scholarly journals Contribution of the cortico-claustral loop to receptive field properties in area 17 of the cat

1983 ◽  
Vol 3 (11) ◽  
pp. 2121-2127 ◽  
Author(s):  
H Sherk ◽  
S LeVay
Keyword(s):  
Receptive Field ◽  
Area 17 ◽  
Receptive Field Properties

Cat area 17. I. Pattern of thalamic control of cortical layers

1986 ◽  
Vol 56 (4) ◽  
pp. 1062-1073 ◽  
Author(s):  
J. G. Malpeli ◽  
C. Lee ◽  
H. D. Schwark ◽  
T. G. Weyand
Keyword(s):  
Receptive Field ◽  
Direction Selectivity ◽  
Orientation Selectivity ◽  
The Other ◽  
Area 17 ◽  
Cortical Layers ◽  
Reversible Inactivation ◽  
Receptive Field Properties ◽  
Contralateral Eye ◽  
Necessary And Sufficient

Reversible inactivation of individual layers of the cat lateral geniculate and medial interlaminar nuclei was used to investigate the necessary and sufficient inputs for maintaining visually driven activity and receptive field properties in area 17. Neither orientation selectivity nor direction selectivity depends on any individual geniculate layer. We identified two groups of cortical layers on the basis of the pattern of thalamic inputs providing visual driving through the contralateral eye. One group, consisting of layers 4 and 6, has geniculate layer A as its only necessary and sufficient input. The other, consisting of supragranular layers, integrates at least two sufficient thalamic inputs, one of which is layer A. Several major receptive field properties are independently generated in these two groups of layers.

Visual responsiveness and direction selectivity of cells in area 18 during local reversible inactivation of area 17 in cats

1992 ◽  
Vol 9 (6) ◽  
pp. 581-593 ◽  
Author(s):  
C. Casanova ◽  
Y. Michaud ◽  
C. Morin ◽  
P.A. McKinley ◽  
S. Molotchnikoff
Keyword(s):  
Receptive Field ◽  
Specific Effect ◽  
Direction Selectivity ◽  
Area 17 ◽  
Visual Responses ◽  
Drug Injection ◽  
Area 18 ◽  
Preferred Direction ◽  
Receptive Field Properties ◽  
Number Of Cells

AbstractWe have investigated the effects of inactivation of localized sites in area 17 on the visual responses of cells in visuotopically corresponding regions of area 18. Experiments were performed on adult normal cats. The striate cortex was inactivated by the injection of nanoliters of lidocaine hydrochloride or of γ-aminobutyric acid (GABA) dissolved in a staining solution. Responses of the simple and complex cells of area 18 to optimally oriented light and dark bars moving in the two directions of motion were recorded before, during, and after the drug injection. Two main effects are described.First, for a substantial number of cells, the drug injection provoked an overall reduction of the cell's visual responses. This nonspecific effect largely predominated in the complex cell family (76% of the units affected). This effect is consistent with the presence of long-range excitatory connections in the visual cortex.Second, the inactivation of area 17 could affect specific receptive-field properties of cells in area 18. The main specific effect was a loss of direction selectivity of a number of cells in area 18, mainly in the simple family (more than 53% of the units affected). The change in direction selectivity comes either from a disinhibitory effect in the nonpreferred direction or from a reduction of response in the preferred direction. It is proposed that the disinhibitory effects were mediated by inhibitory interneurones within area 18. In a very few cases, the change of directional preference was associated with a modification of the cell's response profile.These results showed that the signals from area 17 are necessary to drive a number of units in area 18, and that area 17 can contribute to, or at least modulate, the receptive-field properties of a large number of cells in the parastriate area.

Two visual corticotectal systems in cat

1984 ◽  
Vol 52 (6) ◽  
pp. 1226-1245 ◽  
Author(s):  
K. Ogasawara ◽  
J. G. McHaffie ◽  
B. E. Stein
Keyword(s):  
Receptive Field ◽  
Spatial Summation ◽  
Small Population ◽  
General Level ◽  
Target Cells ◽  
Area 17 ◽  
Functional Roles ◽  
Receptive Field Properties ◽  
Cortical Cooling ◽  
Superficial Lamina

