scholarly journals Weak orientation and direction selectivity in lateral geniculate nucleus representing central vision in the gray squirrelSciurus carolinensis

2015 ◽  
Vol 113 (7) ◽  
pp. 2987-2997 ◽  
Author(s):  
Julia B. Zaltsman ◽  
J. Alexander Heimel ◽  
Stephen D. Van Hooser
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Visual Fields ◽  
Direction Selectivity ◽  
Orientation Selectivity ◽  
Substantial Contribution ◽  
Small Contribution ◽  
Central Vision ◽  
V1 Neurons ◽  
Lateral Geniculate ◽  
Strong Orientation

Classic studies of lateral geniculate nucleus (LGN) and visual cortex (V1) in carnivores and primates have found that a majority of neurons in LGN exhibit a center-surround organization, while V1 neurons exhibit strong orientation selectivity and, in many species, direction selectivity. Recent work in the mouse and the monkey has discovered previously unknown classes of orientation- and direction-selective neurons in LGN. Furthermore, some recent studies in the mouse report that many LGN cells exhibit pronounced orientation biases that are of comparable strength to the subthreshold inputs to V1 neurons. These results raise the possibility that, in rodents, orientation biases of individual LGN cells make a substantial contribution to cortical orientation selectivity. Alternatively, the size and contribution of orientation- or direction-selective channels from LGN to V1 may vary across mammals. To address this question, we examined orientation and direction selectivity in LGN and V1 neurons of a highly visual diurnal rodent: the gray squirrel. In the representation of central vision, only a few LGN neurons exhibited strong orientation or direction selectivity. Across the population, LGN neurons showed weak orientation biases and were much less selective for orientation compared with V1 neurons. Although direction selectivity was weak overall, LGN layers 3abc, which contain neurons that express calbindin, exhibited elevated direction selectivity index values compared with LGN layers 1 and 2. These results suggest that, for central visual fields, the contribution of orientation- and direction-selective channels from the LGN to V1 is small in the squirrel. As in other mammals, this small contribution is elevated in the calbindin-positive layers of the LGN

Activity of cells in area 17 of the cat in absence of input from layer a of lateral geniculate nucleus

1983 ◽  
Vol 49 (3) ◽  
pp. 595-610 ◽  
Author(s):  
J. G. Malpeli
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Striate Cortex ◽  
Receptive Fields ◽  
Direction Selectivity ◽  
Orientation Selectivity ◽  
Complex Cells ◽  
Normal Orientation ◽  
Lateral Geniculate ◽  
Special Complex ◽  
Cat Striate Cortex

1. Injections of 4 mM cobaltous chloride were used to block synaptic transmission in layer A of the lateral geniculate nucleus (LGN) without blocking fibers of passage going to or arising from other layers. 2. Selective inactivation of geniculate layer A virtually abolished all visual activity in cortical layers 4ab, 4c, and 6. Under these conditions, the stimulus-evoked response, orientation selectivity, and direction selectivity of cells in layers 2 and 3 were not seriously affected. In layer 5, the effects of the block were more variable, with special complex cells least affected and simple cells most affected. 3. Since the organization of complex receptive fields and the maintenance of normal orientation selectivity in supragranular layers survive disruption of major interlaminar interactions, it appears that much of the functional architecture of cat striate cortex does not depend on the integrity of the column. 4. These results support the idea that each layer of the LGN is a functional unit with a unique pattern of access to the various layers of visual cortex.

Lagged cells in alert monkey lateral geniculate nucleus

2008 ◽  
Vol 25 (5-6) ◽  
pp. 647-659 ◽  
Author(s):  
ALAN B. SAUL
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Extracellular Recording ◽  
Macaque Monkey ◽  
Direction Selectivity ◽  
Alert Monkey ◽  
Lateral Geniculate ◽  
Multiple Dimensions ◽  
Wide Range ◽  
Lagged Cells ◽  
Response Timing

AbstractFive lagged cells were recognized by extracellular recording in the lateral geniculate nucleus of an awake, behaving macaque monkey. Previous reports of lagged cells were all in the anesthetized cat. Both parvocellular and magnocellular lagged cells were observed. Response timing was distributed continuously across the population, and both sustained and transient responses were seen in the magnocellular subpopulation. Cortex thus receives signals with a wide range of timing, which can mediate direction selectivity across multiple dimensions.

