scholarly journals The influence of visual and auditory receptive field organization on multisensory integration in the superior colliculus

2002 ◽  
Vol 143 (3) ◽  
pp. 394-394 ◽  
Author(s):  
Daniel C. Kadunce ◽  
J. William Vaughan ◽  
Mark T. Wallace ◽  
Barry E. Stein
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Multisensory Integration ◽  
Field Organization ◽  
Receptive Field Organization

Comparison of the responses of AII amacrine cells in the dark- and light-adapted rabbit retina

1999 ◽  
Vol 16 (4) ◽  
pp. 653-665 ◽  
Author(s):  
DAIYAN XIN ◽  
STEWART A. BLOOMFIELD
Keyword(s):  
Receptive Field ◽  
Light Adaptation ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Rabbit Retina ◽  
Response Component ◽  
Synaptic Inputs ◽  
Field Organization ◽  
Receptive Field Organization ◽  
Aii Amacrine Cells

We studied the light-evoked responses of AII amacrine cells in the rabbit retina under dark- and light-adapted conditions. In contrast to the results of previous studies, we found that AII cells display robust responses to light over a 6–7 log unit intensity range, well beyond the operating range of rod photoreceptors. Under dark adaptation, AII cells showed an ON-center/OFF-surround receptive-field organization. The intensity–response profile of the center-mediated response component followed a dual-limbed sigmoidal function indicating a transition from rod to cone mediation as stimulus intensities were increased. Following light adaptation, the receptive-field organization of AII cells changed dramatically. Light-adapted AII cells showed both ON- and OFF-responses to stimulation of the center receptive field, but we found no evidence for an antagonistic surround. Interestingly, the OFF-center response appeared first following rapid light adaptation and was then replaced gradually over a 1–4 min period by the emerging ON-center response component. Application of the metabotropic glutamate receptor agonist APB, the ionotropic glutamate blocker CNQX, 8-bromo-cGMP, and the nitric oxide donor SNAP all showed differential effects on the various center-mediated responses displayed by dark- and light-adapted AII cells. Taken together, these pharmacological results indicated that different synaptic circuits are responsible for the generation of the different AII cell responses. Specifically, the rod-driven ON-center responses are apparently derived from rod bipolar cell synaptic inputs, whereas the cone-driven ON-center responses arise from signals crossing the gap junctions between AII cells and ON-center cone bipolar cells. Additionally, the OFF-center response of light-adapted AII cells reflects direct synaptic inputs from OFF-center cone bipolar cells to AII dendritic processes in the distal inner plexiform layer.

Two-dimensional receptive-field organization in striate cortical neurons of the cat

1994 ◽  
Vol 11 (4) ◽  
pp. 703-720 ◽  
Author(s):  
Ming Sun ◽  
A. B. Bonds
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Ocular Dominance ◽  
Receptive Fields ◽  
Field Size ◽  
Two Dimensional ◽  
Cortical Layers ◽  
Field Organization ◽  
Receptive Field Organization ◽  
Cortical Receptive Fields

AbstractThe two-dimensional organization of receptive fields (RFs) of 44 cells in the cat visual cortex and four cells from the cat LGN was measured by stimulation with either dots or bars of light. The light bars were presented in different positions and orientations centered on the RFs. The RFs found were arbitrarily divided into four general types: Punctate, resembling DOG filters (11%); those resembling Gabor filters (9%); elongate (36%); and multipeaked-type (44%). Elongate RFs, usually found in simple cells, could show more than one excitatory band or bifurcation of excitatory regions. Although regions inhibitory to a given stimulus transition (e.g. ON) often coincided with regions excitatory to the opposite transition (e.g. OFF), this was by no means the rule. Measurements were highly repeatable and stable over periods of at least 1 h. A comparison between measurements made with dots and with bars showed reasonable matches in about 40% of the cases. In general, bar-based measurements revealed larger RFs with more structure, especially with respect to inhibitory regions. Inactivation of lower cortical layers (V-VI) by local GABA injection was found to reduce sharpness of detail and to increase both receptive-field size and noise in upper layer cells, suggesting vertically organized RF mechanisms. Across the population, some cells bore close resemblance to theoretically proposed filters, while others had a complexity that was clearly not generalizable, to the extent that they seemed more suited to detection of specific structures. We would speculate that the broadly varying forms of cat cortical receptive fields result from developmental processes akin to those that form ocular-dominance columns, but on a smaller scale.

