scholarly journals Visual response latencies of magnocellular and parvocellular LGN neurons in macaque monkeys

1999 ◽  
Vol 16 (1) ◽  
pp. 1-14 ◽  
Author(s):  
JOHN H.R. MAUNSELL ◽  
GEOFFREY M. GHOSE ◽  
JOHN A. ASSAD ◽  
CARRIE J. McADAMS ◽  
CHRISTEN ELIZABETH BOUDREAU ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Visual Response ◽  
Relative Timing ◽  
Relative Speed ◽  
Visual Responses ◽  
Response Latencies ◽  
Macaque Monkeys ◽  
Wide Range ◽  
Neurophysiological Data ◽  
Parvocellular Neurons

Signals relayed through the magnocellular layers of the LGN travel on axons with faster conduction speeds than those relayed through the parvocellular layers. As a result, magnocellular signals might reach cerebral cortex appreciably before parvocellular signals. The relative speed of these two channels cannot be accurately predicted based solely on axon conduction speeds, however. Other factors, such as different degrees of convergence in the magnocellular and parvocellular channels and the retinal circuits that feed them, can affect the time it takes for magnocellular and parvocellular signals to activate cortical neurons. We have investigated the relative timing of visual responses mediated by the magnocellular and parvocellular channels. We recorded individually from 78 magnocellular and 80 parvocellular neurons in the LGN of two anesthetized monkeys. Visual response latencies were measured for small spots of light of various intensities. Over a wide range of stimulus intensities the fastest magnocellular response latencies preceded the fastest parvocellular response latencies by about 10 ms. Because parvocellular neurons are far more numerous than magnocellular neurons, convergence in cortex could reduce the magnocellular advantage by allowing parvocellular signals to generate detectable responses sooner than expected based on the responses of individual parvocellular neurons. An analysis based on a simple model using neurophysiological data collected from the LGN shows that convergence in cortex could eliminate or reverse the magnocellular advantage. This observation calls into question inferences that have been made about ordinal relationships of neurons based on timing of responses.

Visual Response Properties of Neurons in the LGN of Normally Reared and Visually Deprived Macaque Monkeys

2001 ◽  
Vol 85 (5) ◽  
pp. 2111-2129 ◽  
Author(s):  
Jonathan B. Levitt ◽  
Robert A. Schumer ◽  
S. Murray Sherman ◽  
Peter D. Spear ◽  
J. Anthony Movshon
Keyword(s):  
Receptive Field ◽  
Receptive Fields ◽  
Optic Chiasm ◽  
Monocular Deprivation ◽  
Specific Cell ◽  
Visual Response ◽  
Response Latencies ◽  
Macaque Monkeys ◽  
Response Properties ◽  
Parvocellular Neurons

It is now well appreciated that parallel retino-geniculo-cortical pathways exist in the monkey as in the cat, the species in which parallel visual pathways were first and most thoroughly documented. What remains unclear is precisely how many separate pathways pass through the parvo- and magnocellular divisions of the macaque lateral geniculate nucleus (LGN), what relationships—homologous or otherwise—these pathways have to the cat's X, Y, and W pathways, and whether these are affected by visual deprivation. To address these issues of classification and trans-species comparison, we used achromatic stimuli to obtain an extensive set of quantitative measurements of receptive field properties in the parvo- and magnocellular laminae of the LGN of nine macaque monkeys: four normally reared and five monocularly deprived of vision by lid suture near the time of birth. In agreement with previous studies, we find that on average magnocellular neurons differ from parvocellular neurons by having shorter response latencies to optic chiasm stimulation, greater sensitivity to luminance contrast, and better temporal resolution. Magnocellular laminae are also distinguished by containing neurons that summate luminance over their receptive fields nonlinearly (Y cells) and whose temporal response phases decrease with increasing stimulus contrast (indicative of a contrast gain control mechanism). We found little evidence for major differences between magno- and parvocellular neurons on the basis of most spatial parameters except that at any eccentricity, the neurons with the smallest receptive field centers tended to be parvocellular. All parameters were distributed unimodally and continuously through the parvo- and magnocellular populations, giving no indications of subpopulations within each division. Monocular deprivation led to clear anatomical effects: cells in deprived-eye laminae were pale and shrunken compared with those in nondeprived eye laminae, and Cat-301 immunoreactivity in deprived laminae was essentially uniformly abolished. However, deprivation had only subtle effects on the response properties of LGN neurons. Neurons driven by the deprived eye in both magno- and parvocellular laminae had lower nonlinearity indices (i.e., summed signals across their receptive fields more linearly) and were somewhat less responsive. In magnocellular laminae driven by the deprived eye, neuronal response latencies to stimulation of the optic chiasm were slightly shorter than those in the nondeprived laminae, and receptive field surrounds were a bit stronger. No other response parameters were affected by deprivation, and there was no evidence for loss of a specific cell class as in the cat.