Changes in visual fields and lateral geniculate nucleus in monkey laser-induced high intraocular pressure model

2008 ◽  
Vol 86 (5) ◽  
pp. 770-782 ◽  
Author(s):  
Masaaki Sasaoka ◽  
Katsuki Nakamura ◽  
Masamitsu Shimazawa ◽  
Yasushi Ito ◽  
Makoto Araie ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Lateral Geniculate Nucleus ◽  
Visual Fields ◽  
Lateral Geniculate

Direction and orientation selectivity of neurons in visual area MT of the macaque

1984 ◽  
Vol 52 (6) ◽  
pp. 1106-1130 ◽  
Author(s):  
T. D. Albright
Keyword(s):  
Direction Selectivity ◽  
Orientation Selectivity ◽  
Orientation Tuning ◽  
Area Mt ◽  
Mt Neurons ◽  
V1 Neurons ◽  
Moving Stimuli ◽  
Preferred Direction ◽  
Visual Area Mt ◽  
Direction Tuning

We recorded from single neurons in the middle temporal visual area (MT) of the macaque monkey and studied their direction and orientation selectivity. We also recorded from single striate cortex (V1) neurons in order to make direct comparisons with our observations in area MT. All animals were immobilized and anesthetized with nitrous oxide. Direction selectivity of 110 MT neurons was studied with three types of moving stimuli: slits, single spots, and random-dot fields. All of the MT neurons were found to be directionally selective using one or more of these stimuli. MT neurons exhibited a broad range of direction-tuning bandwidths to all stimuli (minimum = 32 degrees, maximum = 186 degrees, mean = 95 degrees). On average, responses were strongly unidirectional and of similar magnitude for all three stimulus types. Orientation selectivity of 89 MT neurons was studied with stationary flashed slits. Eighty-three percent were found to be orientation selective. Overall, orientation-tuning bandwidths were significantly narrower (mean = 64 degrees) than direction-tuning bandwidths for moving stimuli. Moreover, responses to stationary-oriented stimuli were generally smaller than those to moving stimuli. Direction selectivity of 55 V1 neurons was studied with moving slits; orientation selectivity of 52 V1 neurons was studied with stationary flashed slits. In V1, compared with MT, direction-tuning bandwidths were narrower (mean = 68 degrees). Moreover, V1 responses to moving stimuli were weaker, and bidirectional tuning was more common. The mean orientation-tuning bandwidth in V1 was also significantly narrower than that in MT (mean = 52 degrees), but the responses to stationary-oriented stimuli were of similar magnitude in the two areas. We examined the relationship between optimal direction and optimal orientation for MT neurons and found that 61% had an orientation preference nearly perpendicular to the preferred direction of motion, as is the case for all V1 neurons. However, another 29% of MT neurons had an orientation preference roughly parallel to the preferred direction. These observations, when considered together with recent reports claiming sensitivity of some MT neurons to moving visual patterns (39), suggest specific neural mechanisms underlying pattern-motion sensitivity in area MT. These results support the notion that area MT represents a further specialization over area V1 for stimulus motion processing. Furthermore, the marked similarities between direction and orientation tuning in area MT in macaque and owl monkey support the suggestion that these areas are homologues.

Functional Organization of Owl Monkey Lateral Geniculate Nucleus and Visual Cortex

1998 ◽  
Vol 80 (2) ◽  
pp. 594-609 ◽  
Author(s):  
Lawrence P. O'Keefe ◽  
Jonathan B. Levitt ◽  
Daniel C. Kiper ◽  
Robert M. Shapley ◽  
J. Anthony Movshon
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Lateral Geniculate Nucleus ◽  
Functional Organization ◽  
Frequency Tuning ◽  
V1 Neurons ◽  
Lateral Geniculate ◽  
Receptive Field Properties ◽  
Owl Monkey ◽  
P Cells

