Emerging evidence demonstrates the potential involvement of hippocampal GABAergic transmission in the process of memory acquisition and consolidation, while no consistent report is available to address the adaptation of hippocampal GABAergic transmission and its contribution to memory deficiency in the setting of Alzheimer's disease (AD). Brain-derived neurotrophic factor (BDNF) is a key molecule that regulates GABAergic transmission. In the brain, mature BDNF is generated from the proteolytic cleavage of proBDNF, while BDNF and proBDNF have differential effects on central GABAergic transmission. First, the present study reports a remarkable increase of proBDNF/BNDF ratio in the hippocampal CA1 area in rodent models of AD, indicating a potential impaired process of BDNF maturation from proBDNF cleavage. We report a suppressed hippocampal GABAergic strength, potentially resulting from the reduced expression of anion chloride co-transporter KCC2 and subsequent positive shift of GABAergic Cl-equilibrium potential (E-), which is attenuated by microinjection of BDNF with proBDNF inhibitor TAT-Pep5. We also show that normalization of proBDNF/BDNF signaling or GABAergic E-by intracerebroventricular (i.c.v.) administration of bumetanide remarkably improves the cognitive performance in Morris water maze test and fear conditioning test in rodent models of AD. These results demonstrate a critical role of hippocampal proBDNF/BDNF in regulating GABAergic transmission and contributing to memory dysfunction in rodent models of AD.
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http://dx.doi.org/10.1016/j.ejphar.2022.174771 | DOI Listing |
Pharmacol Res
January 2025
Center for Brain Research, Department of Molecular Neurosciences, Medical University Vienna, Vienna, Austria. Electronic address:
α6-containing GABA receptors (α6GABARs) are strongly expressed in cerebellar granule cells and are of central importance for cerebellar functions. The cerebellum not only is involved in regulation of motor activity, but also in regulation of thought, cognition, emotion, language, and social behavior. Activation of α6GABARs enhances the precision of sensory inputs, enables rapid and coordinated movement and adequate responses to the environment, and protects the brain from information overflow.
View Article and Find Full Text PDFFront Cell Neurosci
January 2025
The Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Asahikawa, Japan.
The evolution of brain-expressed genes is notably slower than that of genes expressed in other tissues, a phenomenon likely due to high-level functional constraints. One such constraint might be the integration of information by neuron assemblies, enhancing environmental adaptability. This study explores the physiological mechanisms of information integration in neurons through three types of synchronization: chemical, electromagnetic, and quantum.
View Article and Find Full Text PDFNeuropharmacology
January 2025
Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton, NY, 13902-6000, USA. Electronic address:
Alcohol binge drinking has a multitude of effects on CNS function, including changes in inflammatory cytokines such as IL-6 and IL-1β that may contribute to mood fluctuations associated with the intoxication-withdrawal cycle. Widely throughout the brain, including the amygdala, IL-6 mRNA is enhanced during intoxication, whereas IL-1β is initially suppressed during alcohol intoxication, with increased expression seen shortly after ethanol clearance, during acute hangover. Furthermore, induction of neuroimmune genes appears to be muted during adolescence in the amygdala, suggesting a broader functional immaturity of the adolescent neuroimmune system in structures involved in negative affect associated with ethanol exposure.
View Article and Find Full Text PDFPharmacol Res
January 2025
Post-surgical pain affects millions each year, hindering recovery and quality of life. Surgical procedures cause tissue damage and inflammation, leading to peripheral and central sensitization, resulting in pain at rest or hyperalgesia to mechanical stimuli, among others. In a rat model for post-surgical pain, spinal GABAergic transmission via GABA receptors reduces mechanical hypersensitivity but has no effect on pain at rest.
View Article and Find Full Text PDFEur J Neurosci
January 2025
Department of Pharmacology, University of Oxford, Oxford, UK.
Cannabinoid receptor 1 (CB1) regulates synaptic transmission through presynaptic receptors in nerve terminals, and its physiological roles are of clinical relevance. The cellular sources and synaptic targets of CB1-expressing terminals in the human cerebral cortex are undefined. We demonstrate a variable laminar pattern of CB1-immunoreactive axons and electron microscopically show that CB1-positive GABAergic terminals make type-2 synapses innervating dendritic shafts (69%), dendritic spines (20%) and somata (11%) in neocortical layers 2-3.
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