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Street JS, Jeffery KJ. The dorsal thalamic lateral geniculate nucleus is required for visual control of head direction cell firing direction in rats. J Physiol 2024. [PMID: 39235958 DOI: 10.1113/jp286868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 08/13/2024] [Indexed: 09/07/2024] Open
Abstract
Head direction (HD) neurons, signalling facing direction, generate a signal that is primarily anchored to the outside world by visual inputs. We investigated the route for visual landmark information into the HD system in rats. There are two candidates: an evolutionarily older, larger subcortical retino-tectal pathway and a more recently evolved, smaller cortical retino-geniculo-striate pathway. We disrupted the cortical pathway by lesioning the dorsal lateral geniculate thalamic nuclei bilaterally, and recorded HD cells in the postsubicular cortex as rats foraged in a visual-cue-controlled enclosure. In lesioned rats we found the expected number of postsubicular HD cells. Although directional tuning curves were broader across a trial, this was attributable to the increased instability of otherwise normal-width tuning curves. Tuning curves were also poorly responsive to polarizing visual landmarks and did not distinguish cues based on their visual pattern. Thus, the retino-geniculo-striate pathway is not crucial for the generation of an underlying, tightly tuned directional signal but does provide the main route for vision-based anchoring of the signal to the outside world, even when visual cues are high in contrast and low in detail. KEY POINTS: Head direction (HD) cells indicate the facing direction of the head, using visual landmarks to distinguish directions. In rats, we investigated whether this visual information is routed through the thalamus to the visual cortex or arrives via the superior colliculus, which is a phylogenetically older and (in rodents) larger pathway. We lesioned the thalamic dorsal lateral geniculate nucleus (dLGN) in rats and recorded the responsiveness of cortical HD cells to visual cues. We found that cortical HD cells had normal tuning curves, but these were slightly more unstable during a trial. Most notably, HD cells in dLGN-lesioned animals showed little ability to distinguish highly distinct cues and none to distinguish more similar cues. These results suggest that directional processing of visual landmarks in mammals requires the geniculo-cortical pathway, which raises questions about when and how visual directional landmark processing appeared during evolution.
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Affiliation(s)
- James S Street
- Institute of Neurology, University College London, London, UK
| | - Kate J Jeffery
- School of Psychology & Neuroscience, University of Glasgow, Glasgow, UK
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2
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Palanker D. Electronic Retinal Prostheses. Cold Spring Harb Perspect Med 2023; 13:a041525. [PMID: 36781222 PMCID: PMC10411866 DOI: 10.1101/cshperspect.a041525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Retinal prostheses are a promising means for restoring sight to patients blinded by photoreceptor atrophy. They introduce visual information by electrical stimulation of the surviving inner retinal neurons. Subretinal implants target the graded-response secondary neurons, primarily the bipolar cells, which then transfer the information to the ganglion cells via the retinal neural network. Therefore, many features of natural retinal signal processing can be preserved in this approach if the inner retinal network is retained. Epiretinal implants stimulate primarily the ganglion cells, and hence should encode the visual information in spiking patterns, which, ideally, should match the target cell types. Currently, subretinal arrays are being developed primarily for restoration of central vision in patients impaired by age-related macular degeneration (AMD), while epiretinal implants-for patients blinded by retinitis pigmentosa, where the inner retina is less preserved. This review describes the concepts and technologies, preclinical characterization of prosthetic vision and clinical outcomes, and provides a glimpse into future developments.
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Affiliation(s)
- Daniel Palanker
- Department of Ophthalmology and Hansen Experimental Physics Laboratory, Stanford University, Stanford, California 94305, USA
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3
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Carvalho J, Fernandes FF, Shemesh N. Extensive topographic remapping and functional sharpening in the adult rat visual pathway upon first visual experience. PLoS Biol 2023; 21:e3002229. [PMID: 37590177 PMCID: PMC10434970 DOI: 10.1371/journal.pbio.3002229] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/03/2023] [Indexed: 08/19/2023] Open
Abstract
Understanding the dynamics of stability/plasticity balances during adulthood is pivotal for learning, disease, and recovery from injury. However, the brain-wide topography of sensory remapping remains unknown. Here, using a first-of-its-kind setup for delivering patterned visual stimuli in a rodent magnetic resonance imaging (MRI) scanner, coupled with biologically inspired computational models, we noninvasively mapped brain-wide properties-receptive fields (RFs) and spatial frequency (SF) tuning curves-that were insofar only available from invasive electrophysiology or optical imaging. We then tracked the RF dynamics in the chronic visual deprivation model (VDM) of plasticity and found that light exposure progressively promoted a large-scale topographic remapping in adult rats. Upon light exposure, the initially unspecialized visual pathway progressively evidenced sharpened RFs (smaller and more spatially selective) and enhanced SF tuning curves. Our findings reveal that visual experience following VDM reshapes both structure and function of the visual system and shifts the stability/plasticity balance in adults.
