The spatial and temporal distribution of excitatory and inhibitory membrane potential responses on a cell plays an important role in neuronal calculations in local neuronal circuits in the brain. The electrical dynamics of excitatory and inhibitory inputs along the somatodendritic extent of CA1 pyramidal cells during circuit activation were examined by stimulating strata radiatum (SR), oriens (SO), and lacunosum-moleculare (SLM) and measuring laminar responses with voltage-sensitive dye (VSD) optical recording methods. We first confirmed the linearity of the optical signal by comparing fluorescence changes in CA1 to global membrane potential changes when slices were bathed in high-potassium ([K+](O)=25 mM) solution. Except for a TTX-sensitive component in stratum pyramidale, fluorescence changes were equal in all strata, indicating that VSD sensitivity had reasonable linearity across layers. We then compared membrane potential profiles in slices exposed to picrotoxin, a GABA(A) receptor antagonist. We attributed the picrotoxin-induced changes in the first peak of the excitatory membrane potential to feed-forward inhibition and the later response (appearing 30 ms after stimulation) to feedback inhibition. A difference in feed-forward components was observed in perisomatic and distal apical dendritic regions after SR stimulation. SLM stimulation produced large differences in perisomatic and apical dendritic regions. SO stimulation, however, produced no feed-forward inhibition at the perisomatic region, but produces feed-forward inhibition in distal dendritic regions. These results suggest that actual inhibition of membrane potential response by feed-forward inhibition is greater at perisomatic regions after SR or SLM stimulation but is smaller at distal dendritic regions after SR, SO, and SLM stimulation.
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http://dx.doi.org/10.1016/j.neures.2009.02.007 | DOI Listing |
Acc Chem Res
January 2025
Molecular Sensing and Imaging Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
ConspectusIons are the crucial signaling components for living organisms. In cells, their transportation across pore-forming membrane proteins is vital for regulating physiological functions, such as generating ionic current signals in response to target molecule recognition. This ion transport is affected by confined interactions and local environments within the protein pore.
View Article and Find Full Text PDFBiochem Soc Trans
January 2025
Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud-sección Medicina, Universidad de La Laguna, Tenerife, ES-38071, Spain.
Large conductance voltage- and calcium-activated potassium channels (BK channels) are extensively found throughout the central nervous system and play a crucial role in various neuronal functions. These channels are activated by a combination of cell membrane depolarisation and an increase in intracellular calcium concentration, provided by calcium sources located close to BK. In 2001, Isaacson and Murphy first demonstrated the coupling of BK channels with N-methyl-D-aspartate receptors (NMDAR) in olfactory bulb neurons.
View Article and Find Full Text PDFExtremophiles
January 2025
Microbiology Laboratory, Department of Botany (DST-FIST and UGC-DRS Funded), Institute of Science, Visva-Bharati (A Central University), Santiniketan, West Bengal, 731235, India.
To fish-out novel salt-tolerance genes, metagenomic DNA of moderately saline sediments of India's largest hypersaline Sambhar Lake was cloned in fosmid. Two functionally-picked clones helped the Escherichia coli host to tolerate 0.6 M NaCl.
View Article and Find Full Text PDFBr J Radiol
January 2025
Division of Nuclear Medicine and Molecular Imaging Center, Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Theranostics has its roots with the first radioiodine therapy for thyroid diseases in about 80 years ago. More recently the field has experienced a remarkable renascence with the regulatory approval of paired imaging and radiopharmaceutical therapy agents in gastroenteropancreatic neuroendocrine tumors and metastatic castration-resistant prostate cancer that are now employed in routine clinical practice. The momentum is strong for identification and testing of new theranostic agents for use in various cancers and finding new clinical incications of the available agents.
View Article and Find Full Text PDFPurpose: We hypothesised that applying radiomics to [F]PSMA-1007 PET/CT images could help distinguish Unspecific Bone Uptakes (UBUs) from bone metastases in prostate cancer (PCa) patients. We compared the performance of radiomic features to human visual interpretation.
Materials And Methods: We retrospectively analysed 102 hormone-sensitive PCa patients who underwent [F]PSMA-1007 PET/CT and exhibited at least one focal bone uptake with known clinical follow-up (reference standard).
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