Diverse receptive fields in the lateral geniculate nucleus during thalamocortical development

10.1038/75786 ◽  
2000 ◽  
Vol 3 (6) ◽  
pp. 608-616 ◽  
Author(s):  
Sohail F. Tavazoie ◽  
R. Clay Reid
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Receptive Fields ◽  
Lateral Geniculate

Spatial limits of epileptogenic cortex: its relationship to ectopic spike generation

1975 ◽  
Vol 38 (2) ◽  
pp. 395-404 ◽  
Author(s):  
A. J. Gabor ◽  
R. P. Scobey
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Direct Effect ◽  
Receptive Fields ◽  
Spike Generation ◽  
Lateral Geniculate

In order to investigate if ectopic spike generation was ubiquitous in and specific generation was ubiquitous in and specific to epileptogenic cortex, a method was devised to determine the limits of such an area based on a well-accepted physiologic characteristic of epileptogenicity. The limits of the penicillin-induced epileptogenic cortex were defined in terms of a retinal activation field; this is a circumscribed area whose stimulation by light evokes a characteristic cortical epileptiform wave. All lateral geniculate nucleus (LGN) neurons manifesting ectopic spike generation during interictal epileptiform waves had receptive fields within the activation field. During organized seizures, ectopic spike generation was observed in neurons with receptive fields outside the activation field. Because of these findings it was concluded that ectopic spike generation is a characteristic and specific feature of epileptogenic cortex and that it is a characteristic of the epeleptogenic process rather than a peripheral event related entirely to the direct effect of penicillin on neurons.

Mathematical models for the spatial receptive-field organization of nonlagged X-cells in dorsal lateral geniculate nucleus of cat

2000 ◽  
Vol 17 (6) ◽  
pp. 871-885 ◽  
Author(s):  
G.T. EINEVOLL ◽  
P. HEGGELUND
Keyword(s):  
Receptive Field ◽  
Ganglion Cell ◽  
Lateral Geniculate Nucleus ◽  
Discrete Model ◽  
Receptive Fields ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Retinal Ganglion ◽  
Lateral Geniculate ◽  
X Cells ◽  
Dorsal Lateral Geniculate

Spatial receptive fields of relay cells in dorsal lateral geniculate nucleus (dLGN) have commonly been modeled as a difference of two Gaussian functions. We present alternative models for dLGN cells which take known physiological couplings between retina and dLGN and within dLGN into account. The models include excitatory input from a single retinal ganglion cell and feedforward inhibition via intrageniculate interneurons. Mathematical formulas describing the receptive field and response to circular spot stimuli are found both for models with a finite and an infinite number of ganglion-cell inputs to dLGN neurons. The advantage of these models compared to the common difference-of-Gaussians model is that they, in addition to providing mathematical descriptions of the receptive fields of dLGN neurons, also make explicit contributions from the geniculate circuit. Moreover, the model parameters have direct physiological relevance and can be manipulated and measured experimentally. The discrete model is applied to recently published data (Ruksenas et al., 2000) on response versus spot-diameter curves for dLGN cells and for the retinal input to the cell (S-potentials). The models are found to account well for the results for the X-cells in these experiments. Moreover, predictions from the discrete model regarding receptive-field sizes of interneurons, the amount of center-surround antagonism for interneurons compared to relay cells, and distance between neighboring retinal ganglion cells providing input to interneurons, are all compatible with data available in the literature.

scholarly journals Spatial receptive fields in the retina and dorsal lateral geniculate nucleus of mice lacking rods and cones

2015 ◽  
Vol 114 (2) ◽  
pp. 1321-1330 ◽  
Author(s):  
Christopher A. Procyk ◽  
Cyril G. Eleftheriou ◽  
Riccardo Storchi ◽  
Annette E. Allen ◽  
Nina Milosavljevic ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Lateral Geniculate Nucleus ◽  
Visual Information ◽  
Spatial Information ◽  
Receptive Fields ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Multielectrode Arrays ◽  
Rods And Cones ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

In advanced retinal degeneration loss of rods and cones leaves melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) as the only source of visual information. ipRGCs drive non-image-forming responses (e.g., circadian photoentrainment) under such conditions but, despite projecting to the primary visual thalamus [dorsal lateral geniculate nucleus (dLGN)], do not support form vision. We wished to determine what precludes ipRGCs supporting spatial discrimination after photoreceptor loss, using a mouse model ( rd/rd cl) lacking rods and cones. Using multielectrode arrays, we found that both RGCs and neurons in the dLGN of this animal have clearly delineated spatial receptive fields. In the retina, they are typically symmetrical, lack inhibitory surrounds, and have diameters in the range of 10–30° of visual space. Receptive fields in the dLGN were larger (diameters typically 30–70°) but matched the retinotopic map of the mouse dLGN. Injections of a neuroanatomical tracer (cholera toxin β-subunit) into the dLGN confirmed that retinotopic order of ganglion cell projections to the dLGN and thalamic projections to the cortex is at least superficially intact in rd/rd cl mice. However, as previously reported for deafferented ipRGCs, onset and offset of light responses have long latencies in the rd/rd cl retina and dLGN. Accordingly, dLGN neurons failed to track dynamic changes in light intensity in this animal. Our data reveal that ipRGCs can convey spatial information in advanced retinal degeneration and identify their poor temporal fidelity as the major limitation in their ability to provide information about spatial patterns under natural viewing conditions.