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Affiliation(s)
- Joana Carvalho
- Laboratory of Preclinical MRI, Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Francisca F. Fernandes
- Laboratory of Preclinical MRI, Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Noam Shemesh
- Laboratory of Preclinical MRI, Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
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4
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Johnson NP, Gregorich SM, Passaglia CL. Spatiotemporal Contrast Sensitivity of Brown-Norway Rats under Scotopic and Photopic Illumination. Neuroscience 2020; 449:63-73. [PMID: 33035619 DOI: 10.1016/j.neuroscience.2020.09.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/03/2020] [Accepted: 09/28/2020] [Indexed: 11/24/2022]
Abstract
Rats are a popular animal model for vision research and for investigating disorders of the visual system. The study aimed to quantify the spatiotemporal contrast sensitivity function (CSF) of healthy adult Brown-Norway rats under scotopic and photopic illumination. Animals were trained to jump onto the one of two adjacent platforms behind which was displayed a sinewave grating pattern. Contrast thresholds of light- and dark-adapted rats were determined using a staircase method of adjustment for gratings that varied in spatial frequency (sf) and temporal frequency (tf) and ranged several log-units in mean luminance. Photopic CSFs showed strong bandpass spatial tuning, consistent with prior measurements, and weak bandpass temporal tuning. CSFs were parameterized by a truncated log-parabola model, yielding a peak contrast sensitivity of 52 ± 9, peak sf of 0.17 ± 0.05 cycles/degree, sf limit of 1.6 ± 0.3 cycles/degree, low sf attenuation of 85 ± 9%, peak tf of 1.7 ± 1.1 Hz, extrapolated tf limit of 166 ± 44 Hz, and low tf attenuation of 55 ± 12%. CSFs became more lowpass and decreased systematically in contrast sensitivity and spatiotemporal acuity as mean luminance was reduced. CSFs were also measured via the visual head-tracking reflex. Photopic contrast sensitivity, spatial acuity, and temporal acuity were all markedly below that of the grating detection task and optomotor findings for other rat strains. The CSF data provide a comprehensive and quantitative description of rat spatial and temporal vision and a benchmark for evaluating effects of ocular diseases on their ability to see.
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Affiliation(s)
- Nicholas P Johnson
- University of South Florida, Molecular Pharmacology & Physiology Department, 12901 Bruce B Downs Boulevard MDC 40, Tampa, FL 33612, United States
| | - Sarah M Gregorich
- University of South Florida, Medical Engineering Department, 4202 E Fowler Avenue, Tampa, FL 33620, United States
| | - Christopher L Passaglia
- University of South Florida, Molecular Pharmacology & Physiology Department, 12901 Bruce B Downs Boulevard MDC 40, Tampa, FL 33612, United States; University of South Florida, Medical Engineering Department, 4202 E Fowler Avenue, Tampa, FL 33620, United States; University of South Florida, Ophthalmology Department, 12901 Bruce B Downs Boulevard MDC21, Tampa, FL 33612, United States.
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5
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Gross A, Ivzan NH, Farah N, Mandel Y. High-resolution VSDI retinotopic mapping via a DLP-based projection system. BIOMEDICAL OPTICS EXPRESS 2019; 10:5117-5129. [PMID: 31646034 PMCID: PMC6788600 DOI: 10.1364/boe.10.005117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/14/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
High-resolution recording of visual cortex activity is an important tool for vision research. Using a customized digital mirror device (DMD) - based system equipped with retinal imaging, we projected visual stimuli directly on the rat retina and recorded cortical responses by voltage-sensitive dye imaging. We obtained robust cortical responses and generated high-resolution retinotopic maps at an unprecedented retinal resolution of 4.6 degrees in the field of view, while further distinguishing between normal and pathological retinal areas. This system is a useful tool for studying the cortical response to localized retinal stimulation and may shed light on various cortical plasticity processes.
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Affiliation(s)
- Adi Gross
- Faculty of Life Sciences, School of Optometry and Vision Science, Bar-Ilan University, Ramat Gan, 5290002, Israel
- These authors equally contributed to this research
| | - Nadav H. Ivzan
- Faculty of Life Sciences, School of Optometry and Vision Science, Bar-Ilan University, Ramat Gan, 5290002, Israel
- These authors equally contributed to this research
| | - Nairouz Farah
- Faculty of Life Sciences, School of Optometry and Vision Science, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Yossi Mandel
- Faculty of Life Sciences, School of Optometry and Vision Science, Bar-Ilan University, Ramat Gan, 5290002, Israel
- Bar Ilan’s Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat Gan, 5290002, Israel
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6
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Environmental Anchoring of Head Direction in a Computational Model of Retrosplenial Cortex. J Neurosci 2017; 36:11601-11618. [PMID: 27852770 DOI: 10.1523/jneurosci.0516-16.2016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 07/30/2016] [Accepted: 08/04/2016] [Indexed: 01/29/2023] Open
Abstract
Allocentric (world-centered) spatial codes driven by path integration accumulate error unless reset by environmental sensory inputs that are necessarily egocentric (body-centered). Previous models of the head direction system avoided the necessary transformation between egocentric and allocentric reference frames by placing visual cues at infinity. Here we present a model of head direction coding that copes with exclusively proximal cues by making use of a conjunctive representation of head direction and location in retrosplenial cortex. Egocentric landmark bearing of proximal cues, which changes with location, is mapped onto this retrosplenial representation. The model avoids distortions due to parallax, which occur in simple models when a single proximal cue card is used, and can also accommodate multiple cues, suggesting how it can generalize to arbitrary sensory environments. It provides a functional account of the anatomical distribution of head direction cells along Papez' circuit, of place-by-direction coding in retrosplenial cortex, the anatomical connection from the anterior thalamic nuclei to retrosplenial cortex, and the involvement of retrosplenial cortex in navigation. In addition to parallax correction, the same mechanism allows for continuity of head direction coding between connected environments, and shows how a head direction representation can be stabilized by a single within arena cue. We also make predictions for drift during exploration of a new environment, the effects of hippocampal lesions on retrosplenial cells, and on head direction coding in differently shaped environments. SIGNIFICANCE STATEMENT The activity of head direction cells signals the direction of an animal's head relative to landmarks in the world. Although driven by internal estimates of head movements, head direction cells must be kept aligned to the external world by sensory inputs, which arrive in the reference frame of the sensory receptors. We present a computational model, which proposes that sensory inputs are correctly associated to head directions by virtue of a conjunctive representation of place and head directions in the retrosplenial cortex. The model allows for a stable head direction signal, even when the sensory input from nearby cues changes dramatically whenever the animal moves to a different location, and enables stable representations of head direction across connected environments.
