Showing papers on "Receptive field published in 1967"

The laminar organization of dorsal horn and effects of descending impulses.

Abstract: 1. An examination of the physiological properties of cells in cat lumbar dorsal horn shows that there are three horizontal laminae which correspond approximately to Rexed (1952) laminae 4, 5, and 6.2. A summary diagram (Fig. 9) suggests the relation of the laminae to each other and to afferent and descending fibres. All three laminae respond to cutaneous stimulation but only lamina 6 responds to movement. By comparing responses of cells in decerebrate and spinal preparations, it is shown that the brain stem inhibits cutaneous responses and enhances movement responses. Pyramidal tract stimulation affects cells in laminae 4, 5, and 6.3. Cells in lamina 4 have small cutaneous receptive fields and respond as though many different types of specific cutaneous afferents converge on them. Cells in lamina 5 respond as though many cells of lamina 4 converge on them. In the decerebrate animal the responses of lamina 5 cells habituate to repeated light pressure stimuli but the cells remain responsive to new stimuli in other parts of their receptive field. Impulses descending from the brain stem can switch the modality of lamina 6 cells from cutaneous to proprioceptive.

Receptive fields and trigger features of ganglion cells in the visual streak of the rabbit's retina

Abstract: 1. A survey of the properties of retinal ganglion cells in the central part of the rabbit retina has been carried out. 2. The five types of unit previously encountered in the peripheral retina were also found in the central region. Their receptive fields were smaller, and tended to be oval-shaped with the long axis horizontal. 3. In addition, three new types were discovered: orientation-selective cells, local-edge-detectors, uniformity-detectors. 4. Orientation-selective cells were sensitive to either vertically or horizontally extended targets. Analysis suggested they were modified concentric units with an incomplete antagonistic surround. 5. Local-edge-detectors responded to the appearance or movement of a contrasting border within the receptive field. They were inhibited by similar stimulation of the region surrounding the receptive field. Detailed attention was given to the demonstration of edge-detection. 6. Uniformity detectors had a relatively high level of ongoing activity in the absence of stimulation. All forms of stimulation (lights flashed on or off, movement of darker or lighter targets) produced a diminution or cessation of ongoing activity. 7. The results are compared with behaviour described in other species.

Goldfish Retina: Organization for Simultaneous Color Contrast

Abstract: The majority of ganglion cells in the retina of goldfish have receptive fields organized so that the cells respond particularly to simultaneous contrasts of color. The receptive fields are concentrically arranged. If the cell is excited by red light in the center, then it will also be excited by green light in the periphery, and inhibited by green light in the center or red light in the periphery. The occurrence of this arrangement and the reverse is about equal. The receptive field is much larger than had previously been thought.

The effects of light-adaptation on rod and cone receptive field organization of monkey ganglion cells

Abstract: 1. Receptive fields of perifoveal ganglion cells have been measured by determining threshold for eliciting a just detectable response using either concentric spot stimuli centred on the receptive field or small spot stimuli in different parts of the receptive field at various states of retinal adaptation and with stimuli selected to separate rod from cone function. 2. Light-adaptation decreases the sensitivity, latency and duration of threshold responses throughout the receptive field of a ganglion cell. 3. With all patterns of retinal stimulation and states of adaptation, threshold signals of the rods reach a ganglion cell later and those of the cones earlier than approximately 50 msec after a light stimulus. 4. In the more dark-adapted retina threshold rod and cone signals can be transmitted to the brain by the same or by neighbouring ganglion cells but not simultaneously; in the light-adapted state only the cone signal is transmitted.

Receptive Fields in the Cat Retina: A New Type

Abstract: A new type of receptive field of cat retinal ganglion cells is described and termed the "suppressed-by-contrast" type. The firing rate of these cells is suppressed by a variety of visual stimuli. However, it has not been possible to find a stimulus that increases the firing rate above the maintained level.

A quantitative analysis of movement detecting neurons in the frog's retina

Abstract: In the frog's retina (Rana esculenta, Rana pipiens) two classes of neurons which are especially sensitive to stimuli moved through the receptive fields were investigated. It was found that the following stimulus parameters determine the response of these class-2 and class-3 neurons: angular velocity (v), stimulus size (A), contrast of stimulus against a white or a black background (c), position of the path of traverse in the receptive field (P), and the time (t) between the movement of identical stimuli along the same path through the receptive field. These parameters were changed within a considerable range; the relation between the parameter change and the neuronal response is given in different equations. A final formula, which allows one to calculate the average response of a class-2 or a class-3 neurons to a stimulus moved through the excitatory receptive field is given in equations 6a and 6b.

Ganglion cells in the frog retina: inhibitory receptive field and long-latency response.

Abstract: THE ganglion cells of the frog retina can be sub-divided into different functional classes1. When investigated under light adapted conditions, class I cells (sustained edge detectors) respond to sharp edges moving through their receptive field, giving a stronger response when the object causing the edge is small than when it is large. A sustained response occurs when an edge is stopped within the field. In darkness, with a standing edge present in the receptive field, a response can be elicited by turning on the light or by a short flash of light.

Cutaneous receptive fields of single nerve cells in the thalamus of the cat.

Abstract: This article describes some new receptive properties of cells in the nucleus ventralis posterolateralis It is shown that the nucleus contains mechanoceptive cells with excitatory or inhibitory thermoceptive influences on them, that the observation of surround inhibition in this nucleus depends in part on the type of anaesthesia used, and that some of the cells have directional sensitivity

Rabbit Visual Cortex: Reaction of Cells to Movement and Contrast

Abstract: IT has been shown that, in the rabbit, retinal ganglion cells1, geniculate cells2,3 and midbrain cells4 respond most readily to special aspects of light stimulation related to movement. In the cat5–7, by contrast, these peripheral systems respond most effectively to an alteration of intensity of a stationary light spot, and have their receptive fields concentrically arranged with “on-centres and off-surrounds” (or vice versa). In the rabbit, on the other hand, the shape and organization of peripheral receptive fields are less stereotyped.