By using the method of cortical cooling we were able to deactivate specific regions of cortex and demonstrate that there are two functionally separate visual projections to the superior colliculus (SC): one from area 17-18 and one from posterior regions of the suprasylvian cortex (PSSC). Deactivation of area 17-18 depressed the activity of nearly all of the superficial lamina cells in the SC that were binocular and directionally selective. The receptive-field properties of those cells still capable of responding to visual stimuli were altered significantly so that 1) moving stimuli became poorly effective, while stationary flashed stimuli became relatively more effective; 2) directional selectivity and binocularity were minimized or eliminated; 3) the characteristic spatial summation, inhibition, and suppressive surround of the SC-receptive field were compromised; and 4) the range of effective stimulus velocities was altered. However, deep lamina cells were unaffected by the cooling of area 17-18. Deactivation of the PSSC affected deep lamina SC cells in the same way that the cooling of area 17-18 affected cells in superficial layers. Apparently there are two functional visual corticotectal systems that are largely independent of each other: one from area 17-18 (to superficial SC cells) and one from the PSSC (to deep SC cells). Both are critically important for maintaining the excitability and complex receptive-field properties of their target cells in the SC. The only exception to the complete segregation of their influences was the ability of the PSSC to affect slightly the general level of excitability of some superficial lamina cells. A small population of SC cells receiving a tonic inhibitory corticotectal influence was also located. This influence was apparent as an increase in excitability and receptive-field complexity of cells in superficial layers when area 17-18 was cooled, and of deep lamina cells when the PSSC was cooled. The presence of separate visual corticotectal influences on superficial and deep lamina SC cells is consistent with the distinct identities of these subdivisions of the SC and their different functional roles.

Visual receptive-field properties of cells in area 18 of cat's cerebral cortex before and after acute lesions in area 17

1975 ◽  
Vol 38 (4) ◽  
pp. 735-750 ◽  
Author(s):  
B. Dreher ◽  
L. J. Cottee
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Visual Information ◽  
Receptive Fields ◽  
Area 17 ◽  
Moving Targets ◽  
Area 18 ◽  
Receptive Field Properties ◽  
Before And After ◽  
Bilateral Lesions

1. Receptive-field properties of single neurons in cat's cortical area 18 were studied before and after partial bilateral lesions of area 17. 2. The majority of cells recorded from animals with intact visual cortex exhibited orientation selectivity, directional selectivity, and could be independently activated through either eye. All cells responded well to moving targets and nearly all of them exhibited broadly tuned preferences with respect to speed of the target. Over 45% of cells responded optimally or exclusively at very fast (above 50 degrees/s) speeds. 3. The majority of neurons recorded from animals with intact visual cortex responded weakly but clearly to appropriately oriented localized stationary stimuli flashed on and off. About one-third of the cells responded with mixed on-off discharges from all over their receptive field. In the receptive fields of 10% of cells, separate on- and off-discharge regions could be revealed. In the receptive fields of the remaining cells, only on- or only off-discharge regions could be revealed. 4. The majority of neurons recorded after ablation of area 17 were orientation selective; 50% of the cells were also direction selective. All neurons responded well to moving targets; about 65% of them responded optimally or exclusively at very fast target speeds. 5. Destruction of the dorsolateral part of contralaterial area 17 and most of contralateral area 18 caused significant reduction in proportion of cells in area 18 which could be activated through either eye. 6. The majority of neurons recorded after ablation responded to appropriately oriented localized stationary stimuli flashed on and off. Cells with mixed on-off discharge regions all over the receptive field with separate on- and off-discharge regions and with only on- or only off-discharge regions were found. 7. It is concluded that the processing of afferent visual information in area 18 is, to a great extent, independent of the information carried to this area by associational fibers from cells of area 17.

Effects of selective pressure block of Y-type optic nerve fibers on the receptive-field properties of neurons in the striate cortex of the cat

1992 ◽  
Vol 9 (1) ◽  
pp. 47-64 ◽  
Author(s):  
W. Burke ◽  
B. Dreher ◽  
A. Michalski ◽  
B. G. Cleland ◽  
M. H. Rowe
Keyword(s):  
Optic Nerve ◽  
Receptive Field ◽  
Striate Cortex ◽  
Direction Selectivity ◽  
Nerve Fibers ◽  
Orientation Tuning ◽  
Area 17 ◽  
Single Neurons ◽  
Receptive Field Properties ◽  
Velocity Sensitivity

