Whisker row deprivation affects the flow of sensory information through rat barrel cortex

Abstract

Sensory cortical plasticity is usually quantified by changes in evoked firing rate. In this study we quantified plasticity by changes in sensory detection performance using Chernoff information and receiver operating characteristic analysis. We found that whisker deprivation causes a change in information flow within the cortical layers and that layer 5 regular-spiking cells, despite showing only a small potentiation of short-latency input, show the greatest increase in information content for the spared input partly by decreasing their spontaneous activity.

Time-course and mechanisms of homeostatic plasticity in layers 2/3 and 5 of the barrel cortex

“…It is not clear at present why such a mechanism would differ between L5RS cells compared with L5IB cells. However, it does give RS cells an adaptive advantage because the signal to noise ratio increases for L5RS cells [62] through a homeostatic response to sensory inputs and a lack of firing rate homeostasis. In this way, the L5RS cells achieve a similar result to the L5IB cells that do show firing rate homeostasis, but IB cells require a CaMKII-dependent mechanism to potentiate their spared whisker input beyond baseline [24] to achieve an increase in signal to noise ratio [62].…”

Deconstructing the Cortical Column in the Barrel Cortex

“…In this case the two conditions are stimulus versus no stimulus. Using this method, layer 2/3 and layer 4 cells show almost identical ROC followed by lower values in layer 5 (Jacob et al, 2017). As discussed in the following sections, the information content in layer 5 neurons can be further subdivided by neuron type and can also be modified under conditions that induce experience-dependent plasticity, which change the relative information content in supra-and infragranular cortex.…”

“…those below 10 ms), which suggests that the layer 2/3 excitatory input to layer 5 is more likely to act by sustaining the responses of layer 5 cells. Layer 5 intrinsic bursting (IB) cells, (which are a subset of layer 5 cells with intrinsic membrane properties leading to bursts of spikesvide infra), exhibit EPSPs lasting more than 50 ms after the stimulus onset and can produce action potentials 30-40 ms after the stimulus onset (Jacob et al, 2017). Layer 2/3 cells therefore respond to principal whisker stimulation in sufficient time to influence the output of layer 5 IB cells.…”

“…Information about the stimulus can be determined during the time evolution of the neuronal response by considering the Chernoff information in short intervals (1-ms bins) and integrating the information with time (Jacob et al, 2017). By this measure, the greatest information about the principal whisker is present in layer 4 neurons, closely followed by the layer 2/3 neurons and lower values are present for the layer 5 neurons (Jacob et al, 2017).…”

“…Information about the stimulus can be determined during the time evolution of the neuronal response by considering the Chernoff information in short intervals (1-ms bins) and integrating the information with time (Jacob et al, 2017). By this measure, the greatest information about the principal whisker is present in layer 4 neurons, closely followed by the layer 2/3 neurons and lower values are present for the layer 5 neurons (Jacob et al, 2017). This broadly follows the canonical view of information processing within the cortical columns of the visual cortex from layer 4 to layer 3 to layer 5 as envisaged by Gilbert and Wiesel (1983) and discussed by Douglas and Martin (2004).…”