scholarly journals The foveal visual representation of the primate superior colliculus

2019 ◽  
Author(s):  
Chih-Yang Chen ◽  
Klaus-Peter Hoffmann ◽  
Claudia Distler ◽  
Ziad M. Hafed
Keyword(s):  
Superior Colliculus ◽  
Visual Representation ◽  
Scene Analysis ◽  
Gaze Shifts ◽  
Retinal Input ◽  
Highly Sensitive ◽  
Specific Manner ◽  
Visual Tasks ◽  
High Acuity ◽  
Visual Cortices

AbstractProcessing of foveal retinal input is important not only for high quality visual scene analysis, but also for ensuring precise, albeit tiny, gaze shifts during high acuity visual tasks. The representations of foveal retinal input in primate lateral geniculate nucleus and early visual cortices have been characterized. However, how such representations translate into precise eye movements remains unclear. Here we document functional and structural properties of the foveal visual representation of midbrain superior colliculus. We show that superior colliculus, classically associated with extra-foveal spatial representations needed for gaze shifts, is highly sensitive to visual input impinging on the fovea. Superior colliculus also represents such input in an orderly and very specific manner, and it magnifies representation of foveal images in neural tissue as much as primary visual cortex does. Primate superior colliculus contains a high-fidelity visual representation, with large foveal magnification, perfectly suited for active visuomotor control and perception.

scholarly journals Role of the Primate Superior Colliculus in the Control of Head Movements

2007 ◽  
Vol 98 (4) ◽  
pp. 2022-2037 ◽  
Author(s):  
Mark M. G. Walton ◽  
Bernard Bechara ◽  
Neeraj J. Gandhi
Keyword(s):  
Superior Colliculus ◽  
Firing Rate ◽  
Head Movements ◽  
Neural Basis ◽  
Average Firing Rate ◽  
Gaze Shifts ◽  
Burst Neurons ◽  
The Gaze ◽  
Head Displacement ◽  
Elevated Frequency

One important behavioral role for head movements is to assist in the redirection of gaze. However, primates also frequently make head movements that do not involve changes in the line of sight. Virtually nothing is known about the neural basis of these head-only movements. In the present study, single-unit extracellular activity was recorded from the superior colliculus while monkeys performed behavioral tasks that permit the temporal dissociation of gaze shifts and head movements. We sought to determine whether superior colliculus contains neurons that modulate their activity in association with head movements in the absence of gaze shifts and whether classic gaze-related burst neurons also discharge for head-only movements. For 26% of the neurons in our sample, significant changes in average firing rate could be attributed to head-only movements. Most of these increased their firing rate immediately prior to the onset of a head movement and continued to discharge at elevated frequency until the offset of the movement. Others discharged at a tonic rate when the head was stable and decreased their activity, or paused, during head movements. For many putative head cells, average firing rate was found to be predictive of head displacement. Some neurons exhibited significant changes in activity associated with gaze, eye-only, and head-only movements, although none of the gaze-related burst neurons significantly modulated its activity in association with head-only movements. These results suggest the possibility that the superior colliculus plays a role in the control of head movements independent of gaze shifts.

scholarly journals Influence of adult Schwann cells and olfactory ensheathing glia on axontarget cell interactions in the CNS a comparative analysis using a retinotectal cograft model

2007 ◽  
Vol 3 (2) ◽  
pp. 105-117 ◽  
Author(s):  
Jana Vukovic ◽  
Giles W. Plant ◽  
Marc J. Ruitenberg ◽  
Alan R. Harvey
Keyword(s):  
Superior Colliculus ◽  
Schwann Cells ◽  
Fluorescent Protein ◽  
Cell Interactions ◽  
Minimal Impact ◽  
Pathway Reconstruction ◽  
Retinal Input ◽  
Olfactory Ensheathing Glia ◽  
Green Fluorescent

AbstractWe used an in vivo transplant approach to examine how adult Schwann cells and olfactory ensheathing glia OEG influence the specificity of axontarget cell interactions when they are introduced into the CNS. Populations of either Schwann cells or OEG were mixed with dissociated fetal tectal cells presumptive superior colliculus and, after reaggregation, pieces were grafted onto newborn rat superior colliculus. Both glial types were prelabeled with lentiviral vectors encoding green fluorescent protein. Grafts rapidly established fiber connections with the host and retinal projections into cografts were assessed 656 days posttransplantation by injecting cholera toxinB into host eyes. In control rats that received pure dissociatedreaggregated tectal grafts, retinal ganglion cell RGC axons selectively innervated defined target areas, corresponding to the retinorecipient layer in normal superior colliculus. The pattern of RGC axon ingrowth into OEG containing cografts was similar to that in control grafts. However, in Schwann cell cografts there was reduced host retinal input into presumptive target areas and many RGC axons were scattered throughout the neuropil. Given that OEG in cografts had minimal impact on axontarget cell recognition, OEG might be an appropriate cell type for direct transplantation into injured neuropil when attempting to stimulate specific pathway reconstruction.