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Kuhrt H, Bringmann A, Härtig W, Wibbelt G, Peichl L, Reichenbach A. The Retina of Asian and African Elephants: Comparison of Newborn and Adult. BRAIN, BEHAVIOR AND EVOLUTION 2017; 89:84-103. [PMID: 28437785 DOI: 10.1159/000464097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 02/14/2017] [Indexed: 11/19/2022]
Abstract
Elephants are precocial mammals that are relatively mature as newborns and mobile shortly after birth. To determine whether the retina of newborn elephants is capable of supporting the mobility of elephant calves, we compared the retinal structures of 2 newborn elephants (1 African and 1 Asian) and 2 adult animals of both species by immunohistochemical and morphometric methods. For the first time, we present here a comprehensive qualitative and quantitative characterization of the cellular composition of the newborn and the adult retinas of 2 elephant species. We found that the retina of elephants is relatively mature at birth. All retinal layers were well discernible, and various retinal cell types were detected in the newborns, including Müller glial cells (expressing glutamine synthetase and cellular retinal binding protein; CRALBP), cone photoreceptors (expressing S-opsin or M/L-opsin), protein kinase Cα-expressing bipolar cells, tyrosine hydroxylase-, choline acetyltransferase (ChAT)-, calbindin-, and calretinin-expressing amacrine cells, and calbindin-expressing horizontal cells. The retina of newborn elephants contains discrete horizontal cells which coexpress ChAT, calbindin, and calretinin. While the overall structure of the retina is very similar between newborn and adult elephants, various parameters change after birth. The postnatal thickening of the retinal ganglion cell axons and the increase in ganglion cell soma size are explained by the increase in body size after birth, and the decreases in the densities of neuronal and glial cells are explained by the postnatal expansion of the retinal surface area. The expression of glutamine synthetase and CRALBP in the Müller cells of newborn elephants suggests that the cells are already capable of supporting the activities of photoreceptors and neurons. As a peculiarity, the elephant retina contains both normally located and displaced giant ganglion cells, with single cells reaching a diameter of more than 50 µm in adults and therefore being almost in the range of giant retinal ganglion cells found in aquatic mammals. Some of these ganglion cells are displaced into the inner nuclear layer, a unique feature of terrestrial mammals. For the first time, we describe here the occurrence of many bistratified rod bipolar cells in the elephant retina. These bistratified bipolar cells may improve nocturnal contrast perception in elephants given their arrhythmic lifestyle.
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Affiliation(s)
- Heidrun Kuhrt
- Paul Flechsig Institute of Brain Research, University of Leipzig Medical Faculty, Leipzig, Germany
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Goetz GA, Palanker DV. Electronic approaches to restoration of sight. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:096701. [PMID: 27502748 PMCID: PMC5031080 DOI: 10.1088/0034-4885/79/9/096701] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Retinal prostheses are a promising means for restoring sight to patients blinded by the gradual atrophy of photoreceptors due to retinal degeneration. They are designed to reintroduce information into the visual system by electrically stimulating surviving neurons in the retina. This review outlines the concepts and technologies behind two major approaches to retinal prosthetics: epiretinal and subretinal. We describe how the visual system responds to electrical stimulation. We highlight major differences between direct encoding of the retinal output with epiretinal stimulation, and network-mediated response with subretinal stimulation. We summarize results of pre-clinical evaluation of prosthetic visual functions in- and ex vivo, as well as the outcomes of current clinical trials of various retinal implants. We also briefly review alternative, non-electronic, approaches to restoration of sight to the blind, and conclude by suggesting some perspectives for future advancement in the field.
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Affiliation(s)
- G A Goetz
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305, USA. Neurosurgery, Stanford University, Stanford, CA 94305, USA
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9
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Comparison of visual receptive field properties of the superior colliculus and primary visual cortex in rats. Brain Res Bull 2015. [DOI: 10.1016/j.brainresbull.2015.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Lorach H, Goetz G, Smith R, Lei X, Mandel Y, Kamins T, Mathieson K, Huie P, Harris J, Sher A, Palanker D. Photovoltaic restoration of sight with high visual acuity. Nat Med 2015; 21:476-82. [PMID: 25915832 PMCID: PMC4601644 DOI: 10.1038/nm.3851] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 03/27/2015] [Indexed: 12/11/2022]
Abstract
Patients with retinal degeneration lose sight due to the gradual demise of photoreceptors. Electrical stimulation of surviving retinal neurons provides an alternative route for the delivery of visual information. We demonstrate that subretinal implants with 70-μm-wide photovoltaic pixels provide highly localized stimulation of retinal neurons in rats. The electrical receptive fields recorded in retinal ganglion cells were similar in size to the natural visual receptive fields. Similarly to normal vision, the retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images and nonlinear spatial summation. In rats with retinal degeneration, these photovoltaic arrays elicited retinal responses with a spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in healthy rats. The ease of implantation of these wireless and modular arrays, combined with their high resolution, opens the door to the functional restoration of sight in patients blinded by retinal degeneration.
