Receptive Field Properties Of Neurons Research Articles

Effects of visual cortex removal on receptive-field properties of neurons in lateral suprasylvian visual area of the cat

Effects of visual cortex removal on receptive-field properties of neurons in lateral suprasylvian visual area of the cat

Receptive-field properties of neurons in different laminae of visual cortex of the cat.

1. Receptive-field properties of neurons in the different layers of the visual cortex of normal adult cats were analyzed quantitatively. Neurons were classified into one of two groups: 1) S-cells, which have discrete on- and/or off-regions in their receptive fields and possess inhibitory side bands; 2) C-cells, which do not have discrete on- and off-regions in their receptive fields but display an on-off response to flashing stimuli. Neurons of this type rarely display side-band inhibition. 2. As a group, S-cells display lower relative degrees of binocularity and are more selective for stimulus orientation than C-cells. In addition, within a given lamina the S-cells have smaller receptive fields, lower cutoff velocities, lower peak responses to visual stimulation, and lower spontaneous activity than do the C-cells. 3. S-cells in all layers of the cortex display similar orientation sensitivities, mean spontaneous discharge rates, peak response to visual stimulation, and degrees of binocularity. 4. Many of the receptive-field properties of cortical cells vary with laminar location. Receptive-field sizes and cutoff velocities of S-cells and of C-cells are greater in layers V and VI than in layers II-IV. For S-cells, preferred velocities are also greater in layers V and VI than in layers II-IV. Furthermore, C-cells in layers V and VI display high mean spontaneous discharge rates, weak orientation preferences, high relative degrees of binocularity, and higher peak responses to visual stimulation when compared to C-cells in layers II and III. 5. The receptive-field properties of cells in layers V-VI of the striate cortex suggest that most neurons that have their somata in these laminae receive afferents from LGNd Y-cells. Hence, our results suggest that afferents from LGNd Y-cells may play a major part in the cortical control of subcortical visual functions.

Neuronal receptive field properties in feline nucleus reticularis gigantocellularis

Nucleus reticularis gigantocellularis (NGC) has been shown, using both behavioral and physiological techniques, to be involved in the processing of nociceptive information. However, previous studies of the receptive fields of NGC neurons have utilized only innocuous stimuli. Thus, while neurons in NGC may play an important role in nociception, the receptive field properties of these cells remain to be defined. This investigation was designed to determine the receptive field properties of neurons in NGC using nociceptive and innocuous stimuli. Receptive fields were determined for 127 neurons in NGC. Eighty-seven percent of the NGC neurons studied responded exclusively to noxious stimuli, while 13% also responded to innocuous stimuli. None of the neurons studied responded exclusively to innocuous stimuli. The receptive fields of most NGC neurons (63%) were large, discontinuous, and bilaterally symmetrical. Eighty-one percent of NGC neurons received convergent inputs from both spinal and trigeminal systems. These receptive field properties differ from those previously reported using only innocuous stimulation

Receptive-field properties of neurons in binocular and monocular segments of striate cortex in cats raised with binocular lid suture.

1. We studied the receptive fields of 171 striate cortical neurons from 17 cats raised with binocular lid suture. Of these, 102 fields were within 10 degrees of the area centralis and the remaining 69 were at least 38 degrees from the vertical meridian. 2. Based on their different response properties, cells were divided into three broad groups: the mappable cells (49%) had clearly defined receptive fields, the unmappable cells (31%) were activated by visual stimuli but had diffuse fields which could not be hand plotted, and the visually inexcitable cells (20%) could not be activated by visual stimuli. Very few (less than or equal to 12% of the total sample) normal simple or complex cells could be found. 3. Orientation selectivity was assessed in these cells. Only 12% displayed orientation selectivity within normal bounds, and these were all mappable cells. None of the unmappable cells had discernible orientation selectivity. 4. Ocular dominance was assessed for 62 of the centrally located receptive fields. Among mappable cells, there was an abnormally low proportion of binocular fields, while no such abnormality was seen for unmappable cells. 5. For 47 of the neurons, average response histograms were compiled for moving stimuli of various parameters in an effort to evoke the maximum discharge or peak response. This peak response was normal for mappable cells but reduced for unmappable cells. 6. We devised a technique for studying potential inhibitory receptive-field zones in these neurons, validated the method in normal striate cortex, and used it to test 20 mappable cells in the lid-sutured cats. None showed the pattern of strong inhibitory side bands seen in normal simple cells, although six showed weak or abnormal inhibitory zones. Interestingly, six of the seven visually inexcitable cells tested by this method had purely inhibitory receptive fields. 7. The effects of binocular suture were essentially identical for the binocular and monocular segments since the cell types and their response properties did not differ between these two areas of cortex. Furthermore, the cortical monocular segments of these cats seemed qualitatively different from the deprived cortical monocular segment after monocular suture. This extends an analogous difference for these cats reported for the monocular segments of the lateral geniculate nucleus. We thus conclude that monocularly and binocularly sutured cats develop by qualitatively different mechanisms. For the former, competition between central synapses related to each eye is a prominent feature of geniculocortical development, whereas, for the latter, such specific forms of geniculocortical development may not obtain.

Orientation specificity of cells in cat striate cortex.

Orientation specificity of cells in cat striate cortex.

Projection of X- and Y-cells of the cat's lateral geniculate nucleus to areas 17 and 18 of visual cortex.

Projection of X- and Y-cells of the cat's lateral geniculate nucleus to areas 17 and 18 of visual cortex.

Visual receptive fields in the superior colliculus of the cat.

Visual receptive fields in the superior colliculus of the cat.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.