Temporal response properties of koniocellular (blue-on and blue-off) cells in marmoset lateral geniculate nucleus

2014 ◽  
Vol 112 (6) ◽  
pp. 1421-1438 ◽  
Author(s):  
A. N. J. Pietersen ◽  
S. K. Cheong ◽  
S. G. Solomon ◽  
C. Tailby ◽  
P. R. Martin
Keyword(s):  
Color Vision ◽  
Lateral Geniculate Nucleus ◽  
Receptive Fields ◽  
Visual Signals ◽  
Cortical Circuits ◽  
Temporal Response ◽  
Lateral Geniculate ◽  
Visual Latency ◽  
Cell Groups ◽  
Bon Cells

Visual perception requires integrating signals arriving at different times from parallel visual streams. For example, signals carried on the phasic-magnocellular (MC) pathway reach the cerebral cortex pathways some tens of milliseconds before signals traveling on the tonic-parvocellular (PC) pathway. Visual latencies of cells in the koniocellular (KC) pathway have not been specifically studied in simian primates. Here we compared MC and PC cells to “blue-on” (BON) and “blue-off” (BOF) KC cells; these cells carry visual signals originating in short-wavelength-sensitive (S) cones. We made extracellular recordings in the lateral geniculate nucleus (LGN) of anesthetized marmosets. We found that BON visual latencies are 10–20 ms longer than those of PC or MC cells. A small number of recorded BOF cells ( n = 7) had latencies 10–20 ms longer than those of BON cells. Within all cell groups, latencies of foveal receptive fields (<10° eccentricity) were longer (by 3–8 ms) than latencies of peripheral receptive fields (>10°). Latencies of yellow-off inputs to BON cells lagged the blue-on inputs by up to 30 ms, but no differences in visual latency were seen on comparing marmosets expressing dichromatic (“red-green color-blind”) or trichromatic color vision phenotype. We conclude that S-cone signals leaving the LGN on KC pathways are delayed with respect to signals traveling on PC and MC pathways. Cortical circuits serving color vision must therefore integrate across delays in (red-green) chromatic signals carried by PC cells and (blue-yellow) signals carried by KC cells.

Quantitative analyses of synaptic contacts of interneurons in the dorsal lateral geniculate nucleus of the squirrel monkey

1996 ◽  
Vol 13 (6) ◽  
pp. 1129-1142 ◽  
Author(s):  
James R. Wilson ◽  
Donna M. Forestner ◽  
Ryan P. Cramer
Keyword(s):  
Squirrel Monkey ◽  
Lateral Geniculate Nucleus ◽  
Receptive Fields ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Saimiri Sciureus ◽  
Projection Neurons ◽  
Parvocellular Pathway ◽  
Synaptic Contacts ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

AbstractThree interneurons were recorded from and then injected with horseradish peroxidase in the parvocellular laminae of the squirrel monkey's (Saimiri sciureus) dorsal lateral geniculate nucleus. They were then examined using the electron microscope for their synaptic contacts, both the afferent contacts onto their dendrites and their presynaptic dendritic contacts onto presumptive projection (relay) neuron dendrites. The somata of these interneurons were small (mean = 178 μm2), but the dendritic trees were large compared with those of projection neurons. All three interneurons had similar synaptic patterns onto their dendrites with about equal numbers of retinal, cortical, and GABAergic contacts. The distribution of these contacts was more uniform compared with the same types of contacts made onto projection neurons. The presynaptic dendrites were observed to contact only the dendrites of presumptive projection neurons, and these contacts were nearly all in the form of geniculate triads. None of the three interneurons displayed an axon. The receptive fields of these interneurons were similar to those of projection cells, but were larger and had center-response signs that were the opposite of the projection neurons around them (e.g. OFF center for the dorsal part of the parvocellular mass where ON-center projection neurons reside). The squirrel monkey data provides additional evidence that one aspect of the laminar pattern observed in the parvocellular pathway of the primate's dLGN might be related to a segregation of projection neurons of one center-response sign with interneurons of the opposite center-response sign.

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