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Affiliation(s)
- Henri Lorach
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
- Department of Ophthalmology, Stanford University, Stanford, CA, USA
- Inserm UMR_S968, Institut de la Vision, Paris, France
| | - Georges Goetz
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Richard Smith
- Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Xin Lei
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Yossi Mandel
- The Mina & Everard Goodman Faculty of Life Sciences, Bar Ilan University, Israel
| | - Theodore Kamins
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Keith Mathieson
- Institute of Photonics, University of Strathclyde, Glasgow, UK
| | - Philip Huie
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
- Department of Ophthalmology, Stanford University, Stanford, CA, USA
| | - James Harris
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Alexander Sher
- Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel Palanker
- Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA, USA
- Department of Ophthalmology, Stanford University, Stanford, CA, USA
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11
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Zoccolan D. Invariant visual object recognition and shape processing in rats. Behav Brain Res 2015; 285:10-33. [PMID: 25561421 PMCID: PMC4383365 DOI: 10.1016/j.bbr.2014.12.053] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 12/19/2014] [Accepted: 12/25/2014] [Indexed: 12/28/2022]
Abstract
Invariant visual object recognition is the ability to recognize visual objects despite the vastly different images that each object can project onto the retina during natural vision, depending on its position and size within the visual field, its orientation relative to the viewer, etc. Achieving invariant recognition represents such a formidable computational challenge that is often assumed to be a unique hallmark of primate vision. Historically, this has limited the invasive investigation of its neuronal underpinnings to monkey studies, in spite of the narrow range of experimental approaches that these animal models allow. Meanwhile, rodents have been largely neglected as models of object vision, because of the widespread belief that they are incapable of advanced visual processing. However, the powerful array of experimental tools that have been developed to dissect neuronal circuits in rodents has made these species very attractive to vision scientists too, promoting a new tide of studies that have started to systematically explore visual functions in rats and mice. Rats, in particular, have been the subjects of several behavioral studies, aimed at assessing how advanced object recognition and shape processing is in this species. Here, I review these recent investigations, as well as earlier studies of rat pattern vision, to provide an historical overview and a critical summary of the status of the knowledge about rat object vision. The picture emerging from this survey is very encouraging with regard to the possibility of using rats as complementary models to monkeys in the study of higher-level vision.
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Affiliation(s)
- Davide Zoccolan
- Visual Neuroscience Lab, International School for Advanced Studies (SISSA), 34136 Trieste, Italy.
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12
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Kurylo DD, Chung C, Yeturo S, Lanza J, Gorskaya A, Bukhari F. Effects of contrast, spatial frequency, and stimulus duration on reaction time in rats. Vision Res 2014; 106:20-6. [PMID: 25451244 DOI: 10.1016/j.visres.2014.10.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/03/2014] [Accepted: 10/08/2014] [Indexed: 10/24/2022]
Abstract
Early visual processing in rats is mediated by several pre-cortical pathways as well as multiple retinal ganglion cell types that vary in response characteristics. Discrete processing is thereby optimized for select ranges of stimulus parameters. In order to explore variation in response characteristics at a perceptual level, visual detection in rats was measured across a range of contrasts, spatial frequencies, and durations. Rats responded to the onset of Gabor patches. Onset time occurred after a random delay, and reaction time (RT) frequency distribution served to index target visibility. It was found that lower spatial frequency produced shorter RTs, as well as increased RT equivalent of contrast gain. Brief stimulus presentation reduced target visibility, slowed RTs, and reduced contrast gain at higher spatial frequencies. However, brief stimuli shortened RTs at low contrasts and low spatial frequencies, suggesting transient stimuli are more efficiently processed under these conditions. Collectively, perceptual characteristics appear to reflect distinctions in neural responses at early stages of processing. The RT characteristics found here may thereby reflect the contribution of multiple channels, and suggest a progressive shift in relative involvement across parameter levels.
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Affiliation(s)
- Daniel D Kurylo
- Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States.
| | - Caroline Chung
- Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States
| | - Sowmya Yeturo
- Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States
| | - Joseph Lanza
- Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States
| | - Arina Gorskaya
- Department of Psychology, Brooklyn College CUNY, Brooklyn, NY 11210, United States
| | - Farhan Bukhari
- Department of Computer Science, The Graduate Center CUNY, New York, NY 10016, United States
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13
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Meier PM, Reinagel P. Rats and humans differ in processing collinear visual features. Front Neural Circuits 2013; 7:197. [PMID: 24379758 PMCID: PMC3862114 DOI: 10.3389/fncir.2013.00197] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 11/28/2013] [Indexed: 11/27/2022] Open
Abstract
Behavioral studies in humans and rats demonstrate that visual detection of a target stimulus is sensitive to surrounding spatial patterns. In both species, the detection of an oriented visual target is affected when the surrounding region contains flanking stimuli that are collinear to the target. In many studies, collinear flankers have been shown to improve performance in humans, both absolutely (compared to performance with no flankers) and relative to non-collinear flankers. More recently, collinear flankers have been shown to impair performance in rats both absolutely and relative to non-collinear flankers. However, these observations spanned different experimental paradigms. Past studies in humans have shown that the magnitude and even sign of flanker effects can depend critically on the details of stimulus and task design. Therefore either task differences or species could explain the opposite findings. Here we provide a direct comparison of behavioral data between species and show that these differences persist – collinear flankers improve performance in humans, and impair performance in rats – in spite of controls that match stimuli, experimental paradigm, and learning procedure. There is evidence that the contrasts of the target and the flankers could affect whether surround processing is suppressive or facilitatory. In a second experiment, we explored a range of contrast conditions in the rat, to determine if contrast could explain the lack of collinear facilitation. Using different pairs of target and flanker contrast, the rat’s collinear impairment was confirmed to be robust across a range of contrast conditions. We conclude that processing of collinear features is indeed different between rats and humans. We speculate that the observed difference between rat and human is caused by the combined impact of differences in the statistics in natural retinal images, the representational capacity of neurons in visual cortex, and attention.
