1 Asymmetric Temporal Integration of 2 Layer 4 and Layer 2 / 3 Inputs in Visual Cortex
نویسنده
چکیده
21 Neocortical neurons in vivo receive concurrent synaptic inputs from multiple sources, 22 including feedforward, horizontal, and feedback pathways. Layer 2/3 of the visual cortex 23 receives feedforward input from layer 4 and horizontal input from layer 2/3. Firing of the 24 pyramidal neurons, which carries the output to higher cortical areas, depends critically 25 on the interaction of these pathways. Here we examined synaptic integration of inputs 26 from layer 4 and layer 2/3 in rat visual cortical slices. We found that the integration is 27 sublinear and temporally asymmetric, with larger responses if layer 2/3 input preceded 28 layer 4 input. The sublinearity depended on inhibition, and the asymmetry was largely 29 attributable to the difference between the two inhibitory inputs. Interestingly, the 30 asymmetric integration was specific to pyramidal neurons, and it strongly affected their 31 spiking output. Thus, via cortical inhibition, the temporal order of activation of layer 2/3 32 and layer 4 pathways can exert powerful control of cortical output during visual 33 processing. 34 35
منابع مشابه
Asymmetric temporal integration of layer 4 and layer 2/3 inputs in visual cortex.
Neocortical neurons in vivo receive concurrent synaptic inputs from multiple sources, including feedforward, horizontal, and feedback pathways. Layer 2/3 of the visual cortex receives feedforward input from layer 4 and horizontal input from layer 2/3. Firing of the pyramidal neurons, which carries the output to higher cortical areas, depends critically on the interaction of these pathways. Here...
متن کاملLayer-specific network oscillation and spatiotemporal receptive field in the visual cortex.
A quintessential feature of the neocortex is its laminar organization, and characterizing the activity patterns in different layers is an important step in understanding cortical processing. Using in vivo whole-cell recordings in rat visual cortex, we show that the temporal patterns of ongoing synaptic inputs to pyramidal neurons exhibit clear laminar specificity. Although low-frequency (approx...
متن کاملPrimed-burst potentiation in adult rat visual cortex in vitro
The effectiveness of θ pattern primed-bursts (PBs) on development of primed-burst (PB) potentiation was investigated in layer II/III of the adult rat visual cortex in vitro. Experiments were carried out in the visual cortical slices. Population excitatory post-synaptic potentials (pEPSPs) were evoked in layer II/III by stimulation of either white mater or layer IV. To induce long-term potenti...
متن کاملCellular mechanisms of temporal sensitivity in visual cortex neurons.
The ability of cortical neurons to accurately encode the temporal pattern of their inputs has important consequences for cortical function and perceptual acuity. Here we identify cellular mechanisms underlying the sensitivity of cortical neurons to the timing of sensory-evoked synaptic inputs. We find that temporally coincident inputs to layer 4 neurons in primary visual cortex evoke an increas...
متن کاملDistinct GABAergic targets of feedforward and feedback connections between lower and higher areas of rat visual cortex.
Processing of visual information is performed in different cortical areas that are interconnected by feedforward (FF) and feedback (FB) pathways. Although FF and FB inputs are excitatory, their influences on pyramidal neurons also depend on the outputs of GABAergic neurons, which receive FF and FB inputs. Rat visual cortex contains at least three different families of GABAergic neurons that exp...
متن کامل