O'Keefe, Lawrence P., Jonathan B. Levitt, Daniel C. Kiper, Robert M. Shapley, and J. Anthony Movshon. Functional organization of owl monkey lateral geniculate nucleus and visual cortex. J. Neurophysiol. 80: 594–609, 1998. The nocturnal, New World owl monkey ( Aotus trivirgatus) has a rod-dominated retina containing only a single cone type, supporting only the most rudimentary color vision. However, it does have well-developed magnocellular (M) and parvocellular (P) retinostriate pathways and striate cortical architecture [as defined by the pattern of staining for the activity-dependent marker cytochrome oxidase (CO)] similar to that seen in diurnal primates. We recorded from single neurons in anesthetized, paralyzed owl monkeys using drifting, luminance-modulated sinusoidal gratings, comparing receptive field properties of M and P neurons in the lateral geniculate nucleus and in V1 neurons assigned to CO “blob,” “edge,” and “interblob” regions and across layers. Tested with achromatic stimuli, the receptive field properties of M and P neurons resembled those reported for other primates. The contrast sensitivity of P cells in the owl monkey was similar to that of P cells in the macaque, but the contrast sensitivities of M cells in the owl monkey were markedly lower than those in the macaque. We found no differences in eye dominance, orientation, or spatial frequency tuning, temporal frequency tuning, or contrast response for V1 neurons assigned to different CO compartments; we did find fewer direction-selective cells in blobs than in other compartments. We noticed laminar differences in some receptive field properties. Cells in the supragranular layers preferred higher spatial and lower temporal frequencies and had lower contrast sensitivity than did cells in the granular and infragranular layers. Our data suggest that the receptive field properties across functional compartments in V1 are quite homogeneous, inconsistent with the notion that CO blobs anatomically segregate signals from different functional “streams.”

Neurotransmitter receptors mediating excitatory input to cells in the cat lateral geniculate nucleus. II. Nonlagged cells

1990 ◽  
Vol 63 (6) ◽  
pp. 1361-1372 ◽  
Author(s):  
E. Hartveit ◽  
P. Heggelund
Keyword(s):  
Nmda Receptors ◽  
Lateral Geniculate Nucleus ◽  
Excitatory Input ◽  
Average Degree ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Small Contribution ◽  
Nmda Antagonists ◽  
Response Component ◽  
Lateral Geniculate

1. We studied the type of receptor for excitatory amino acids (EAA) that mediates visual responses of nonlagged cells in the dorsal lateral geniculate nucleus (LGN) by recording the visual response of single cells to a stationary flashing spot before, during, and after iontophoretical application of antagonists and agonists to EAA receptors. 2. The visual response of the nonlagged cells was strongly suppressed, in a dose-dependent manner, by the specific quisqualate/kainate receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX). The average degree of suppression was 74%. Quisqualate enhanced the visual response. 3. Specific antagonists to the N-methyl-D-aspartate (NMDA) receptor had a weak suppressing effect on most nonlagged cells. The average degree of suppression was 22%. Measurement of such weak effects was complicated by the considerable spontaneous fluctuations of responsivity in the LGN cells. In the majority of cells where the visual response was suppressed by NMDA antagonists, the tonic response component was more strongly suppressed than the initial transient response component. The visual response was enhanced by NMDA, and this enhancement was antagonized by NMDA antagonists. 4. These findings suggest that the excitatory input from the retina to nonlagged LGN cells is mainly mediated by non-NMDA receptors. The non-NMDA receptors mediate fast EPSPs, and this can explain the fast onset and offset of the visual response of the nonlagged cells. 5. The generally small contribution from NMDA receptors to the visual response of the nonlagged cells might reflect a minor involvement of these receptors in the retinal input, or it could be related to the excitatory input to LGN from the visual cortex. 6. To study whether the expression of NMDA receptors was related to modulatory brain stem input to LGN, we examined the effects of the NMDA antagonists when the visual response was enhanced with gamma-aminobutyric acid (GABA) antagonists or acetylcholine (ACh). Neither of these pharmacologic manipulations consistently increased the relative contribution of NMDA receptors to the visual response. 7. No pharmacologic difference was found between nonlagged X- and Y-cells, or between ON- and OFF-center cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Velocity sensitivity and direction selectivity of neurons in areas V1 and V2 of the monkey: influence of eccentricity