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Affiliation(s)
- Philip M Meier
- Department of Neurosciences, Division of Medicine, University of California at San Diego La Jolla, CA, USA
| | - Pamela Reinagel
- Section of Neurobiology, Division of Biology, University of California at San Diego La Jolla, CA, USA
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14
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Andermann ML, Kerlin AM, Roumis DK, Glickfeld LL, Reid RC. Functional specialization of mouse higher visual cortical areas. Neuron 2012; 72:1025-39. [PMID: 22196337 DOI: 10.1016/j.neuron.2011.11.013] [Citation(s) in RCA: 288] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2011] [Indexed: 10/14/2022]
Abstract
The mouse is emerging as an important model for understanding how sensory neocortex extracts cues to guide behavior, yet little is known about how these cues are processed beyond primary cortical areas. Here, we used two-photon calcium imaging in awake mice to compare visual responses in primary visual cortex (V1) and in two downstream target areas, AL and PM. Neighboring V1 neurons had diverse stimulus preferences spanning five octaves in spatial and temporal frequency. By contrast, AL and PM neurons responded best to distinct ranges of stimulus parameters. Most strikingly, AL neurons preferred fast-moving stimuli while PM neurons preferred slow-moving stimuli. By contrast, neurons in V1, AL, and PM demonstrated similar selectivity for stimulus orientation but not for stimulus direction. Based on these findings, we predict that area AL helps guide behaviors involving fast-moving stimuli (e.g., optic flow), while area PM helps guide behaviors involving slow-moving objects.
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Affiliation(s)
- Mark L Andermann
- Department of Neurobiology, Harvard Medical School, Goldenson 243, 220 Longwood Avenue, Boston, MA 02115, USA
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15
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Wang Q, Gao E, Burkhalter A. Gateways of ventral and dorsal streams in mouse visual cortex. J Neurosci 2011; 31:1905-18. [PMID: 21289200 PMCID: PMC3040111 DOI: 10.1523/jneurosci.3488-10.2011] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 11/17/2010] [Accepted: 12/03/2010] [Indexed: 11/21/2022] Open
Abstract
It is widely held that the spatial processing functions underlying rodent navigation are similar to those encoding human episodic memory (Doeller et al., 2010). Spatial and nonspatial information are provided by all senses including vision. It has been suggested that visual inputs are fed to the navigational network in cortex and hippocampus through dorsal and ventral intracortical streams (Whitlock et al., 2008), but this has not been shown directly in rodents. We have used cytoarchitectonic and chemoarchitectonic markers, topographic mapping of receptive fields, and pathway tracing to determine in mouse visual cortex whether the lateromedial field (LM) and the anterolateral field (AL), which are the principal targets of primary visual cortex (V1) (Wang and Burkhalter, 2007) specialized for processing nonspatial and spatial visual information (Gao et al., 2006), are distinct areas with diverse connections. We have found that the LM/AL border coincides with a change in type 2 muscarinic acetylcholine receptor expression in layer 4 and with the representation of the lower visual field periphery. Our quantitative analyses also show that LM strongly projects to temporal cortex as well as the lateral entorhinal cortex, which has weak spatial selectivity (Hargreaves et al., 2005). In contrast, AL has stronger connections with posterior parietal cortex, motor cortex, and the spatially selective medial entorhinal cortex (Haftig et al., 2005). These results support the notion that LM and AL are architecturally, topographically, and connectionally distinct areas of extrastriate visual cortex and that they are gateways for ventral and dorsal streams.
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Affiliation(s)
- Quanxin Wang
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Enquan Gao
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Andreas Burkhalter
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
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Retinal ganglion cell density of the black rhinoceros (Diceros bicornis): Calculating visual resolution. Vis Neurosci 2008; 25:215-20. [DOI: 10.1017/s0952523808080498] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractA single right retina from a black rhinoceros was whole mounted, stained and analyzed to determine the visual resolution of the rhinoceros, an animal with reputedly poor eyesight. A range of small (15-μm diameter) to large (100-μm diameter) ganglion cell types was seen across the retina. We observed two regions of high density of retinal ganglion cells at either end of a long, but thin, horizontal streak. The temporal specialization, which receives light from the anterior visual field, exhibited a ganglion cell density of approximately 2000/mm2, while the nasal specialization exhibited a density of approximately 1500/mm2. The retina exhibited a ganglion cell density bias toward the upper half, especially so, the upper temporal quadrant, indicating that the rhinoceros would be processing visual information from the visual field below the anterior horizon for the most part. Our calculations indicate that the rhinoceros has a visual resolution of 6 cycles/degree. While this resolution is one-tenth that of humans (60 cycles/deg) and less than that of the domestic cat (9 cycles/deg), it is comparable to that of the rabbit (6 cycles/deg), and exceeds that seen in a variety of other mammals including seals, dolphins, microbats, and rats. Thus, the reputation of the rhinoceros as a myopic, weakly visual animal is not supported by our observations of the retina. We calculate that the black rhinoceros could readily distinguish a 30 cm wide human at a distance of around 200 m given the appropriate visual background.
