Dynamics of spatial frequency tuning in lateral geniculate nucleus

We present a quantitative analysis of the visual response properties of single neurons in the dorsal lateral geniculate nucleus (dLGN) of wild-type C57Bl/6J mice. Extracellular recordings were made from single dLGN cells in mice under halothane and nitrous oxide anesthesia. After mapping the receptive fields (RFs) of these cells using reverse correlation of responses to flashed square stimuli, we used sinusoidal gratings to describe their linearity of spatial summation, spatial frequency tuning, temporal frequency tuning, and contrast response characteristics. All cells in our sample had RFs dominated by a single, roughly circular “center” mechanism that responded to either increases (on-center) or decreases (off-center) in stimulus luminance, and almost all cells passed a modified null test for linearity of spatial summation. A difference of Gaussians model was used to relate spatial frequency tuning to the spatial properties of cells' RFs, revealing that mouse dLGN cells have large RFs (center diameter approximately 11°) and correspondingly poor spatial resolution (approximately 0.2c/°). Temporally, most cells in the mouse dLGN respond best to stimuli of approximately 4 Hz. We looked for evidence of parallel processing in the mouse dLGN and found it only in a functional difference between on- and off-center cells: on-center cells were more sensitive to stimulus contrast than their off-center neighbors.

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Spatial frequency tuning of orientation-discontinuity-sensitive corticofugal feedback to the cat lateral geniculate nucleus.

The Journal of Physiology ◽

10.1113/jphysiol.1996.sp021159 ◽

1996 ◽

Vol 490 (2) ◽

pp. 481-492 ◽

Cited By ~ 65

Author(s):

J Cudeiro ◽

A M Sillito

Keyword(s):

Spatial Frequency ◽

Lateral Geniculate Nucleus ◽

Frequency Tuning ◽

Spatial Frequency Tuning ◽

Lateral Geniculate ◽

Corticofugal Feedback

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Contrast-Dependent Spatial Summation in the Lateral Geniculate Nucleus and Retina of the Cat

Journal of Neurophysiology ◽

10.1152/jn.00176.2004 ◽

2004 ◽

Vol 92 (3) ◽

pp. 1708-1717 ◽

Cited By ~ 37

Author(s):

M. J. Nolt ◽

R. D. Kumbhani ◽

L. A. Palmer

Keyword(s):

Spatial Frequency ◽

Lateral Geniculate Nucleus ◽

Frequency Tuning ◽

Ganglion Cells ◽

Receptive Fields ◽

Spatial Summation ◽

Cell Types ◽

Retinal Ganglion ◽

Difference Of Gaussians ◽

Lateral Geniculate

Based on extracellular recordings from 69 lateral geniculate nucleus (LGN) cells in the anesthetized cat, we found spatial summation within their receptive fields to be dependent on the contrast of the stimuli presented. By fitting the summation curves to a difference of Gaussians model, we attributed this contrast-dependent effect to an actual change in the size of the center mechanism. Analogous changes in spatial frequency tuning were also observed, specifically increased peaks and cut-off frequencies with contrast. These effects were seen across the populations of both X and Y cell types. In a few cases, LGN cells were recorded simultaneously with one of their retinal ganglion cell (RGC) inputs (S-potentials). In every case, the RGCs exhibited similar contrast-dependent effects in the space and spatial-frequency domains. We propose that this contrast dependency in the retinal ganglion cells results directly from a reduction in the size of the center mechanism due to an increase in contrast. We also propose that these properties first arise in the retina and are transmitted passively through the LGN to visual cortex.

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Adaptation in single units in visual cortex: The tuning of aftereffects in the spatial domain

Visual Neuroscience ◽

10.1017/s0952523800003527 ◽

1989 ◽

Vol 2 (6) ◽

pp. 593-607 ◽

Cited By ~ 65

Author(s):

A. B. Saul ◽

M. S. Cynader

Keyword(s):

Spatial Frequency ◽

Cortical Neurons ◽

Frequency Tuning ◽

Cortical Cell ◽

Selective Adaptation ◽

Single Units ◽

Spatial Frequency Tuning ◽

Sinusoidal Gratings ◽

A Cell ◽

Drift Direction

AbstractCat striate cortical neurons were investigated using a new method of studying adaptation aftereffects. Stimuli were sinusoidal gratings of variable contrast, spatial frequency, and drift direction and rate. A series of alternating adapting and test trials was presented while recording from single units. Control trials were completely integrated with the adapted trials in these experiments.Every cortical cell tested showed selective adaptation aftereffects. Adapting at suprathreshold contrasts invariably reduced contrast sensitivity. Significant aftereffects could be observed even when adapting at low contrasts.The spatial-frequency tuning of aftereffects varied from cell to cell. Adapting at a given spatial frequency generally resulted in a broad response reduction at test frequencies above and below the adapting frequency. Many cells lost responses predominantly at frequencies lower than the adapting frequency.The tuning of aftereffects varied with the adapting frequency. In particular, the strongest aftereffects occurred near the adapting frequency. Adapting at frequencies just above the optimum for a cell often altered the spatial-frequency tuning by shifting the peak toward lower frequencies. The fact that the tuning of aftereffects did not simply match the tuning of the cell, but depended on the adapting stimulus, implies that extrinsic mechanisms are involved in adaptation effects.

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