sessions of rTMS stimulation were administrated for six consecutive weeks, reaching a total of 180,000 pulses. There was no intervention for control group. Patients were assessed using the Pittsburgh Sleep Quality Index (PSQI), Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) were assessed prior to and after six weeks of intervention. ResultsThe results showed that six weeks of rTMS treatment significantly improved the sleep quality (p < 0.001), alleviated depression (p < 0.001) and anxiety state (p < 0.001) of substance dependent inpatients in early abstinence. Furthermore, the active TMS group showed significant differences between sham and control groups. ConclusionThese findings suggested that chronic rTMS treatment have positive effects for substance dependent inpatients during abstinence. Future studies are required to understand the underlying mechanism for improving different clinical symptoms.

Chronic repetitive transcranial magnetic stimulation enhances GABAergic and cholinergic metabolism in chronic unpredictable mild stress rat model: 1H-NMR spectroscopy study at 11.7 T

Gamma-animobutyric acid (GABA) systems are emerging as targets for development of medications for mood disorders. Deficits in GABA-containing neurons are consistently reported in psychiatric disease, particularly in the prefrontal cortex and hippocampus. Repetitive transcranial magnetic stimulation (rTMS) that use magnetic field to stimulate focal cortical regions with electrical current have a potential therapeutic effects with non-invasive and painless method. In this study, we used chronic unpredictable mild stress (CUMS) rat model of depression to investigate the behavioral and neurochemical alterations. Furthermore, chronic rTMS treatment effect on neurochemical profile in prefrontal cortex and hippocampus of rats were assessed. The CUMS induced significant reductions in absolute sucrose intake and sucrose preference. In addition, high-resolution 1H-NMR spectra from brain extracts revealed significantly reduced prefrontal and hippocampal GABA levels in CUMS rats compared to control. The behavioral and neurochemical changes were reversed by chronic rTMS treatment. Furthermore, chronic rTMS treatments results in differential effects on different brain regions. Our results suggest specific and regionally different metabolic response to chronic rTMS treatment in animal model of depression.

Chronic repetitive transcranial magnetic stimulation failed to change dopamine synthesis rate: Preliminary L‐[β‐11C]DOPA positron emission tomography study in patients with depression

We have examined the effects of repetitive transcranial magnetic stimulation (rTMS) on central dopaminergic function in patients with depression using positron emission tomography with L-[β-11C]DOPA, a ligand to assess the rate of endogenous dopamine synthesis. Eight patients were treated with 10-daily sessions of rTMS over the left dorsolateral prefrontal cortex. Positron emission tomography scanning was performed in each patient twice, before the first session and 1 day after the last session. Although four out of eight patients responded to rTMS, there were no changes in the striatal dopamine synthesis rate (k) following rTMS. These results suggest that chronic rTMS had a limited effect on the dopaminergic system.

The effects of chronic repetitive transcranial magnetic stimulation on glutamate and gamma-aminobutyric acid in rat brain

Recent studies have shown that repetitive transcranial magnetic stimulation (rTMS) has therapeutic potential for some neurological and psychiatric disorders. However, the neurobiological effects of this tool are not sufficiently explained so far, previous research reported that rTMS can change dopamine release, there have been few studies to examine a possible effect of rTMS on amino acid neurotransmitter. This study aimed to determine the effects of chronic rTMS on glutamate and gamma-aminobutyric acid concentration in the rat brain. Sprague–Dawley rat was subject to 500 pulses of 0.5 Hz rTMS for 15 days, or sham stimulation. After last stimulation, glutamate and gamma-aminobutyric acid content were measured by high performance liquid chromatography (HPLC). Results showed that the content of glutamate and gamma-aminobutyric acid increased significantly in hippocampus and striatum after chronic rTMS, but reduced significantly in the hypothalamus. These results indicate that chronic rTMS has a modulatory effect on the glutamate and gamma-aminobutyric acid systems. This change in amino acid neurotransmitter may contribute to its beneficial effects.

Sex differences in antidepressant-like effect of chronic repetitive transcranial magnetic stimulation in rats

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neurophysiological technique. Pre-clinical and clinical studies supported that rTMS might have antidepressant effects. However, whether antidepressant effect of chronic rTMS is gender-dependent is still unknown. In this study, male and female Wistar rats received 10-day rTMS (4 trains of 15 Hz; 200 stimuli/day; 1.0 T) or control condition, and then were subjected to the forced-swim test (FST). We found that female rats consistently showed higher activity levels than males in FST and revealed the significant effects of gender and rTMS as well as the interaction of gender and rTMS. The result suggested the antidepressant-like effects of chronic rTMS on behavioral components in FST are gender-dependent. The gender discrepancy related to rTMS should not be neglected in antidepressant treatment of rTMS.