scholarly journals Altered functional interactions between neurons in primary visual cortex of macaque monkeys with experimental amblyopia

2019 ◽  
Author(s):  
Katerina Acar ◽  
Lynne Kiorpes ◽  
J. Anthony Movshon ◽  
Matthew A. Smith
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Cortical Neurons ◽  
Visual Sensitivity ◽  
Visual Responses ◽  
Macaque Monkeys ◽  
Fellow Eye ◽  
Neuronal Populations ◽  
Evoked Activity

AbstractAmblyopia, a disorder in which vision through one of the eyes is degraded, arises because of defective processing of information by the visual system. Amblyopia often develops in humans after early misalignment of the eyes (strabismus), and can be simulated in macaque monkeys by artificially inducing strabismus. In such amblyopic animals, single-unit responses in primary visual cortex (V1) are appreciably reduced when evoked by the amblyopic eye compared to the other (fellow) eye. However, this degradation in single V1 neuron responsivity is not commensurate with the marked losses in visual sensitivity and resolution measured behaviorally. Here we explored the idea that changes in patterns of coordinated activity across populations of V1 neurons may contribute to degraded visual representations in amblyopia, potentially making it more difficult to read out evoked activity to support perceptual decisions. We studied the visually-evoked activity of V1 neuronal populations in three macaques (M. nemestrina) with strabismic amblyopia and in one control. Activity driven through the amblyopic eye was diminished, and these responses also showed more interneuronal correlation at all stimulus contrasts than responses driven through the fellow eye or responses in the control. A decoding analysis showed that responses driven through the amblyopic eye carried less visual information than other responses. Our results suggest that part of the reduced visual capacity of amblyopes may be due to changes in the patterns of functional interaction among neurons in V1.New and noteworthyAmblyopia is a developmental disorder of visual processing that reduces visual function and changes the visual responses of cortical neurons in macaque monkeys. The neuronal and behavioral changes are not always well correlated. We found that the interactions among neurons in the visual cortex of monkeys with amblyopia are also altered. These changes may contribute to amblyopic visual deficits by diminishing the amount of information relayed by neuronal populations driven by the amblyopic eye.

Pulvinar nuclei of the behaving rhesus monkey: visual responses and their modulation

1985 ◽  
Vol 54 (4) ◽  
pp. 867-886 ◽  
Author(s):  
S. E. Petersen ◽  
D. L. Robinson ◽  
W. Keys
Keyword(s):  
Discharge Rate ◽  
Receptive Fields ◽  
Stimulus Onset ◽  
Visual Response ◽  
Visual Responses ◽  
Response Latencies ◽  
Stimulus Movement ◽  
Selective Visual Attention ◽  
Retinotopic Organization ◽  
A Cell

