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Cortical Membrane Potential Dynamics and Laminar Firing during Object Motion.

Harvey MA, Valentiniene S, Roland PE - Front Syst Neurosci (2009)

Bottom Line: Complex dynamics evolved including feedback from areas 19/21, the computation of a spatially restricted pre-depolarization (SRP), and firing in the direction of cortical motion prior to the mapping of the bar.After 350 ms, the representations of the bar (peak firing and peak VSD signal) in areas 19/21 and 17/18 moved over the cortex in phase.The dynamics comprise putative mechanisms for automatic saliency of novel moving objects, coherent mapping of moving objects across layers and areas, and planning of catch-up saccades.

View Article: PubMed Central - PubMed

Affiliation: Brain Research, Department of Neuroscience, Karolinska Institute Stockholm, Sweden.

ABSTRACT
When an object is introduced moving in the visual field of view, the object maps with different delays in each of the six cortical layers in many visual areas by mechanisms that are poorly understood. We combined voltage sensitive dye (VSD) recordings with laminar recordings of action potentials in visual areas 17, 18, 19 and 21 in ferrets exposed to stationary and moving bars. At the area 17/18 border a moving bar first elicited an ON response in layer 4 and then ON responses in supragranular and infragranular layers, identical to a stationary bar. Shortly after, the moving bar mapped as moving synchronous peak firing across layers. Complex dynamics evolved including feedback from areas 19/21, the computation of a spatially restricted pre-depolarization (SRP), and firing in the direction of cortical motion prior to the mapping of the bar. After 350 ms, the representations of the bar (peak firing and peak VSD signal) in areas 19/21 and 17/18 moved over the cortex in phase. The dynamics comprise putative mechanisms for automatic saliency of novel moving objects, coherent mapping of moving objects across layers and areas, and planning of catch-up saccades.

No MeSH data available.


Laminar MUA at the retinotopic sites of the appearance of the bar. (A) Laminar local field potentials (left) and CSD (right) in response to a stationary bar presented for 250 ms at the CFOV. Note the sinks in layer IV 30–35 ms after the start of the stimulus and again at 290 ms (OFF response). The white diamonds mark the onset of statistically significant MUA on each lead (p < 0.01, see Materials and Methods). (B–D) Laminar PSTHs, average of 50 trials, filtered with a 10 ms Gaussian temporal filter. S supragranular layers, G granular layer; I infragranular layers of the moving bar starting from the peripheral FOV (B), the stationary bar (C), and the moving bar starting from the CFOV (D). Note similarities in the ON responses.
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Figure 2: Laminar MUA at the retinotopic sites of the appearance of the bar. (A) Laminar local field potentials (left) and CSD (right) in response to a stationary bar presented for 250 ms at the CFOV. Note the sinks in layer IV 30–35 ms after the start of the stimulus and again at 290 ms (OFF response). The white diamonds mark the onset of statistically significant MUA on each lead (p < 0.01, see Materials and Methods). (B–D) Laminar PSTHs, average of 50 trials, filtered with a 10 ms Gaussian temporal filter. S supragranular layers, G granular layer; I infragranular layers of the moving bar starting from the peripheral FOV (B), the stationary bar (C), and the moving bar starting from the CFOV (D). Note similarities in the ON responses.

Mentions: To establish the location of the different layers we estimated the current source density (CSD) from the second spatial derivative of the local field potentials, (Nicholson and Freeman, 1975; Rappelsberger et al., 1981), recorded from our 16 lead laminar probes. For a stationary bar there is an early “sink” in layer 4 reflecting the early input from the thalamocortical axons to the neurons in cortical layer 4, as well as “sources” in the infra and supragranular layers. These sinks and sources are visualized as in Figure 2. The maximal sink was then used as a functional measure of the location of layer 4. The sources were used to indicate the location of the supra and infragranular layers (Mitzdorf and Singer, 1978).


