“The anti-depressant effect of repetitive transcranial magnetic stimulation (rTMS), a clinically-useful treatment for depression, is associated with changes to the endocannabinoid system (ECS).
However, it is currently unknown whether different frequencies of rTMS alter the ECS differently. To test this, rats exposed to chronic unpredictable stress (CUS) were treated with rTMS at two different frequencies (5 (high) or 1 Hz (low), 1.26 Tesla) for 7 consecutive days.
Interestingly, we found that only high-frequency rTMS ameliorated depressive-like behaviors and normalized the expression of hippocampal synaptic proteins in CUS-treated rats;
Collectively, our results suggest that high-frequency rTMS exerts its anti-depressant effect by up-regulating diacylglycerol lipase alpha (DAGLα) and cannabinoid type 1 receptor (CB1R).”
https://www.ncbi.nlm.nih.gov/pubmed/31229467
https://www.sciencedirect.com/science/article/pii/S0091305719301376?via%3Dihub
“Transcranial magnetic stimulation (TMS), also known as repetitive transcranial magnetic stimulation (rTMS), is a noninvasive form of brain stimulation in which a changing magnetic field is used to cause electric current at a specific area of the brain through electromagnetic induction. An electric pulse generator, or stimulator, is connected to a magnetic coil, which in turn is connected to the scalp. The stimulator generates a changing electric current within the coil which induces a magnetic field; this field then causes a second inductance of inverted electric charge within the brain itself. Adverse effects of TMS are rare, and include fainting and seizure. Other potential issues include discomfort, pain, hypomania, cognitive change, hearing loss, and inadvertent current induction in implanted devices such as pacemakers or defibrillators” https://www.sciencedirect.com/science/article/pii/S0091305719301376?via%3Dihub
“Neuropathic pain (NP) is associated with chronic hyperglycemia and emotional disorders such as depression in diabetic patients, complicating the course of treatment. Drugs currently used to treat NP have undesirable side effects, so research on other natural sources has been required.
“Altered endocannabinoid (eCB) signaling is suggested as an important contributor to the pathophysiology of depression.
“Major depressive disorder is a devastating psychiatric disease that afflicts up to 17% of the world’s population. Postmortem brain analyses and imaging studies of patients with depression have implicated basal lateral amygdala (BLA) dysfunction in the pathophysiology of depression. However, the circuit and molecular mechanisms through which BLA neurons modulate depressive behavior are largely uncharacterized. Here, in mice, we identified that BLA cholecystokinin (CCK) glutamatergic neurons mediated negative reinforcement via D2 medium spiny neurons (MSNs) in the nucleus accumbens (NAc) and that chronic social defeat selectively potentiated excitatory transmission of the CCKBLA-D2NAc circuit in susceptible mice via reduction of presynaptic cannabinoid type-1 receptor (CB1R). Knockdown of CB1R in the CCKBLA-D2NAc circuit elevated synaptic activity and promoted stress susceptibility. Notably, selective inhibition of the CCKBLA-D2NAc circuit or administration of synthetic cannabinoids in the NAc was sufficient to produce antidepressant-like effects. Overall, our studies reveal the circuit and molecular mechanisms of depression.”