Ion-concentration gradients induced by synaptic input increase the voltage depolarization in dendritic spines

Journal of Computational Neuroscience, Journal Year: 2024, Volume and Issue: 52(1), P. 1 - 19

Published: Feb. 1, 2024

Abstract The vast majority of excitatory synaptic connections occur on dendritic spines. Due to their extremely small volume and spatial segregation from the dendrite, even moderate currents can significantly alter ionic concentrations. This results in chemical potential gradients between dendrite spine head, leading measurable electrical currents. In modeling electric signals spines, different formalisms were previously used. While cable equation is fundamental for understanding along dendrites, it only considers as a result potential. Poisson-Nernst-Planck (PNP) equations offer more accurate description spines by incorporating both However, solving PNP computationally complex. this work, diffusion are incorporated into equation, leveraging an analogy For simulating based extension straightforward numerical solver introduced. study demonstrates that set be accurately solved using explicit finite difference scheme. Through simulations, unveils unrecognized mechanism involving amplify discovery holds crucial implications simulations experimental studies focused neck resistance calcium signaling

Language: Английский

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How neuronal morphology impacts the synchronisation state of neuronal networks

PLoS Computational Biology, Journal Year: 2024, Volume and Issue: 20(3), P. e1011874 - e1011874

Published: March 4, 2024

The biophysical properties of neurons not only affect how information is processed within cells, they can also impact the dynamical states network. Specifically, cellular dynamics action-potential generation have shown relevance for setting (de)synchronisation state tonically spiking typically fall into one three qualitatively distinct types that arise from mathematical bifurcations voltage at onset spiking. Accordingly, changes in ion channel composition or even external factors, like temperature, been demonstrated to switch network behaviour via spike bifurcation and hence its associated type. A thus far less addressed modulator neuronal morphology. Based on simplified anatomically realistic neuron models, we show here extent dendritic arborisation has an influence type therefore larger trees prime in-phase-synchronised splayed-out activity weakly coupled networks, contrast cells with otherwise identical yet smaller dendrites. Our insights hold generic multicompartmental classes models (from ball-and-stick-type reconstructed models) establish a connection between morphology susceptibility neural tissue synchronisation health disease.

Language: Английский

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A dendrite is a dendrite is a dendrite? Dendritic signal integration beyond the “antenna” model

Pflügers Archiv - European Journal of Physiology, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 9, 2024

Neurons in central nervous systems receive multiple synaptic inputs and transform them into a largely standardized output to their target cells-the action potential. A simplified model posits that signals are integrated by linear summation passive propagation towards the axon initial segment, where threshold for spike generation is either crossed or not. However, lines of research during past decades have shown signal integration individual neurons much more complex, with important functional consequences at cellular, network, behavioral-cognitive level. The interplay between concomitant excitatory inhibitory postsynaptic potentials depends strongly on relative timing localization respective synapses. In addition, dendrites contain voltage-dependent conductances, which allow scaling potentials, non-linear input processing, compartmentalization signals. Together, these features enable rich variety single-neuron computations, including operations plasticity. Hence, we revise over-simplified messages from textbooks use computational models like integrate-and-fire some caution. This concept article summarizes most mechanisms dendritic highlights recent developments field.

Language: Английский

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Phenomenological Modeling of Diverse and Heterogeneous Synaptic Dynamics at Natural Density

Neuromethods, Journal Year: 2024, Volume and Issue: unknown, P. 277 - 321

Published: Jan. 1, 2024

Language: Английский

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Supralinear dendritic integration in murine dendrite-targeting interneurons

eLife, Journal Year: 2024, Volume and Issue: 13

Published: Sept. 16, 2024

Non-linear summation of synaptic inputs to the dendrites pyramidal neurons has been proposed increase computation capacity through coincidence detection, signal amplification, and additional logic operations such as XOR. Supralinear dendritic integration documented extensively in principal neurons, mediated by several voltage-dependent conductances. It also reported parvalbumin-positive hippocampal basket cells, innervated feedback excitatory synapses. Whether other interneurons, which support feed-forward or inhibition neuron dendrites, exhibit local non-linear excitation is not known. Here, we use patch-clamp electrophysiology, two-photon calcium imaging glutamate uncaging, show that supralinear near-synchronous spatially clustered glutamate-receptor depolarization occurs NDNF-positive neurogliaform cells oriens-lacunosum moleculare interneurons mouse hippocampus. was detected via recordings somatic depolarizations elicited uncaging on fragments, and, concurrent transients. Supralinearity abolished blocking NMDA receptors (NMDARs) but resisted blockade voltage-gated sodium channels. Blocking L-type channels signalling only had a minor effect voltage supralinearity. Dendritic boosting signals argues for previously unappreciated computational complexity dendrite-projecting inhibitory

Language: Английский

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