43 research outputs found
Synergistic activity between primary visual neurons
Abstract : Cortical microcircuitry plays a pivotal role in encoding sensory information reaching the
cortex. However, the fundamental knowledge concerning the mechanisms that govern
feature-encoding by these sub-networks is still sparse. Here, we show through multi
electrode recordings in V1 of conventionally prepared anesthetized cats, that an avalanche
of synergistic neural activity occurs between functionally connected neurons in a cell
assembly in response to the presented stimulus. The results specifically show that once the
reference neuron spikes in a connected neuron-pair, it facilitates the response of its
companion (target) neuron for 50 ms and, thereafter, the excitability of the target neuron
declines. On the other hand, the functionally unconnected neurons do not facilitate each
other’s activity within the 50 ms time-window. The added excitation (facilitation) of
connected neurons is almost four times the responsiveness of unconnected neurons. This
suggests that connectedness confers the added excitability to neurons; consequently leading to feature-encoding within the emergent 50 ms-period. Furthermore, the facilitation
significantly decreases as a function of orientation selectivity spread
Interventions to enhance adherence to dietary advice for preventing and managing chronic diseases in adults: a study protocol
Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses
Copyright: © 2015 Sudhakar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNeurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.Peer reviewedFinal Published versio