Movement of neural activity on the superior colliculus motor map during gaze shifts

Science ◽  
1991 ◽  
Vol 251 (4999) ◽  
pp. 1358-1360 ◽  
Author(s):  
D. Munoz ◽  
D Pelisson ◽  
D Guitton
Keyword(s):  
Superior Colliculus ◽  
Neural Activity ◽  
Gaze Shifts

A reciprocal connection between the ventral lateral geniculate nucleus and the pretectal nuclear complex and the superior colliculus: Anin vitrocharacterization in the rat

2008 ◽  
Vol 25 (1) ◽  
pp. 39-51 ◽  
Author(s):  
GESCHE BORN ◽  
MATTHIAS SCHMIDT
Keyword(s):  
Superior Colliculus ◽  
Lateral Geniculate Nucleus ◽  
Brain Slices ◽  
Double Labeling ◽  
Nuclear Complex ◽  
Lateral Geniculate ◽  
Retinal Input ◽  
Strongly Connected ◽  
Tectal Neurons

The ventral lateral geniculate nucleus (vLGN), the pretectal nuclear complex (PNC) and the superior colliculus (SC) are structures that all receive retinal input. All three structures are important relay stations of the subcortical visual system. They are strongly connected with each other and involved in circadian and/or visuomotor processes. However, the information transferred along these pathways is unknown and their possible functions are, therefore, not well understood. Here, we characterized multiple pathways between the vLGN, the PNC, and the SC electrophysiologically and anatomically in anin vitrostudy using acute rat brain slices. Using orthodromic and antidromic electrical stimulation, we first characterized vLGN neurons that receive pretectal input and those that project to the PNC. Morphological reconstructions of cells labeled after patch clamp recordings identified these neurons as geniculo-tectal neurons and as medium-sized multipolar neurons. We identified inhibitory connections in both pathways and we could show that inhibitory postsynaptic currents (IPSCs) evoked from the PNC in vLGN neurons are mediated only by GABAAreceptors, while IPSCs evoked in PNC neurons by vLGN stimulation are either mediated by both, GABAAand GABACreceptors or by a GABA receptor with mixed GABAAand GABACreceptor-like pharmacology. Finally, retrograde double labeling experiments with two different fluorescent dextran amines indicated that pretectal neurons which project to the ipsilateral vLGN also project to the ipsilateral SC.

scholarly journals Cortical inactivation does not block response enhancement in the superior colliculus

2020 ◽  
Author(s):  
Katarzyna Kordecka ◽  
Andrzej T. Foik ◽  
Agnieszka Wierzbicka ◽  
Wioletta J. Waleszczyk
Keyword(s):  
Visual System ◽  
Superior Colliculus ◽  
Visual Stimulation ◽  
Training Session ◽  
Cortical Circuits ◽  
Visual Training ◽  
Sensory Stimuli ◽  
Visual Tasks ◽  
Response Enhancement ◽  
Positive Results

AbstractRepetitive visual stimulation is successfully used in a study on the visual evoked potential (VEP) plasticity in the visual system in mammals. Practicing visual tasks or repeated exposure to sensory stimuli can induce neuronal network changes in the cortical circuits and improve the perception of these stimuli. However little is known about the effect of visual training at the subcortical level. In the present study, we extend the knowledge showing positive results of this training in the rat’s superior colliculus (SC). In electrophysiological experiments, we showed that a single training session lasting several hours induces a response enhancement both in the primary visual cortex (V1) and in the SC. Further, we tested if collicular responses will be enhanced without V1 input. For this reason, we inactivated the V1 by applying xylocaine solution onto the cortical surface during visual training. Our results revealed that SC’s response enhancement was present even without V1 inputs and showed no difference in amplitude comparing to VEPs enhancement while the V1 was active. These data suggest that the visual system plasticity and facilitation can develop independently but simultaneously in different parts of the visual system.

scholarly journals A Modular Microarray Imaging System for Highly Specific COVID-19 Antibody Testing

2020 ◽  
Author(s):  
Per Niklas Hedde ◽  
Timothy J. Abram ◽  
Aarti Jain ◽  
Rie Nakajima ◽  
Rafael Ramiro de Assis ◽  
...  
Keyword(s):  
Large Scale ◽  
Imaging System ◽  
Turnaround Time ◽  
Mitigation Measures ◽  
Antibody Testing ◽  
Imaging Device ◽  
Highly Sensitive ◽  
Finger Prick ◽  
Specific Manner ◽  
To Come