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Girman SV, Lund RD. Most superficial sublamina of rat superior colliculus: neuronal response properties and correlates with perceptual figure-ground segregation. J Neurophysiol 2007; 98:161-77. [PMID: 17475720 DOI: 10.1152/jn.00059.2007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The uppermost layer (stratum griseum superficiale, SGS) of the superior colliculus (SC) provides an important gateway from the retina to the visual extrastriate and visuomotor systems. The majority of attention has been given to the role of this "visual" SC in saccade generation and target selection and it is generally considered to be less important in visual perception. We have found, however, that in the rat SGS1, the most superficial division of the SGS, the neurons perform very sophisticated analysis of visual information. First, in studying their responses with a variety of flashing stimuli we found that the neurons respond not to brightness changes per se, but to the appearance and/or disappearance of visual shapes in their receptive fields (RFs). Contrary to conventional RFs of neurons at the early stages of visual processing, the RFs in SGS1 cannot be described in terms of fixed spatial distribution of excitatory and inhibitory inputs. Second, SGS1 neurons showed robust orientation tuning to drifting gratings and orientation-specific modulation of the center response from surround. These are features previously seen only in visual cortical neurons and are considered to be involved in "contour" perception and figure-ground segregation. Third, responses of SGS1 neurons showed complex dynamics; typically the response tuning became progressively sharpened with repetitive grating periods. We conclude that SGS1 neurons are involved in considerably more complex analysis of retinal input than was previously thought. SGS1 may participate in early stages of figure-ground segregation and have a role in low-resolution nonconscious vision as encountered after visual decortication.
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Affiliation(s)
- S V Girman
- University of Utah, Salt Lake City, UT, USA.
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Prévost F, Lepore F, Guillemot JP. Spatio-temporal receptive field properties of cells in the rat superior colliculus. Brain Res 2007; 1142:80-91. [PMID: 17303094 DOI: 10.1016/j.brainres.2007.01.041] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 01/11/2007] [Accepted: 01/14/2007] [Indexed: 10/23/2022]
Abstract
Although the rat is widely used in neurobehavioural research, the spatio-temporal receptive field properties of neurons in superficial layers of the superior colliculus are relatively unknown. Extracellular recordings were carried out in anesthetized Long Evans rats. Neurons in these layers had simple-like and complex-like receptive fields (RFs). Most cells (67%) had RFs showing band-pass and low-pass spatial frequency (SF) tuning profiles. Spatial band-pass profiles showed low optimal SF (mean=0.03 c/deg), low spatial resolution (mean=0.18 c/deg) and large spatial bandwidths (mean=2.3 octaves). More than two-thirds of the RFs (71%) were selective to orientation and only 11% were clearly direction selective. Nearly two-thirds of cells (68%) had band-pass temporal frequency (TF) tuning profiles with narrow bandwidths (mean=1.7 oct.) whereas the others showed low-pass TF tuning profiles. Temporal band-pass profiles had low optimal TFs (mean=3.5 c/s). Although some cells showed relatively low contrast thresholds (6%), most cells only responded to high contrast values (mean=38.2%). These results show that the spatial resolution of collicular cells is poor and that they respond mainly to highly contrasted moving stimuli.
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Affiliation(s)
- François Prévost
- Centre de Recherche en Neuropsychologie et Cognition, Département de Psychologie, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, Canada H3C 3J7
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Iny K, Heynen AJ, Sklar E, Bear MF. Bidirectional modifications of visual acuity induced by monocular deprivation in juvenile and adult rats. J Neurosci 2006; 26:7368-74. [PMID: 16837583 PMCID: PMC6674195 DOI: 10.1523/jneurosci.0124-06.2006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recent electrophysiological studies of rodent visual cortex suggest that, in addition to deprived-eye depression, monocular deprivation (MD) also shifts ocular dominance by potentiation of open-eye responses. We used computer-based, two-choice discrimination tasks to assess the behavioral significance of these findings in rats. As expected, prolonged MD, from postnatal day 21 until adulthood (>150 d) markedly decreased visual acuity through the deprived eye. However, we also found that the acuity through the nondeprived eye was significantly enhanced compared with normally reared controls. Interestingly, when the deprived eye was opened in adults, there was a gradual but incomplete recovery of acuity in the deprived eye preceded by a loss of the enhanced acuity in the nondeprived eye. These changes were reversed by again reclosing the eye. These findings suggest that the bidirectional changes in visually evoked responses after MD are behaviorally meaningful and that significant plasticity is exhibited well into adulthood.
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Nuñez JL, Huppenbauer CB, McAbee MD, Juraska JM, DonCarlos LL. Androgen receptor expression in the developing male and female rat visual and prefrontal cortex. JOURNAL OF NEUROBIOLOGY 2003; 56:293-302. [PMID: 12884268 DOI: 10.1002/neu.10236] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Gonadal steroid hormones are known to influence the development of the cerebral cortex of mammals. Steroid hormone action involves hormone binding to cytoplasmic or nuclear receptors, followed by DNA binding and gene transcription. The goals of the present study were twofold: to determine whether androgen receptors are present during development in two known androgen sensitive regions of the rat cerebral cortex, the primary visual cortex (Oc1) and the anterior cingulate/frontal cortex (Cg1/Fr2); and to determine whether androgen receptor (AR) expression in these regions differs between developing males and females. We used immunocytochemistry to detect AR protein on postnatal days 0, 4, and 10, and in situ hybridization to detect AR mRNA on postnatal day 10 in male and female rats. The level of AR expression was specific to the cortical region, with higher AR immunoreactive cell density and more AR mRNA in Oc1 than in Cg1/Fr2. AR immunoreactive cell density increased with age in both regions. Finally, on postnatal day 10, males had a higher AR immunoreactive cell density and more AR mRNA in Oc1 than did females. Thus, the presence of ARs may allow androgens to directly influence the development the cerebral cortex.
