Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
eNeuro ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38997146

ABSTRACT

It has long been assumed that activity patterns persist in neuronal circuits after they are first experienced, as part of the process of information processing and storage by the brain. However, these "reverberations" of current activity have not been directly observed on a single neuron level in a mammalian system. Here we demonstrate that specific induced activity patterns are retained in mature cultured hippocampal neuronal networks. Neurons within the network are induced to fire at a single frequency or in a more complex pattern containing two distinct frequencies. After the stimulation was stopped, the subsequent neuronal activity of hundreds of neurons in the network was monitored. In the case of single-frequency stimulation, it was observed that many of the neurons continue to fire at the same frequency that they were stimulated to fire at. Using a Recurrent Neural Network (RNN) trained to detect specific, more complex patterns, we found that the multiple-frequency stimulation patterns were also retained within the neuronal network. Moreover, it appears that the component frequencies of the more complex patterns are stored in different populations of neurons and neuron subtypes.Significance Statement The existence of memory engrams, or reverberations of recently experienced activity patterns, has long been supposed but never directly demonstrated in mammalian neuronal networks. Through the use of highly accessible cultured neuronal networks grown on silicon wafers, stimulated to fire in user-defined patterns using photoconductive stimulation, we have demonstrated their existence and established a paradigm for the analysis of the microcircuitry involved.

2.
Neuroscience ; 376: 204-223, 2018 04 15.
Article in English | MEDLINE | ID: mdl-29555037

ABSTRACT

Collapsin Response Mediator Protein 2 (CRMP2) is an intracellular protein involved in axon and dendrite growth and specification. In this study, CRMP2 was identified in a conditioned media derived from degenerated sciatic nerves (CM). On cultured rat hippocampal neurons, acute extracellular application of CM or partially purified recombinant CRMP2 produced an increase in cytoplasmic calcium. The increase in cytoplasmic calcium was mostly mediated through NMDA receptors, with a minor contribution of N-type VDCC, and it was maintained as long as CM was present. By using live-labeling of CRMP2, Ca2+ channel binding domain 3 (CBD3) peptide derived from CRMP2, and recombinant CRMP2, we demonstrated that that this effect was mediated by an action on the extracellular side of the NMDA receptor. This is the first report of an extracellular action of CRMP2. Prolonged exposure to extracellular CRMP2, may contribute to neuronal calcium dysregulation and neuronal damage.


Subject(s)
Calcium/metabolism , Central Nervous System Agents/administration & dosage , Cytoplasm/drug effects , Intercellular Signaling Peptides and Proteins/administration & dosage , Nerve Tissue Proteins/administration & dosage , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Cations, Divalent/metabolism , Cells, Cultured , Central Nervous System Agents/isolation & purification , Culture Media, Conditioned , Cytoplasm/metabolism , Extracellular Space , Hippocampus/drug effects , Hippocampus/metabolism , Male , Mice , Molecular Docking Simulation , Nerve Tissue Proteins/isolation & purification , Nerve Tissue Proteins/metabolism , Neurons/drug effects , Neurons/metabolism , Optic Nerve/metabolism , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Recombinant Proteins/administration & dosage , Sciatic Nerve/metabolism
3.
Brain Res ; 1110(1): 64-75, 2006 Sep 19.
Article in English | MEDLINE | ID: mdl-16859657

ABSTRACT

Neuregulin-1 (NRG-1) is an active component found in sciatic nerve conditioned medium (CM). NRG-1 is a growth and differentiation factor shown to have an effect on neuritogenesis and survival of neural cells. PC12 cells chronically treated with NRG-1 (beta1 isoform) show an increase in proliferation under low-serum condition (2.5% fetal bovine serum and 1.25% horse serum) and serum deprivation, without visible morphological changes. NRG-1 and CM treatments of PC12 cells induced an increase of voltage-activated Ca2+ currents and large-conductance calcium-activated K+ currents (KCa). AG825, a specific inhibitor for erbB2 receptor, abolishes KCa current, though Ca2+ currents were not inhibited. These results showed that NRG-1 is capable of inducing functional changes but is not sufficient on its own to have an effect on cell morphology.


Subject(s)
Calcium Channels/physiology , Cell Proliferation/drug effects , Neuregulin-1/pharmacology , PC12 Cells/drug effects , Potassium Channels, Calcium-Activated/physiology , Analysis of Variance , Animals , Benzothiazoles/pharmacology , Cell Differentiation/drug effects , Charybdotoxin/pharmacology , Culture Media, Conditioned/pharmacology , Culture Media, Serum-Free/pharmacology , Dose-Response Relationship, Drug , Drug Interactions , Electric Stimulation/methods , Glycoproteins/genetics , Glycoproteins/metabolism , Humans , Iodobenzenes/pharmacology , Neurotoxins/pharmacology , Patch-Clamp Techniques/methods , Protein Isoforms/pharmacology , Rats , Receptor, ErbB-2 , Sciatic Nerve/chemistry , Tyrphostins/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...