We have examined the properties of neurons in three subdivisions of the pulvinar of alert, trained rhesus monkeys 1) an inferior, retinotopically mapped area (PI), 2) a lateral, retinotopically organized region (PL), and 3) a dorsomedial visual portion of the lateral pulvinar (Pdm), which has a crude retinotopic organization. We tested the neurons for visual responses to stationary and moving stimuli and for changes in these responses produced by behavioral manipulations. All areas contain cells sensitive to stimulus orientation as well as neurons selective for the direction of stimulus movement; however, the majority of cells in all three regions are either broadly tuned or nonselective for these attributes. Nearly all cells respond to stimulus onset, a significant number also give a response to stimulus termination, and rarely a cell gives only off responses. Nearly all cells increase their discharge rate to visual stimuli. Receptive fields in the two retinotopically mapped regions, PI and PL, have well-defined borders. The sizes of these receptive fields show a positive correlation with the eccentricity of the receptive fields. The receptive fields in the remaining region, Pdm, are frequently very large, but with these large fields excluded, show a similar correlation with eccentricity. All pulvinar cells tested (n = 20) were mapped in retinal coordinates; the receptive fields are positioned in relation to the retina. We found no cells with gaze-gated characteristics (2), nor cells mapped in a spatial coordinate system. The response latencies in PI and PL are shorter and less variable than the latencies in Pdm. Active use of a stimulus can produce an enhancement or attenuation of the visual response. Eye-movement modulation was found in all three subdivisions in about equal frequencies. Attentional modulation was common in Pdm and was rare in PI and PL. The modulation is spatially selective in Pdm and nonselective in PI for a small number of tested cells. These data demonstrate functional differences between Pdm and the other two areas and suggest that Pdm plays a role in selective visual attention, whereas PI and PL probably contribute to other aspects of visual perception.

Signal Timing Across the Macaque Visual System

1998 ◽  
Vol 79 (6) ◽  
pp. 3272-3278 ◽  
Author(s):  
Matthew T. Schmolesky ◽  
Youngchang Wang ◽  
Doug P. Hanes ◽  
Kirk G. Thompson ◽  
Stefan Leutgeb ◽  
...  
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Time Course ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Frontal Eye Field ◽  
Signal Timing ◽  
Visual Response ◽  
Visual Responses ◽  
Response Latencies ◽  
Temporal Area

Schmolesky, Matthew T., Youngchang Wang, Doug P. Hanes, Kirk G. Thompson, Stefan Leutgeb, Jeffrey D. Schall, and Audie G. Leventhal. Signal timing across the macaque visual system. J. Neurophysiol. 79: 3272–3278, 1998. The onset latencies of single-unit responses evoked by flashing visual stimuli were measured in the parvocellular (P) and magnocellular (M) layers of the dorsal lateral geniculate nucleus (LGNd) and in cortical visual areas V1, V2, V3, V4, middle temporal area (MT), medial superior temporal area (MST), and in the frontal eye field (FEF) in individual anesthetized monkeys. Identical procedures were carried out to assess latencies in each area, often in the same monkey, thereby permitting direct comparisons of timing across areas. This study presents the visual flash-evoked latencies for cells in areas where such data are common (V1 and V2), and are therefore a good standard, and also in areas where such data are sparse (LGNd M and P layers, MT, V4) or entirely lacking (V3, MST, and FEF in anesthetized preparation). Visual-evoked onset latencies were, on average, 17 ms shorter in the LGNd M layers than in the LGNd P layers. Visual responses occurred in V1 before any other cortical area. The next wave of activation occurred concurrently in areas V3, MT, MST, and FEF. Visual response latencies in areas V2 and V4 were progressively later and more broadly distributed. These differences in the time course of activation across the dorsal and ventral streams provide important temporal constraints on theories of visual processing.

scholarly journals Binocular vs. monocular recovery experience differentially promote recovery from visual deficits in a mouse model of amblyopia

2021 ◽  
Author(s):  
Jessy D. Martinez ◽  
Marcus J. Donnelly ◽  
Donald S. Popke ◽  
Daniel Torres ◽  
Sarah Sheskey ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Mouse Model ◽  
Cortical Neurons ◽  
Visual Experience ◽  
Monocular Deprivation ◽  
Visual Response ◽  
Partial Recovery ◽  
Visual Responses ◽  
V1 Neurons ◽  
Dominant Eye