AbstractIn an aseptic operation under surgical anesthesia, one optic nerve of a cat was exposed and subjected to pressure by means of a special cuff. The conduction of impulses through the pressurized region was monitored by means of electrodes which remained in the animal after the operation. The pressure was adjusted to selectively eliminate conduction in the largest fibers (Y-type) but not in the medium-size fibers (X-type). The conduction block is probably due to a demyelination and remains complete for about 3 weeks. Within 2 weeks after the pressure-block operation, recordings were made from single neurons in the striate cortex (area 17, area VI) of the cat anesthetized with N2O/O2 mixture supplemented by continuous intravenous infusion of barbiturate. Neurons were activated visually via the normal eye and via the eye with the pressure-blocked optic nerve (“Y-blocked eye”). Several properties of the receptive fields of single neurons in area 17 such as S (simple) or C (complex) type of receptive-field organization, size of discharge fields, orientation tuning, direction-selectivity indices, and end-zone inhibition appear to be unaffected by removal of the Y-type input. On the other hand, the peak discharge rates to stimuli presented via the Y-blocked eye were significantly lower than those to stimuli presented via the normal eye. As a result, the eye-dominance histogram was shifted markedly towards the normal eye implying that there is a significant excitatory Y-type input to area 17. In a substantial proportion of area 17 neurons, this input converges onto the cells which receive also non-Y-type inputs. In one respect, velocity sensitivity, removal of the Y input had a weak but significant effect. In particular, C (but not S) cells when activated via the normal eye responded optimally at slightly higher stimulus velocities than when activated via the Y-blocked eye. These results suggest that the Y input makes a distinct contribution to velocity sensitivity in area 17 but only in C-type neurons. Overall, our results lead us to the conclusion that the Y-type input to the striate cortex of the cat makes a significant contribution to the strength of the excitatory response of many neurons in this area. However, the contributions of Y-type input to the mechanism(s) underlying many of the receptive-field properties of neurons in this area are not distinguishable from those of the non-Y-type visual inputs.

Depth perception and cortical physiology in normal and innate microstrabismic cats

1991 ◽  
Vol 6 (1) ◽  
pp. 25-41 ◽  
Author(s):  
C. Distler ◽  
K.-P. Hoffmann
Keyword(s):  
Receptive Field ◽  
Depth Perception ◽  
Cortical Neurons ◽  
Oblique Effect ◽  
Orientation Tuning ◽  
Maximal Response ◽  
Horizontal Distance ◽  
Area 17 ◽  
Receptive Field Properties ◽  
Stimulation Of

AbstractEvidence is presented that innate microstrabismus and abnormal cortical visual receptive-field properties can occur also in cats without any apparent involvement of the Siamese or albino genetic abnormalities in their visual system. A possible cause for microstrabismus in these cats may be sought in an abnormally large horizontal distance between blind spot and area centralis indicated by a temporal displacement of the most central receptive fields on both retinae.Depth perception was found to be impaired in cats with innate microstrabismus. Behavioral measurements using a Y-maze revealed in four such cats that the performance in recognizing the nearer of two random-dot patterns did not improve when they were allowed to use both eyes instead of only one. The ability of microstrabismic cats to perceive depth under binocular viewing conditions only corresponded to the monocular performance of five normal cats.Electrophysiological recordings were performed in the visual cortex (areas 17 and 18) of four awake cats, two normal, and two innate microstrabismic animals. Ocular dominance and orientation tuning of single neurons in area 17 and 18 were analyzed quantitatively.The percentage of neurons in area 17 and 18 which could be activated through either eye was significantly reduced to 49.7% in the microstrabismic animals when compared to the normal cats (74.8%). “True binocular cells,” which can only be activated by simultaneous stimulation of both eyes, were significantly less frequent (1.6%) in microstrabismic cats than in normal animals (10.4%). However, subthreshold binocular interactions were identical in both groups of animals. In the strabismic animals, long-term binocular stimulation of monocular neurons did not give a clear indication of alternating use of one or the other eye.The range of stimulus orientations leading to discharge rates above 50% of the maximal response, i.e. the half-width of the orientation tuning curves, was the same in the two groups of cats. However, orientation sensitivity, i.e. the alternation in discharge rate per degree change in stimulus orientation, was higher in cortical cells of normal cats than in those of microstrabismic cats.In normal and microstrabismic cats, no clear sign of an “oblique effect,” i.e. the preference of cortical neurons for vertical and horizontal orientations compared to oblique orientations, could be found neither in the incidence of cells with horizontal or vertical preferred orientation nor in the sharpness of orientation tuning and sensitivity of these neurons.In summary, the receptive-field properties reported here for awake innate microstrabismic cats are similar to those reported in the literature for anesthetized cats with varying degrees of albinism and for cats with artificial symmetrical strabismus surgically induced by sectioning the equivalent extraocular muscles in both eyes. Our innate microstrabismic cats may provide, however, an animal model for investigating the etiology of one form of naturally occurring strabismus.

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