Alterations in levels of neurotransmitters γ-aminobutyric acid (GABA) and glutamate may underlie the mechanism by which repetitive transcranial magnetic stimulation (rTMS) has efficacy as a treatment for major depressive disorder (MDD). This study used proton magnetic resonance spectroscopy (HMRS) to investigate the effect of rTMS on levels of GABA and combined glutamate/glutamine measure (Glx). Treatment-resistant, currently depressed individuals participated in a naturalistic open-label study with rTMS treatment administered at 10 Hz and 120% of resting motor threshold to the left dorsolateral prefrontal cortex (DLPFC) for 20 sessions. H MRS measures were collected at baseline and after four weeks of daily treatment. GABA and Glx were measured from both the left DLPFC and a control region (right motor cortex). Twenty-seven participants completed the study and were included in the analysis. Contrary to previous studies, no difference in GABA was observed following treatment. Glx levels were found to significantly increase in both the left DLPFC and right motor cortex voxels but this increase did not correlate with antidepressant response. Glx levels were found to increase following rTMS, not only underlying the site of stimulation but also at a distant control voxel suggesting a degree of non-specificity in response to therapy.
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http://dx.doi.org/10.1016/j.pscychresns.2021.111377 | DOI Listing |
Alzheimers Dement
December 2024
Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Background: Alzheimer's disease (AD) is characterized by the accumulation of amyloid-β (Aβ) plaques and tau tangles in the brain, and neurotransmission dysfunctions. Indeed, our group recently demonstrated that the γ-aminobutyric acid (GABA)ergic system is vulnerable to AD pathology in humans. However, whether this vulnerability is also present in AD rodent models is still unknown.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
December 2024
Department of Psychiatry, Medical University of Gdańsk, Smoluchowskiego 17 st., 81-214 Gdańsk, Poland.
Dev Cell
December 2024
State Key Laboratory of Common Mechanism Research for Major Diseases, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China. Electronic address:
The neurotransmitter gamma-aminobutyric acid (GABA) has been thought to be involved in the development of some types of cancer. Yet, the de novo synthesis of GABA and how it functions in hepatocellular carcinoma (HCC) remain unclear. Here, we report that SLC6A12 acts as a transporter of GABA, and that aldehyde dehydrogenase 9 family member A1 (ALDH9A1), not glutamate decarboxylase 1 (GAD1), generates GABA in human HCC.
View Article and Find Full Text PDFNat Commun
December 2024
Department of Ophthalmology, Columbia University, New York, NY, USA.
Best1 and Best2 are two members of the bestrophin family of anion channels critically involved in the prevention of retinal degeneration and maintenance of intraocular pressure, respectively. Here, we solved glutamate- and γ-aminobutyric acid (GABA)-bound Best2 structures, which delineate an intracellular glutamate binding site and an extracellular GABA binding site on Best2, respectively, identified extracellular GABA as a permeable activator of Best2, and elucidated the co-regulation of Best2 by glutamate, GABA and glutamine synthetase in vivo. We further identified multiple small molecules as activators of the bestrophin channels.
View Article and Find Full Text PDFArch Razi Inst
June 2024
Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Gastrointestinal dysfunction is a severe and common complication in diabetic patients. Some evidence shows that gamma-aminobutyric acid (GABA) and glutamate contribute to diabetic gastrointestinal abnormalities. Therefore, we examined the impact of prolonged treatment with insulin and magnesium supplements on the expression pattern of GABA type A (GABA-A), GABA-B, and N-methyl-D-aspartate (NMDA) glutamate receptors as well as nitric oxide synthase 1 (NOS-1) in the stomach of type 2 diabetic rats.
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