Cortical Membrane Potential Dynamics and Laminar Firing during Object Motion.

Harvey MA, Valentiniene S, Roland PE - Front Syst Neurosci (2009)

Laminar MUA at the retinotopic sites of the appearance of the bar. (A) Laminar local field potentials (left) and CSD (right) in response to a stationary bar presented for 250 ms at the CFOV. Note the sinks in layer IV 30–35 ms after the start of the stimulus and again at 290 ms (OFF response). The white diamonds mark the onset of statistically significant MUA on each lead (p < 0.01, see Materials and Methods). (B–D) Laminar PSTHs, average of 50 trials, filtered with a 10 ms Gaussian temporal filter. S supragranular layers, G granular layer; I infragranular layers of the moving bar starting from the peripheral FOV (B), the stationary bar (C), and the moving bar starting from the CFOV (D). Note similarities in the ON responses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC2742661&req=5

Figure 2: Laminar MUA at the retinotopic sites of the appearance of the bar. (A) Laminar local field potentials (left) and CSD (right) in response to a stationary bar presented for 250 ms at the CFOV. Note the sinks in layer IV 30–35 ms after the start of the stimulus and again at 290 ms (OFF response). The white diamonds mark the onset of statistically significant MUA on each lead (p < 0.01, see Materials and Methods). (B–D) Laminar PSTHs, average of 50 trials, filtered with a 10 ms Gaussian temporal filter. S supragranular layers, G granular layer; I infragranular layers of the moving bar starting from the peripheral FOV (B), the stationary bar (C), and the moving bar starting from the CFOV (D). Note similarities in the ON responses.
Mentions: To establish the location of the different layers we estimated the current source density (CSD) from the second spatial derivative of the local field potentials, (Nicholson and Freeman, 1975; Rappelsberger et al., 1981), recorded from our 16 lead laminar probes. For a stationary bar there is an early “sink” in layer 4 reflecting the early input from the thalamocortical axons to the neurons in cortical layer 4, as well as “sources” in the infra and supragranular layers. These sinks and sources are visualized as in Figure 2. The maximal sink was then used as a functional measure of the location of layer 4. The sources were used to indicate the location of the supra and infragranular layers (Mitzdorf and Singer, 1978).

Bottom Line: Complex dynamics evolved including feedback from areas 19/21, the computation of a spatially restricted pre-depolarization (SRP), and firing in the direction of cortical motion prior to the mapping of the bar.After 350 ms, the representations of the bar (peak firing and peak VSD signal) in areas 19/21 and 17/18 moved over the cortex in phase.The dynamics comprise putative mechanisms for automatic saliency of novel moving objects, coherent mapping of moving objects across layers and areas, and planning of catch-up saccades.

View Article: PubMed Central - PubMed

Affiliation: Brain Research, Department of Neuroscience, Karolinska Institute Stockholm, Sweden.

ABSTRACT
When an object is introduced moving in the visual field of view, the object maps with different delays in each of the six cortical layers in many visual areas by mechanisms that are poorly understood. We combined voltage sensitive dye (VSD) recordings with laminar recordings of action potentials in visual areas 17, 18, 19 and 21 in ferrets exposed to stationary and moving bars. At the area 17/18 border a moving bar first elicited an ON response in layer 4 and then ON responses in supragranular and infragranular layers, identical to a stationary bar. Shortly after, the moving bar mapped as moving synchronous peak firing across layers. Complex dynamics evolved including feedback from areas 19/21, the computation of a spatially restricted pre-depolarization (SRP), and firing in the direction of cortical motion prior to the mapping of the bar. After 350 ms, the representations of the bar (peak firing and peak VSD signal) in areas 19/21 and 17/18 moved over the cortex in phase. The dynamics comprise putative mechanisms for automatic saliency of novel moving objects, coherent mapping of moving objects across layers and areas, and planning of catch-up saccades.

No MeSH data available.