AbstractAltered visual experience during monocular deprivation (MD) profoundly changes in ocular dominance (OD) in the developing primary visual cortex (V1). MD-driven changes in OD are an experimental model of amblyopia, where early-life alterations in vision lead visual disruption in adulthood. Current treatments for amblyopia include patching of the dominant eye, and more recently-developed binocular therapies. However, the relative impact of monocular vs. binocular recovery experiences on recovery of function in V1 is not well understood. Using single-unit recording, we compared how binocular recovery [BR] or reverse occlusion [RO] of identical duration and content affects OD and visual response recovery in mouse binocular V1 after a period of MD. We also tested how BR and RO affected MD-driven alterations of parvalbumin expression, and visually-driven expression of cFos in parvalbumin-positive and negative neurons. Finally, we tested how BR and RO affected recovery of normal visual acuity for the two eyes in the context of visually-driven behavior. We find that BR is quantitatively superior with respect to normalization of V1 neurons’ OD, visually-driven cFos expression, and visual acuity for the two eyes. However, MD-driven changes in the firing rate and response properties of V1 principal neuron and fast-spiking interneuron populations do not recover fully after either BR or RO. Binocular matching of orientation preference also remains disrupted in V1 neurons after both forms of recovery experience. Thus BR and RO, analogs of differing treatment regimens for amblyopia, differentially impact various aspects of visual recovery in a mouse model for amblyopia.Significance StatementAmblyopia resulting from altered childhood eye function is a leading cause of lifelong vision loss. Treatment typically involves patching of the dominant eye (forcing monocular visual experience), and produces only partial recovery of vision. Using a well-established mouse model of amblyopia, we directly compared how two types of visual experiences influence recovery of visual function. Our findings suggest that binocular vs. monocular visual experience differentially effect restoration of normal visual responses in cortical neurons, visually-driven neuronal gene expression, and visual acuity. Understanding how the quality of recovery experience impacts visual system recovery in amblyopia should provide critical insights for clinical strategies for its treatment.

scholarly journals Visual response of ventrolateral prefrontal neurons and their behavior-related modulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefano Rozzi ◽  
Marco Bimbi ◽  
Alfonso Gravante ◽  
Luciano Simone ◽  
Leonardo Fogassi
Keyword(s):  
Visual Cues ◽  
Visual Stimuli ◽  
Visual Response ◽  
Visual Responses ◽  
Action Execution ◽  
Natural Behavior ◽  
Large Sector ◽  
Small Set ◽  
Early Passive ◽  
Task Conditions

AbstractThe ventral part of lateral prefrontal cortex (VLPF) of the monkey receives strong visual input, mainly from inferotemporal cortex. It has been shown that VLPF neurons can show visual responses during paradigms requiring to associate arbitrary visual cues to behavioral reactions. Further studies showed that there are also VLPF neurons responding to the presentation of specific visual stimuli, such as objects and faces. However, it is largely unknown whether VLPF neurons respond and differentiate between stimuli belonging to different categories, also in absence of a specific requirement to actively categorize or to exploit these stimuli for choosing a given behavior. The first aim of the present study is to evaluate and map the responses of neurons of a large sector of VLPF to a wide set of visual stimuli when monkeys simply observe them. Recent studies showed that visual responses to objects are also present in VLPF neurons coding action execution, when they are the target of the action. Thus, the second aim of the present study is to compare the visual responses of VLPF neurons when the same objects are simply observed or when they become the target of a grasping action. Our results indicate that: (1) part of VLPF visually responsive neurons respond specifically to one stimulus or to a small set of stimuli, but there is no indication of a “passive” categorical coding; (2) VLPF neuronal visual responses to objects are often modulated by the task conditions in which the object is observed, with the strongest response when the object is target of an action. These data indicate that VLPF performs an early passive description of several types of visual stimuli, that can then be used for organizing and planning behavior. This could explain the modulation of visual response both in associative learning and in natural behavior.