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Affiliation(s)
- J L Nuñez
- Neuroscience Program and Department of Psychology, University of Illinois, Champaign, Illinois 61820, USA
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Paz-Villagràn V, Lenck-Santini PP, Save E, Poucet B. Properties of place cell firing after damage to the visual cortex. Eur J Neurosci 2002; 16:771-6. [PMID: 12270054 DOI: 10.1046/j.1460-9568.2002.02154.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hippocampal place cells were recorded while rats with lesions of the striate visual cortex foraged for food pellets in a cylindrical arena. Compared to control rats, rats with striate damage had place cells whose firing was less well organized in space, according to a measurement of spatial coherence. More importantly, the spatial location of firing fields in rats with striate lesions was poorly controlled by three-dimensional objects, unlike the fields of either normal sighted rats or early blind rats. These findings suggest a possible contribution of the striate visual cortex to the selection of cues used for anchoring place cell firing fields in space.
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Affiliation(s)
- Vietminh Paz-Villagràn
- Laboratory of Neurobiology and Cognition, CNRS, 31 chemin Joseph-Aiguier, 13402 Marseille cedex 20, France
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Prusky GT, Harker KT, Douglas RM, Whishaw IQ. Variation in visual acuity within pigmented, and between pigmented and albino rat strains. Behav Brain Res 2002; 136:339-48. [PMID: 12429395 DOI: 10.1016/s0166-4328(02)00126-2] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many researchers assume that laboratory rats have poor vision, and accordingly, that they need not consider differences in the visual function of rats as a consequence of strain or experience. Currently, it is not specifically known whether rat domestication has negatively affected the visual function of laboratory rat strains, what the effects of strain albinism are on rat visual function, or whether there are strain differences in the visual function of laboratory rats that are independent of pigmentation. In order to address these questions, we measured psychophysically the vertical grating acuity of three pigmented (Dark Agouti, Fisher-Norway, Long-Evans) and three albino (Fisher-344, Sprague-Dawley, Wistar) strains of laboratory rats, and compared their acuity with that of wild rats. The grating thresholds of Dark Agouti, Long-Evans and wild strains clustered around 1.0 cycle/degree (c/d) and did not significantly differ from one another. Fisher-Norway rats, however, had a significantly higher threshold of 1.5 c/d. The grating thresholds of Fisher-344, Sprague-Dawley, and Wistar strains, which were clustered around 0.5 c/d, were significantly lower than those of the pigmented strains. These data demonstrate that there is significant strain variability in the visual function of laboratory rats. Domestication of Long-Evans and Dark Agouti strains does not appear to have compromised visual acuity, but in the case of Fisher-Norway rats, selective breeding may have enhanced their acuity. Strain selection associated with albinism, however, appears to have consistently impaired visual acuity. Therefore, a consideration of strain differences in visual function should accompany the selection of a rat model for behavioral tasks that involve vision, or when comparing visuo-behavioral measurements across rat strains.
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Affiliation(s)
- Glen T Prusky
- Department of Psychology and Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4.
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Boire D, Théoret H, Ptito M. Visual pathways following cerebral hemispherectomy. PROGRESS IN BRAIN RESEARCH 2002; 134:379-97. [PMID: 11702556 DOI: 10.1016/s0079-6123(01)34025-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The anatomical consequences of unilateral cerebral hemispherectomy in some animal models are reviewed. We have shown that the retinogenigulate pathway undergoes severe degenerative changes in hemispherectomized monkeys, greater than those shown in cats and we proposed that remaining retinal terminals to the dorsal lateral geniculate nucleus have little potential for conveying visual information any further. All subdivisions of the pulvinar undergo severe degeneration following hemispherectomy showing that the ascending tectofugal pathway is also shut off. On the other hand, the retina subserving the blind field is not depleted of ganglion cells which still send normal appearing terminals to the midbrain pretectum and superior colliculus. Visual information from the blind hemifield can thus gain access to the brain and could potentially reach the contralateral cerebral cortex through the midbrain commissure and possibly through thalamic commissural cells.
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Affiliation(s)
- D Boire
- Ecole d'Optométrie, Université de Montréal, CP, 6128, succursale Centre-ville, Montréal, PQ, H3C 3J7 Canada
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Coffey PJ, Whiteley SJ, Lund RD. Preservation and restoration of vision following transplantation. PROGRESS IN BRAIN RESEARCH 2001; 127:489-99. [PMID: 11142043 DOI: 10.1016/s0079-6123(00)27024-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- P J Coffey
- Visual Transplantation Research Group, Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TP, UK.