1986 ◽  
Vol 56 (2) ◽  
pp. 462-480 ◽  
Author(s):  
G. A. Orban ◽  
H. Kennedy ◽  
J. Bullier
Keyword(s):  
Receptive Field ◽  
Broad Band ◽  
Receptive Fields ◽  
Direction Selectivity ◽  
Central Vision ◽  
Response Curves ◽  
Stimulus Velocity ◽  
V1 Neurons ◽  
Velocity Sensitivity ◽  
Low Pass

One hundred and forty two neurons in V1 and V2 were quantitatively tested using a multihistogram technique in paralyzed and anesthetized macaque monkeys. V1 neurons with receptive fields within 2 degrees from the fixation point (central V1 sample) and V1 neurons with eccentric receptive fields (15-25 degrees eccentricity, peripheral V1 sample) were compared to assess changes in velocity sensitivity and direction selectivity with eccentricity. The central V1 sample was compared with V2 neurons with receptive fields in the same part of the visual field (central V2 sample) to compare the involvement of both areas in the analysis of motion. Velocity sensitivity of V1 neurons shifts to faster velocities with increasing eccentricity. V1 and V2 neurons subserving central vision have similar preference for slow movements. All neurons could be classified into three categories according to their velocity-response curves: velocity low pass, velocity broad band, and velocity tuned. Most cells in parts of V1 and V2 subserving central vision are velocity low pass. As eccentricity increases in V1, velocity low-pass cells give way to velocity broad-band cells. There is a significant correlation between velocity upper cutoff and receptive field width among V1 neurons. The change in upper cutoff velocity with eccentricity depends both on temporal and spatial factors. Direction selectivity depends on stimulus velocity in most V1 cells. Neurons in the central V1 sample retain their direction selectivity at lower speeds than do neurons in the peripheral V1 sample. The proportion of direction-selective cells is low in both V1 and V2. In V1, direction selectivity decreases with eccentricity. In V1, both velocity upper cutoff and direction selectivity correlate more with laminar position than with receptive field type. The similarity between V1 of the monkey and area 17 of the cat, and the dissimilarity between V2 of the monkey and area 18 of the cat, are discussed.

Neuronal responses to edges defined by luminance vs. temporal texture in macaque area V1

1997 ◽  
Vol 14 (5) ◽  
pp. 949-962 ◽  
Author(s):  
Avi Chaudhuri ◽  
Thomas D. Albright
Keyword(s):  
Luminance Contrast ◽  
Direction Selectivity ◽  
Image Features ◽  
Orientation Selectivity ◽  
Close Correspondence ◽  
Neuronal Responses ◽  
V1 Neurons ◽  
Texture Contrast ◽  
Direction Tuning ◽  
Made In

AbstractWe examined the responsivity, orientation selectivity, and direction selectivity of a sample of neurons in cortical area V1 of the macaque using visual stimuli consisting of drifting oriented contours defined by each of two very different figural cues: luminance contrast and temporal texture. Comparisons of orientation and direction tuning elicited by the different cues were made in order to test the hypothesis that the neuronal representations of these parameters are form-cue invariant. The majority of the sampled cells responded to both stimulus types, although responses to temporal texture stimuli were generally weaker than those elicited by luminance-defined stimuli. Of those units exhibiting orientation selectivity when tested with the luminance-defined stimuli, more than half were also selective for the orientation of the temporal texture stimuli. There was close correspondence between the preferred orientations and tuning bandwidths revealed with the two stimulus types. Of those units exhibiting directional selectivity when tested with the luminance-defined stimuli, about two-thirds were also selective for the direction of the temporal texture stimuli. There was close correspondence between the preferred directions revealed with the two stimulus types, although bidirectional responses were somewhat more common when temporal texture stimuli were used. These results indicate that many V1 neurons encode orientation and direction of motion of retinal image features in a manner that is largely independent of whether the feature is defined by luminance or temporal texture contrast. These neurons may contribute to perceptual phenomena in which figural cue identity is disregarded.

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