AbstractTo detect the presence of antibodies in blood against SARS-CoV-2 in a highly sensitive and specific manner, here we describe a robust, inexpensive ($200), 3D-printable portable imaging platform (TinyArray imager) that can be deployed immediately in areas with minimal infrastructure to read coronavirus antigen microarrays (CoVAMs) that contain a panel of antigens from SARS-CoV-2, SARS-1, MERS, and other respiratory viruses. Application includes basic laboratories and makeshift field clinics where a few drops of blood from a finger prick could be rapidly tested in parallel for the presence of antibodies to SARS-CoV-2 with a test turnaround time of only 2-4 h. To evaluate our imaging device, we probed and imaged coronavirus microarrays with COVID-19-positive and negative sera and achieved a performance on par with a commercial microarray reader 100x more expensive than our imaging device. This work will enable large scale serosurveillance, which can play an important role in the months and years to come to implement efficient containment and mitigation measures, as well as help develop therapeutics and vaccines to treat and prevent the spread of COVID-19.

scholarly journals Functional and structural organization of the foveal visual representation of the primate superior colliculus

2017 ◽  
Vol 17 (10) ◽  
pp. 739
Author(s):  
Chih-Yang Chen ◽  
Claudia Distler ◽  
Klaus-Peter Hoffmann ◽  
Ziad Hafed
Keyword(s):  
Superior Colliculus ◽  
Structural Organization ◽  
Visual Representation

scholarly journals Activity of Cells in the Deeper Layers of the Superior Colliculus of the Rhesus Monkey: Evidence for a Gaze Displacement Command

1997 ◽  
Vol 78 (3) ◽  
pp. 1669-1690 ◽  
Author(s):  
Edward G. Freedman ◽  
David L. Sparks
Keyword(s):  
Eye Movements ◽  
Rhesus Monkey ◽  
Superior Colliculus ◽  
Single Cells ◽  
Head Movements ◽  
Gaze Shifts ◽  
Unit Recording ◽  
The Gaze ◽  
Head Displacement ◽  
Separate Channel

Freedman, Edward G. and David L. Sparks. Activity of cells in the deeper layers of the superior colliculus of the rhesus monkey: evidence for a gaze displacement command. J. Neurophysiol. 78: 1669–1690, 1997. When the head is free to move, microstimulation of the primate superior colliculus (SC) evokes coordinated movements of the eyes and head. The similarity between these stimulation-induced movements and visually guided movements indicates that the SC of the primate is involved in redirecting the line of sight (gaze). To determine how movement commands are represented by individual collicular neurons, we recorded the activity of single cells in the deeper layers of the superior colliculus of the rhesus monkey during coordinated eye-head gaze shifts. Two alternative hypotheses were tested. The “separate channel” hypothesis states that two displacement commands are generated by the SC: one signal specifying the amplitude and direction of eye movements and a second signal specifying the amplitude and direction of head movements. Alternatively, a single gaze displacement command could be generated by the SC (“gaze displacement” hypothesis). The activity of collicular neurons was examined during three behavioral dissociations of gaze, eye, and head movement amplitude and direction (metrics). Subsets of trials were selected in which the amplitude and direction of either gaze shifts or eye movements or head movements were relatively constant but the metrics of the other two varied over wide ranges. Under these conditions, the separate channel and gaze displacement hypotheses make differential predictions about the patterns of SC activity. We tested these differential predictions by comparing observed patterns with predicted patterns of neuronal activity. We obtained data consistent with the predictions of the gaze displacement hypothesis. The predictions of the separate channel hypothesis were not confirmed. Thus microstimulation data, single-unit recording data, and behavioral data are all consistent with the gaze displacement hypothesis of collicular function—the hypothesis that a gaze displacement signal is derived from the locus of activity within the motor map of the SC and subsequently is decomposed into separate eye and head displacement signals downstream from the colliculus.

scholarly journals Effect of Reversible Inactivation of Superior Colliculus on Head Movements

2008 ◽  
Vol 99 (5) ◽  
pp. 2479-2495 ◽  
Author(s):  
Mark M. G. Walton ◽  
Bernard Bechara ◽  
Neeraj J. Gandhi
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Movement Control ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Reversible Inactivation ◽  
The Gaze ◽  
Made In

Because of limitations in the oculomotor range, many gaze shifts must be accomplished using coordinated movements of the eyes and head. Stimulation and recording data have implicated the primate superior colliculus (SC) in the control of these gaze shifts. The precise role of this structure in head movement control, however, is not known. The present study uses reversible inactivation to gain insight into the role of this structure in the control of head movements, including those that accompany gaze shifts and those that occur in the absence of a change in gaze. Forty-five lidocaine injections were made in two monkeys that had been trained on a series of behavioral tasks that dissociate movements of the eyes and head. Reversible inactivation resulted in clear impairments in the animals’ ability to perform gaze shifts, manifested by increased reaction times, lower peak velocities, and increased durations. In contrast, comparable effects were not found for head movements (with or without gaze shifts) with the exception of a very small increase in reaction times of head movements associated with gaze shifts. Eye-head coordination was clearly affected by the injections with gaze onset occurring relatively later with respect to head onset. Following the injections, the head contributed slightly more to the gaze shift. These results suggest that head movements (with and without gaze shifts) can be controlled by pathways that do not involve SC.

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