scholarly journals Brainstem modulation of visual response properties of single cells in the dorsal lateral geniculate nucleus of cat

2002 ◽  
Vol 543 (2) ◽  
pp. 541-554 ◽  
Author(s):  
I.T. Fjeld ◽  
O. Ruksenas ◽  
P. Heggelund
2005 ◽  
Vol 93 (6) ◽  
pp. 3224-3247 ◽  
Author(s):  
Matthew S. Grubb ◽  
Ian D. Thompson

Thalamic relay cells fire action potentials in two modes: burst and tonic. Previous studies in cats have shown that these two modes are associated with significant differences in the visual information carried by spikes in the dorsal lateral geniculate nucleus (dLGN). Here we describe the visual response properties of burst and tonic firing in the mouse dLGN. Extracellular recordings of activity in single geniculate cells were performed under halothane and nitrous oxide anesthesia in vivo. After confirming that the criteria used to isolate burst spikes from these recordings identify firing events with properties described for burst firing in other species and preparations, we show that burst firing in the mouse dLGN occurs during visual stimulation. We then compare burst and tonic firing across a wide range of visual response characteristics. While the two firing modes do not differ with respect to spatial summation or spatial frequency tuning, they show significant differences in the temporal domain. Burst spikes are phase advanced relative to their tonic counterparts. Burst firing is also more rectified, possesses sharper temporal frequency tuning, and prefers lower temporal frequencies than tonic firing. In addition, contrast-response curves are more step-like for burst responses. Finally, we present analyses that describe the stimulus detection abilities and spike timing reliability of burst and tonic firing.


1993 ◽  
Vol 10 (2) ◽  
pp. 325-339 ◽  
Author(s):  
E. Hartveit ◽  
P. Heggelund

AbstractThis study examined the influence of the pontomesencephalic peribrachial region (PBR) on the visual response properties of cells in the dorsal lateral geniculate nucleus (LGN). The response of single cells to a stationary flashing light spot was recorded with accompanying electrical stimulation of the PBR. The major objectives were to compare the effects of PBR stimulation on lagged and nonlagged cells, to examine how the visual response pattern of lagged cells could be modified by PBR stimulation and to examine whether the physiological criteria used to classify lagged and nonlagged cells are applicable during increased PBR input to the LGN. During PBR stimulation, the visual response was enhanced to a similar degree for lagged and nonlagged cells and the latency to half-rise of the visual response was reduced, particularly for the lagged X cells. The latency to half-fall of the visual response of lagged cells was not changed by PBR stimulation. Accordingly, the division of LGN cells into lagged and nonlagged cells based on visual response latencies was maintained during PBR stimulation. The initial suppression that a visual stimulus evokes in lagged cells was resistant to the effects of PBR stimulation. For the lagged cells, the largest response increase occurred for the initial part of the visual response. For the nonlagged cells, the largest increase occurred for the tonic part of the response. The results support the hypothesis that the differences in temporal response properties between lagged and nonlagged cells belong to the basic distinctions between these cell classes.


2003 ◽  
Vol 90 (6) ◽  
pp. 3594-3607 ◽  
Author(s):  
Matthew S. Grubb ◽  
Ian D. Thompson

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.


2007 ◽  
Vol 104 (18) ◽  
pp. 7670-7675 ◽  
Author(s):  
John S. Pezaris ◽  
R. Clay Reid

Electrical stimulation of the visual system might serve as the foundation for a prosthetic device for the blind. We examined whether microstimulation of the dorsal lateral geniculate nucleus of the thalamus can generate localized visual percepts in alert monkeys. To assess electrically generated percepts, an eye-movement task was used with targets presented on a computer screen (optically) or through microstimulation of the lateral geniculate nucleus (electrically). Saccades (fast, direct eye movements) made to electrical targets were comparable to saccades made to optical targets. Gaze locations for electrical targets were well predicted by measured visual response maps of cells at the electrode tips. With two electrodes, two distinct targets could be independently created. A sequential saccade task verified that electrical targets were processed not in motor coordinates, but in visual spatial coordinates. Microstimulation produced predictable visual percepts, showing that this technique may be useful for a visual prosthesis.


1983 ◽  
Vol 50 (1) ◽  
pp. 240-264 ◽  
Author(s):  
S. C. Mangel ◽  
J. R. Wilson ◽  
S. M. Sherman

We measured response properties of X- and Y-cells from laminae A and A1 of the dorsal lateral geniculate nucleus of monocularly lid-sutured cats at 8, 12, 16, 24, and 52-60 wk of age. Visual stimuli consisted of small spots of light and vertically oriented sine-wave gratings counterphased at a rate of 2 cycles/s. In cats as young as 8 wk of age, nondeprived and deprived neurons could be clearly identified as X-cells or Y-cells with criteria previously established for adult animals. Nonlinear responses of Y-cells from 8- and 12-wk-old cats were often temporally labile; that is, the amplitude of the nonlinear response of nondeprived and deprived cells increased or decreased suddenly. A similar lability was not noted for the linear response component. This phenomenon rarely occurred in older cats. At 8 wk of age, Y-cell proportions (number of Y-cells/total number of cells) in nondeprived and deprived A-laminae were approximately equal. By 12 wk of age and thereafter, the proportion of Y-cells in deprived laminae was significantly lower than that in nondeprived laminae. At no age was there a systematic difference in response properties (spatial resolution, latency to optic chiasm stimulation, etc.) for Y-cells between deprived and nondeprived laminae. Spatial resolution, defined as the highest spatial frequency to which a cell would respond at a contrast of 0.6, was similar for nondeprived and deprived X-cells until 24 wk of age. In these and older cats, the mean spatial resolution of deprived X-cells was lower than that of nondeprived X-cells. This difference was noted first for lamina A1 at 24 wk of age and later for lamina A at 52-60 wk of age. The average latency of X-cells to optic chiasm stimulation was slightly greater in deprived laminae than in nondeprived laminae. No such difference was seen for Y-cells. Cells with poor and inconsistent responses were encountered infrequently but were observed far more often in deprived laminae than in nondeprived laminae. Lid suture appears to affect the development of geniculate X- and Y-cells in very different ways. Not only is the final pattern of abnormalities quite different between these cell groups, but the developmental dynamics of these abnormalities also differ.


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