Temporal integration and 1/f power scaling in a circuit model of cerebellar interneurons

This document is the Accepted Manuscript version of a published work that appeared in final form in Journal of Neurophysiology after peer review and technical editing by the publisher. Under embargo until 1 July 2018. To access the final edited and published work see: https://doi.org/10.1152/jn.00789.2016.Inhibitory interneurons interconnected via electrical and chemical (GABAA receptor) synapses form extensive circuits in several brain regions. They are thought to be involved in timing and synchronization through fast feedforward control of principal neurons. Theoretical studies have shown, however, that whereas self-inhibition does indeed reduce response duration, lateral inhibition, in contrast, may generate slow response components through a process of gradual disinhibition. Here we simulated a circuit of interneurons (stellate and basket cells) of the molecular layer of the cerebellar cortex and observed circuit time constants that could rise, depending on parameter values, to >1 s. The integration time scaled both with the strength of inhibition, vanishing completely when inhibition was blocked, and with the average connection distance, which determined the balance between lateral and self-inhibition. Electrical synapses could further enhance the integration time by limiting heterogeneity among the interneurons and by introducing a slow capacitive current. The model can explain several observations, such as the slow time course of OFF-beam inhibition, the phase lag of interneurons during vestibular rotation, or the phase lead of Purkinje cells. Interestingly, the interneuron spike trains displayed power that scaled approximately as 1/f at low frequencies. In conclusion, stellate and basket cells in cerebellar cortex, and interneuron circuits in general, may not only provide fast inhibition to principal cells but also act as temporal integrators that build a very short-term memory.NEW & NOTEWORTHY The most common function attributed to inhibitory interneurons is feedforward control of principal neurons. In many brain regions, however, the interneurons are densely interconnected via both chemical and electrical synapses but the function of this coupling is largely unknown. Based on large-scale simulations of an interneuron circuit of cerebellar cortex, we propose that this coupling enhances the integration time constant, and hence the memory trace, of the circuit.Peer reviewe

Spectral changes of brain activity in rat offspring exposed to aluminium during gestation and lactation

Exposure to aluminium during gestation causes changes in mammalian brain development and behavior. Our aim was to perform spectral analysis on electrocortical activity of Sprague Dawley male pups (30±3 days of age) whose mothers were treated with aluminium during gestation and lactation. There was a higher presence of power spectra in the delta range of parietal electrocortical activity, a lower presence in the theta range and increased values of the parameter DT as the ratio of delta to theta range in pups indirectly exposed to aluminium (whose mothers were drinking a 0.5% water solution of aluminium chloride during the gestation and lactation periods), compared to controls

On the neutron scattering on large polarons in quasi-one-dimensional molecular crystals

The possible large-polaron contribution to the neutron scattering on quasi-one-dimensional molecular crystals was examined within the continuum polaron model. It was found that the appearance of the central peak in the dynamic structure factor should be expected if large-polaron formation takes place. The possibility of the experimental verification of the existence of Davydov-like solitons in biological systems was discussed on the basis of these predictions

Le Grand écho du Nord de la France

30 janvier 19071907/01/30 (A89,N30).Appartient à l’ensemble documentaire : NordPdeC

Quantum foundations of resonant recognition model

Biomolecular recognition is open scientific problem, which has been investigated in many theoretical and experimental aspects. In that sense, there are encouraging results within Resonant Recognition Model (RRM), which is based on theory of information spectrum of macromolecules. The RRM concept is based on the finding that there is a significant correlation between spectra of the numerical presentation of amino acids in the primary structure of proteins and their biological activity. It has been found through an extensive research that proteins with the same biological function have a common RRM peak (wavenumber) in their numerical spectra, correlated to EM peak (frequency) by semi-empirical dispersion relation. This peak was found then to be a characteristic feature for protein biological function or interaction. The RRM model proposes that the selectivity of protein-target interactions is based on resonant energy transfer between interacting biomolecules and that this energy, EM in its nature, is in the frequency range of 1013 to 1015 Hz, which incorporates infra-red (IR), visible and a small portion of the ultra-violet (UV) radiation. In this paper, the quantum mechanical basis of the RRM model will be investigated using the solution in the simplified framework of Hückel-like theory of molecular orbits

Quantum decoherence and quantum-holographic information processes: From biomolecules to biosystems

Our recently proposed quantum approach to biomolecular recognition processes is hereby additionally supported by biomolecular Resonant Recognition Model and by quantum-chemical theory of biomolecular non-radiative resonant transitions. Previously developed general quantum-decoherence framework for biopolymer conformational changes in very selective ligand-proteins/target-receptors key/lock biomolecular recognition processes (with electron-conformational coupling, giving rise to dynamical modification of many-electron energy-state hypersurface of the cellular quantum-ensemble ligand-proteins/target-receptors biomolecular macroscopic quantum system, with revealed possibility to consider cellular biomolecular recognition as a Hopfield-like quantum-holographic associative neural network) is further extended from nonlocal macroscopic-quantum level of biological cell to nonlocal macroscopic-quantum level of biological organism, based on long-range coherent microwave excitations (as supported by macroscopic quantum-like microwave resonance therapy of the acupuncture system) - which might be of fundamental importance in understanding of underlying macroscopic quantum (quantum-holographic Hopfield-like) control mechanisms of embryogenesis/ontogenesis and morphogenesis, and their backward influence on the expression of genes.Recent Developments in Advanced Materials and Processes, 7th Conference of the Yugoslav-Materials-Research-Society (Yu-MRS), Sep 12-16, 2005, Herceg Novi, Montenegr