Dynamic aspects of receptive field organization in area VI of the macaque monkey

1992 ◽  
pp. 177-188
Author(s):  
James M. Fox ◽  
David C. Van Essen ◽  
Tobias Delbrück ◽  
Jack Gallant ◽  
Charles H. Anderson
Keyword(s):  
Receptive Field ◽  
Macaque Monkey ◽  
Field Organization ◽  
Receptive Field Organization

Cortex Controls Multisensory Depression in Superior Colliculus

2003 ◽  
Vol 90 (4) ◽  
pp. 2123-2135 ◽  
Author(s):  
Wan Jiang ◽  
Barry E. Stein
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Multisensory Integration ◽  
Auditory Stimulus ◽  
Visual Stimulus ◽  
Sensory Stimulus ◽  
Visual Orientation ◽  
Orientation Behavior ◽  
Cortical Areas

Multisensory depression is a fundamental index of multisensory integration in superior colliculus (SC) neurons. It is initiated when one sensory stimulus (auditory) located outside its modality-specific receptive field degrades or eliminates the neuron's responses to another sensory stimulus (visual) presented within its modality-specific receptive field. The present experiments demonstrate that the capacity of SC neurons to engage in multisensory depression is strongly dependent on influences from two cortical areas (the anterior ectosylvian and rostral lateral suprasylvian sulci). When these cortices are deactivated, the ability of SC neurons to synthesize visual-auditory inputs in this way is compromised; multisensory responses are disinhibited, becoming more vigorous and in some cases indistinguishable from responses to the visual stimulus alone. Although obtaining a more robust multisensory SC response when cortex is nonfunctional than when it is functional may seem paradoxical, these data may help explain previous observations that the loss of these cortical influences permits visual orientation behavior in the presence of a normally disruptive auditory stimulus.

Effects of nerve injury on sympathetic excitation of A delta mechanical nociceptors

1995 ◽  
Vol 73 (4) ◽  
pp. 1721-1723 ◽  
Author(s):  
D. F. Bossut ◽  
E. R. Perl
Keyword(s):  
Receptive Field ◽  
Nerve Injury ◽  
High Threshold ◽  
Myelinated Fiber ◽  
Mechanical Stimuli ◽  
Sympathetic Stimulation ◽  
Great Auricular Nerve ◽  
C Fiber ◽  
Field Organization ◽  
Receptive Field Organization

1. The effects of sympathetic stimulation and close arterial injection of norepinephrine were tested on cutaneous myelinated-fiber (A delta) mechanical nociceptors [high-threshold mechanoreceptors-(MyHTMs)] from normal and from partially transsected nerves. 2. Neither sympathetic stimulation nor close arterial injection of norepinephrine (200 ng) excited MyHTMs (18) recorded from the uninjured great auricular nerve of adult rabbits. 3. MyHTMs (58) conducting across the site of partial cut lesions, made 2 to 28 days previously, had threshold and responsiveness to mechanical stimuli, receptive field organization, and absence of background discharge typical of such elements in normal nerve. 4. Four MyHTMs recorded from the injured nerves were excited by sympathetic stimulation and/or norepinephrine injection but only one gave more than two impulses within 60 s to either form of stimulation. 5. The meagerness of the sympathetic and adrenergic excitation of MyHTMs after nerve injury contrasts with that observed under similar conditions for C-fiber polymodal nociceptors. Therefore, induction of adrenergic responsiveness in nociceptors after partial denervation in cutaneous MyHTMs appears to be less important for mechanisms related to pathogenic pain than alterations in certain C-fiber nociceptors.

Sign in / Sign up

Export Citation Format

Share Document