Chronic repetitive transcranial magnetic stimulation is antidepressant but not anxiolytic in rat models of anxiety and depression

Transcranial magnetic stimulation (TMS) has been proposed as a treatment for depression and anxiety disorders. While the antidepressant effect has been modelled in animals, there have been few attempts to examine a possible anxiolytic effect of repetitive TMS (rTMS) in animal models. We administered 18 days of rTMS to male Sprague-Dawley rats. On days 10 through 18, rats were tested in several anxiety models (social interaction, emergence, elevated plus-maze, and predator odor avoidance) and in the forced swim test. No group differences were apparent on any of the anxiety models, while TMS produced an antidepressant effect in the forced swim test. Interestingly, on day 1 of the forced swim test, the home cage control group displayed increased swimming behaviour compared with sham-treated animals, suggesting an observable level of stress may have accompanied sham treatment. The results from the forced swim test suggested that TMS had modest antidepressant properties, but it did not show anxiolytic properties in the models examined. The study also suggested that stress associated with handling should be taken into account in the interpretation of TMS studies in animals.

Chronic rTMS induces subsensitivity of post-synaptic 5-HT1A receptors in rat hypothalamus.

Chronic administration of several antidepressants, notably the selective serotonin re-uptake inhibitors (SSRIs) induces sub-sensitivity of post-synaptic 5-HT1A receptors in the hypothalamus. Chronic repetitive transcranial magnetic stimulation (rTMS) is a form of treatment for depression which is often compared to electroconvulsive shock therapy (ECT). rTMS was applied to rats either on a single occasion (acute) or daily for 8 d (chronic). Twenty-four hours after the last treatment, the rats were injected with saline or 8-OH-DPAT (50 microg/kg). The rats were killed 20 min later and trunk blood taken for measurement of corticosterone and ACTH levels. Chronic rTMS did not affect basal corticosterone or ACTH levels but significantly blunted the responses to 8-OH-DPAT, while acute rTMS had no effect on either basal or 8-OH-DPAT-stimulated responses. In common with several other antidepressant treatments, chronic rTMS reduces the sensitivity of post-synaptic 5-HT1A receptors in the hypothalamus. This effect may be significant in relation to the therapeutic mechanism of rTMS.

Chronic repetitive transcranial magnetic stimulation (rTMS) does not affect tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) expression in rats in vivo.

SynapseVolume 46, Issue 1 p. 45-47 Chronic repetitive transcranial magnetic stimulation (rTMS) does not affect tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH) expression in rats in vivo Armand Hausmann, Corresponding Author Armand Hausmann [email protected] Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaInnsbruck University Hospital, Department of General Psychiatry, Anichstrasse 35, A – 6020 Innsbruck, AustriaSearch for more papers by this authorChristine Schermer, Christine Schermer Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this authorHartmann Hinterhuber, Hartmann Hinterhuber Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this authorChristian Humpel, Christian Humpel Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this author Armand Hausmann, Corresponding Author Armand Hausmann [email protected] Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaInnsbruck University Hospital, Department of General Psychiatry, Anichstrasse 35, A – 6020 Innsbruck, AustriaSearch for more papers by this authorChristine Schermer, Christine Schermer Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this authorHartmann Hinterhuber, Hartmann Hinterhuber Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this authorChristian Humpel, Christian Humpel Innsbruck University Hospital, Laboratory of Psychiatry, Department of General Psychiatry, Innsbruck, AustriaSearch for more papers by this author First published: 17 July 2002 https://doi.org/10.1002/syn.10110Citations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume46, Issue1October 2002Pages 45-47 RelatedInformation

Effect of Chronic Repetitive Transcranial Magnetic Stimulation on Regional Cerebral Blood Flow and Regional Cerebral Glucose Uptake in Drug Treatment-Resistant Depressives

Brain imaging studies have shown that repetitive transcranial magnetic stimulation (rTMS) is biologically active. The aim of the present study was to investigate the patterns of the regional cerebral glucose uptake rate (rCMRGlu) and regional ^99mTc HMPAO uptake rate (regional cerebral blood flow; rCBF) during a series of therapeutic rTMS sessions at low frequency. Four drug-resistant depressed patients underwent 10 rTMS sessions as an add-on measure over 14 days. One day before and 1 day after the TMS series, 511-keV SPECT with simultaneous ¹⁸F-fluorodeoxyglucose and ^99mTc HMPAO measurements were carried out. All patients showed a good clinical outcome. Statistically significant common changes in rCBF and rCMRGlu patterns were found in the upper frontal regions bilaterally in terms of increased uptake rates and in the left orbitofrontal cortex in terms of decreased uptake rates of both isotopes compared to controls. However, the lateralization patterns of rCBF and rCMRGlu after rTMS treatment revealed marked differences. Thus, although no relevant changes in lateralization of the glucose uptake were observed, a clear right-sided preponderance of rCBF also in areas remote from the stimulation site was described. Therapeutic rTMS seems to influence distinct cortical regions, affecting rCBF and rCMRGlu in a homogeneous manner as well as in different ways, which are probably region dependent and illness related. The role of the stimulation coil placement site should be taken into account.

