Although acidosis may be involved in neuronal death, the participation of Na(+)/H(+) exchanger (NHE) in delayed neuronal death in the hippocampal CA1 region induced by transient forebrain ischemia has not been well established. In the present study, we investigated the chronological alterations of NHE1 in the hippocampal CA1 region using a gerbil model after ischemia/reperfusion. In the sham-operated group, NHE1 immunoreactivity was weakly detected in the CA1 region. Two and 3 days after ischemia/reperfusion, NHE1 immunoreactivity was observed in glial components, not in neurons, in the CA1 region. Four days after ischemia/reperfusion, NHE1 immunoreactivity was markedly increased in CA1 pyramidal neurons as well as glial cells. These glial cells were identified as astrocytes based on double immunofluorescence staining. Western blot analysis also showed that NHE protein level in the CA1 region began to increase 2 days after ischemia/reperfusion. The treatment of 10 mg/kg 5-(N-ethyl-N-isopropyl) amiloride, a NHE inhibitor, significantly reduced the ischemia-induced hyperactivity 1 day after ischemia/reperfusion. In addition, NHE inhibitor potently protected CA1 pyramidal neurons from ischemic damage, and NHE inhibitor attenuated the activation of astrocytes and microglia in the ischemic CA1 region. In addition, NHE inhibitor treatment blocked Na(+)/Ca(2+) exchanger 1 immunoreactivity in the CA1 region after transient forebrain ischemia. These results suggest that NHE1 may play a role in the delayed death, and the treatment with NHE inhibitor protects neurons from ischemic damage.
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http://dx.doi.org/10.1016/j.expneurol.2008.04.007 | DOI Listing |
Commun Biol
January 2025
Applied Mathematics and Computational Biology, IBENS, Ecole Normale Supérieure, PSL University, Paris, France.
Astrocytes form extensive networks with diverse calcium activity, yet the organization and connectivity of these networks across brain regions remain largely unknown. To address this, we developed AstroNet, a data-driven algorithm that uses two-photon calcium imaging to map temporal correlations in astrocyte activation. By organizing individual astrocyte activation events chronologically, our method reconstructs functional networks and extracts local astrocyte correlations.
View Article and Find Full Text PDFNeurobiol Dis
January 2025
Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada. Electronic address:
The consequences of non-pathogenic huntingtin (HTT) reduction in the mature brain are of substantial importance as clinical trials for numerous HTT-lowering therapies are underway; many of which are non-selective in that they reduce both mutant and wild type protein variants. In this study, we injected CaMKII-promoted AAV-Cre directly into the hippocampus of adult HTT floxed mice to explore the role of wild-type huntingtin (wtHTT) in adult hippocampal pyramidal neurons and the broader implications of its loss. Our findings reveal that wtHTT depletion results in profound macroscopic morphological abnormalities in hippocampal structure, accompanied by significant reactive gliosis.
View Article and Find Full Text PDFPLoS Biol
January 2025
Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.
Successful resolution of approach-avoidance conflict (AAC) is fundamentally important for survival, and its dysregulation is a hallmark of many neuropsychiatric disorders, and yet the underlying neural circuit mechanisms are not well elucidated. Converging human and animal research has implicated the anterior/ventral hippocampus (vHPC) as a key node in arbitrating AAC in a region-specific manner. In this study, we sought to target the vHPC CA1 projection pathway to the nucleus accumbens (NAc) to delineate its contribution to AAC decision-making, particularly in the arbitration of learned reward and punishment signals, as well as innate signals.
View Article and Find Full Text PDFNeuromolecular Med
January 2025
Biochemistry and Molecular Biology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221 005, India.
Hypoxia is a significant stressor, and stabilized hypoxia-inducible factor-1α (HIF-1α) regulates the expression of numerous genes, leading to various biochemical, molecular, physiological and genomic changes. The body's oxygen-sensing system activates gene expression to protect brain tissues from hypoxia. Gamma-aminobutyric acid, an inhibitory neurotransmitter, regulates brain excitability during hypoxia through the activation of HIF-1 α.
View Article and Find Full Text PDFDiscov Med
January 2025
Department of Pharmacology "Otto Orsingher", Institute of Experimental Pharmacology of Córdoba (IFEC-CONICET), Faculty of Chemical Sciences, National University of Córdoba, X5000 Córdoba, Argentina.
Background: Angiotensin II, is critical in regulating the sympathetic and neuroendocrine systems through angiotensin II type 1 receptors (AT-R). Angiotensin II intracerebral administration increases water and sodium intake, as well as renal sodium excretion. Previously, our group has shown that AT-R is involved in behavioral and neurochemical sensitization induced by amphetamine.
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