Organization of local horizontal functional interactions between neurons in the inferior temporal cortex of macaque monkeys

2014 ◽  
Vol 111 (12) ◽  
pp. 2589-2602 ◽  
Author(s):  
Hiroshi Tamura ◽  
Yoshiya Mori ◽  
Hidekazu Kaneko
Keyword(s):  
Neuronal Activity ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Visual Object ◽  
Detailed Knowledge ◽  
Visual Response ◽  
Stimulus Preference ◽  
Macaque Monkeys ◽  
Functional Interactions ◽  
Cross Correlation Analysis

Detailed knowledge of neuronal circuitry is necessary for understanding the mechanisms underlying information processing in the brain. We investigated the organization of horizontal functional interactions in the inferior temporal cortex of macaque monkeys, which plays important roles in visual object recognition. Neuronal activity was recorded from the inferior temporal cortex using an array of eight tetrodes, with spatial separation between paired neurons up to 1.4 mm. We evaluated functional interactions on a time scale of milliseconds using cross-correlation analysis of neuronal activity of the paired neurons. Visual response properties of neurons were evaluated using responses to a set of 100 visual stimuli. Adjacent neuron pairs tended to show strong functional interactions compared with more distant neuron pairs, and neurons with similar stimulus preferences tended to show stronger functional interactions than neurons with different stimulus preferences. Thus horizontal functional interactions in the inferior temporal cortex appear to be organized according to both cortical distances and similarity in stimulus preference between neurons. Furthermore, the relationship between strength of functional interactions and similarity in stimulus preference observed in distant neuron pairs was more prominent than in adjacent pairs. The results suggest that functional circuitry is specifically organized, depending on the horizontal distances between neurons. Such specificity endows each circuit with unique functions.

Representation of Spectral and Temporal Envelope of Twitter Vocalizations in Common Marmoset Primary Auditory Cortex

2002 ◽  
Vol 87 (4) ◽  
pp. 1723-1737 ◽  
Author(s):  
Srikantan S. Nagarajan ◽  
Steven W. Cheung ◽  
Purvis Bedenbaugh ◽  
Ralph E. Beitel ◽  
Christoph E. Schreiner ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Social Contact ◽  
Primary Auditory Cortex ◽  
Common Marmoset ◽  
Spectral Envelope ◽  
Response Patterns ◽  
Temporal Envelope ◽  
Degraded Speech ◽  
Neurophysiological Data ◽  
Narrowband Channels

Cortical sensitivity in representations of behaviorally relevant complex input signals was examined in recordings from primary auditory cortical neurons (AI) in adult, barbiturate-anesthetized common marmoset monkeys ( Callithrix jacchus). We studied the robustness of distributed responses to natural and degraded forms of twitter calls, social contact vocalizations comprising several quasi-periodic phrases of frequency and AM. We recorded neuronal responses to a monkey's own twitter call (MOC), degraded forms of their twitter call, and sinusoidal amplitude modulated (SAM) tones with modulation rates similar to those of twitter calls. In spectral envelope degradation, calls with narrowband channels of varying bandwidths had the same temporal envelope as a natural call. However, the carrier phase was randomized within each narrowband channel. In temporal envelope degradation, the temporal envelope within narrowband channels was filtered while the carrier frequencies and phases remained unchanged. In a third form of degradation, noise was added to the natural calls. Spatiotemporal discharge patterns in AI both within and across frequency bands encoded spectrotemporal acoustic features in the call although the encoded response is an abstract version of the call. The average temporal response pattern in AI, however, was significantly correlated with the average temporal envelope for each phrase of a call. Response entrainment to MOC was significantly correlated with entrainment to SAM stimuli at comparable modulation frequencies. Sensitivity of the response patterns to MOC was substantially greater for temporal envelope than for spectral envelope degradations. The distributed responses in AI were robust to additive continuous noise at signal-to-noise ratios ≥10 dB. Neurophysiological data reflecting response sensitivity in AI to these forms of degradation closely parallel human psychophysical results on the intelligibility of degraded speech in quiet and noisy conditions.

Sign in / Sign up

Export Citation Format

Share Document