Chronic repetitive transcranial magnetic stimulation induces subsensitivity of presynaptic serotonergic autoreceptor activity in rat brain

Repetitive transcranial magnetic stimulation (rTMS) is a novel procedure which has proven effective in the treatment of major depression. We administered rTMS chronically to rats in order to determine whether this procedure affected serotonergic neurotransmission in the prefrontal cortex. Basal 5-HT levels, and the effects of challenges with the 5-HT1A receptor agonist 8-OH-DPAT and the 5-HT1B antagonist GR 127935 on 5-HT levels were determined using in vivo microdialysis. Rats which had undergone chronic rTMS showed reduced responses to both challenges, indicating subsensitivity of both the presynaptic 5-HT1A autoreceptors situated somatodendritically in the raphe nuclei and the 5-HT1B autoreceptors situated on nerve terminals. Since such subsensitivity has been demonstrated after other antidepressant treatments, our results indicate that these treatments and rTMS may have a common mechanism of action.

Chronic repetitive transcranial magnetic stimulation alters β-adrenergic and 5-HT 2 receptor characteristics in rat brain

Repetitive transcranial magnetic stimulation (rTMS) has been shown to affect mood in health and disease. Evidence to date has demonstrated an antidepressant potential for low- and high-frequency rTMS treatment. In animal behavioral models of depression magnetic stimulation of the brain induced similar effects to those of electroconvulsive shock (ECS). In this study the effects of repeated rTMS on rat brain noradrenaline, dopamine, serotonin and their metabolites levels, as well as on β-adrenergic and 5-HT 2 receptor characteristics were studied. After 10 days of treatment, β-adrenergic receptors were significantly up regulated in the frontal cortex, down regulated in the striatum and were unchanged in the hippocampus. 5-HT 2 receptors were down regulated in the frontal cortex and were not changed in the other brain areas. No change in benzodiazepine receptors in the frontal cortex and cerebellum were demonstrated. These findings demonstrate specific and selective alterations induced by repeated rTMS, which are distinct from those induced by other antidepressant treatments. TMS therapeutic effects in humans and behavioral and biochemical effects in animal, suggest that TMS has a unique mechanism of action which requires further investigation.

Repetitive transcranial magnetic stimulations of the rat. Effect of acute and chronic stimulations on pentylenetetrazole-induced clonic seizures.

Repetitive transcranial magnetic stimulation (RTMS) has been reported to induce epileptic seizures in normal control and in epileptic patients. Therefore we characterized the effect of acute or chronic stimulations with RTMS on the induction of pentylenetetrazole (PTZ)-induced clonic seizures in the rat. Male Wistar rats were stimulated with a 13-cm coil with a stimulus frequency of 50 Hz. The motor threshold (Tm) was determined by a single transcranial stimulus. Acute stimulation was performed with a stimulus intensity of 0.9 x Tm and 1.5 x Tm using a duration of the train of stimuli of five seconds. Chronic stimulation was performed with a duration of the train of stimuli of one and five seconds using a stimulus intensity of 1.8 x Tm, every day for 30 days. Time to onset of PTZ-induced clonic seizure was determined after the acute stimulation or the last stimulation in chronic RTMS. In the groups of rats receiving acute RTMS (0.9 and 1.5 x Tm) no seizures developed. No differences were observed in time to onset of clonic seizures after PTZ injection compared to control rats. In the group of rats receiving chronic RTMS some rats showed facial contractions, chewing or head movements during or immediately after the stimulations. None of the rats developed tonic or clonic seizures in relation to RTMS. Time to onset of PTZ clonic seizures was reduced in both groups receiving RTMS with a stimulus duration of one (P < 0.01) and five (P < 0.05) seconds compared to control rats. The results from this study suggest that acute suprathreshold stimulation with a stimulus frequency of 50 Hz does not affect the induction of clonic PTZ seizures, whereas chronic (daily) stimulations have a facilitatory effect. This indicates that chronic stimulation with RTMS may induce a kindling process in the rat. Chronic RTMS stimulation may therefore represent an interesting alternative non-invasively kindling model to chemical and electrical stimulations.