Field recordings from the dentate granule cell layer of in vitro brain slices of temporal lobe epileptic patients were evoked by antidromic stimulation. Tissue from the same specimen was stained by the Timm-sulfide method to assess the pattern and degree of mossy fiber reorganization into the supragranular layer. A wide range of physiological responses and Timm staining patterns was present across patients. A significant correlation was observed between the abnormality of antidromic responses, reflected by multiple secondary population spikes, and the degree of Timm staining of the supragranular layer. This relationship lends support to the hypothesis that mossy fiber synapses located in the supragranular layer may have functional implications for granule cell excitability in human epileptic tissue.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0006-8993(92)90750-4 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The hippocampus forms memories of our experiences by registering processed sensory information in coactive populations of excitatory principal cells or ensembles. Fast-spiking parvalbumin-expressing inhibitory neurons (PV INs) in the dentate gyrus (DG)-CA3/CA2 circuit contribute to memory encoding by exerting precise temporal control of excitatory principal cell activity through mossy fiber-dependent feed-forward inhibition. PV INs respond to input-specific information by coordinating changes in their intrinsic excitability, input-output synaptic-connectivity, synaptic-physiology and synaptic-plasticity, referred to here as experience-dependent PV IN plasticity, to influence hippocampal functions.
View Article and Find Full Text PDFEffects of MeCP2 on chronic seizures and cognitive function in mice with temporal lobe epilepsy.
Epilepsy Res
January 2025
Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China. Electronic address:
Mutations in methyl CpG binding protein 2 (MeCP2) are linked to Rett syndrome, in which epilepsy is one of the most well-described disorders. However, little is known about the specific role of MeCP2 during epileptogenesis. Our previous study has demonstrated that MeCP2 has a unique control on the development of mossy fiber sprouting (MFS) in the epileptic hippocampus.
View Article and Find Full Text PDFModeling analysis of depolarization-assisted afterdischarge in hippocampal mossy fibers.
Front Neural Circuits
January 2025
Department of Neurobiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
A strong repetitive stimulus can occasionally enhance axonal excitability, leading to the generation of afterdischarge. This afterdischarge outlasts the stimulus period and originates either from the physiological spike initiation site, typically the axon initial segment, or from ectopic sites for spike generation. One of the possible mechanisms underlying the stimulus-induced ectopic afterdischarge is the local depolarization due to accumulated potassium ions surrounding the axonal membranes of the distal portion.
View Article and Find Full Text PDFRealistic mossy fiber input patterns to unipolar brush cells evoke a continuum of temporal responses comprised of components mediated by different glutamate receptors.
Elife
January 2025
Department of Neurobiology, Harvard Medical School, Boston, United States.
Unipolar brush cells (UBCs) are excitatory interneurons in the cerebellar cortex that receive mossy fiber (MF) inputs and excite granule cells. The UBC population responds to brief burst activation of MFs with a continuum of temporal transformations, but it is not known how UBCs transform the diverse range of MF input patterns that occur in vivo. Here, we use cell-attached recordings from UBCs in acute cerebellar slices to examine responses to MF firing patterns that are based on in vivo recordings.
View Article and Find Full Text PDFFast Neuronal Calcium Signals in Brain Slices Loaded With Fluo-4 AM Ester.
Eur J Neurosci
January 2025
Université Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
Staining brain slices with acetoxymethyl ester (AM) Ca dyes is a straightforward procedure to load multiple cells, and Fluo-4 is a commonly used high-affinity indicator due to its very large dynamic range. It has been shown that this dye preferentially stains glial cells, providing slow and large Ca transients, but it is questionable whether and at which temporal resolution it can also report Ca transients from neuronal cells. Here, by electrically stimulating mouse hippocampal slices, we resolved fast neuronal signals corresponding to 1%-3% maximal fluorescence changes.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!