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Abstract
Rats have become a popular model for investigating the mechanisms underlying ocular dominance plasticity; however, no quantitative assessment of the effects of visual deprivation on behavioural acuity has been reported in this species. We measured the spatial acuity of monocularly and binocularly deprived rats with a visual discrimination task. The average spatial acuity of normal rats and rats deprived of vision after postnatal day 40 was approximately 1 cycle/degree. Monocular deprivation up to postnatal day 40 resulted in a 30% decrease in acuity and there was no recovery after 8 months. Identical binocular deprivation produced a comparable but significantly smaller reduction in acuity. The deleterious effects of monocular and binocular deprivation on visual acuity indicate that the development of cortical receptive field properties related to spatial tuning are affected by both monocular and binocular deprivation. The similarities in the effects of visual deprivation on visual acuity between rats and other mammals confirm that rats are a good model system for studying the cellular and molecular mechanisms underlying experience-dependent visual plasticity.
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Affiliation(s)
- G T Prusky
- Department of Psychology and Neuroscience, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada.
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26
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Abstract
We have developed a simple computer-based discrimination task that enables the quick determination of visual acuities in rodents. A grating is displayed randomly on one of two monitors at the wide end of a trapezoidal-shaped tank containing shallow water. Animals are trained to swim toward the screens, and at a fixed distance, choose the screen displaying the grating and escape to a submerged platform hidden below it. Both mice and rats learn the task quickly. Performance falls below 70% when the spatial frequency is increased beyond 0.5 cycles in most C57BU6 mice, and around 1.0 cycles per degree (cpd) in Long-Evans rats.
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Affiliation(s)
- G T Prusky
- Department of Psychology and Neuroscience, The University of Lethbridge, 4401 University Drive, AB, TIK 3M4, Lethbridge, Canada.
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Keller J, Strasburger H, Cerutti DT, Sabel BA. Assessing spatial vision - automated measurement of the contrast-sensitivity function in the hooded rat. J Neurosci Methods 2000; 97:103-10. [PMID: 10788664 DOI: 10.1016/s0165-0270(00)00173-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The contrast-sensitivity function (CSF) provides a concise and thorough description of an organism's spatial vision; it is widely used to describe vision in animals and humans, to track developmental changes in vision, and to compare vision among different species. Despite the predominance of rats in neuroscience research, their vision is not thoroughly studied due to the complexity of psychophysical measurement and a generally held notion that rat vision is poor. We therefore designed an economical and rapid method to assess the hooded rat's CSF, using a computer monitor to display stimuli and an infrared touch screen to record responses. A six-alternative forced-choice task presented trials in which a sine-wave grating (S+), varying in spatial frequency and contrast, was displayed at different locations along with five gray stimuli (S-). Nose pokes to the S+ but not the S- produced water reinforcers. Contrasts were tested at each spatial frequency with a simple adaptive procedure until stimulus detection fell below chance. Psychometric functions were obtained by maximum-likelihood fitting of a logistic function to the raw data, obtaining the threshold as the function's point of inflection. As in previous studies with rats, CSFs showed an inverse-U shape with peak sensitivity at 0.12 cyc/deg and acuity just under 1 cyc/deg. The results indicate the present computer-controlled behavioral testing device is a precise and efficient instrument to assess spatial visual function in rats.
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Affiliation(s)
- J Keller
- Institute of Medical Psychology, Otto-von-Guericke University of Magdeburg, Leipziger Strasse 44, D-39120, Magdeburg, Germany
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Girman SV, Sauvé Y, Lund RD. Receptive field properties of single neurons in rat primary visual cortex. J Neurophysiol 1999; 82:301-11. [PMID: 10400959 DOI: 10.1152/jn.1999.82.1.301] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The rat is used widely to study various aspects of vision including developmental events and numerous pathologies, but surprisingly little is known about the functional properties of single neurons in the rat primary visual cortex (V1). These were investigated in the anesthetized (Hypnorm-Hypnovel), paralyzed animal by presenting gratings of different orientations, spatial and temporal frequencies, dimensions, and contrasts. Stimulus presentation and data collection were automated. Most neurons (190/205) showed sharply tuned (</=30 degrees bandwidth at half height) orientation selectivity with a bias for horizontal stimuli (31%). Analysis of response modulation of oriented cells showed a bimodal distribution consistent with the distinction between simple and complex cell types. Orientation specific interactions occurred between the center and the periphery of receptive fields, usually resulting in strong inhibition to center stimulation when both stimuli had the same orientation. There was no evidence for orientation columns nor for orderly change in optimal orientation with tangential tracks through V1. Responses were elicited by spatial frequencies ranging from zero (no grating) to 1.2 cycle/degree (c/ degrees ), peaking at 0.1 c/ degrees, and with a modal cutoff of 0.6 c/ degrees. Half of the neurons responded optimally to drifting gratings rather than flashing uniform field stimuli. Directional preference was seen for 59% of oriented units at all depths in the cortex. Optimal stimuli velocities varied from 10 to 250 degrees /s. Some units, mainly confined to layer 4, responded to velocities as high as 700 degrees /s. Response versus contrast curves (best fit with Naka-Rushton) varied from nearly linear to extremely steep (mean contrast semisaturation 50% and threshold 6%). There was a trend for cells from superficial layers to be more selective to different stimulus parameters than deeper layers cells. We conclude that neurons in rat V1 have complex and diverse visual properties, necessary for precise visual form perception with low spatial resolution.
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Affiliation(s)
- S V Girman
- Institute of Developmental Biology, Russian Academy of Science, Moscow 117808, Russia
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Yagi F, Sakai M, Ikeda Y. Effects of monocular enucleation at birth upon learning of a vertical-horizontal discrimination in hooded rats. Behav Brain Res 1995; 70:181-90. [PMID: 8561908 DOI: 10.1016/0166-4328(95)80007-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Previously we have demonstrated that adult albino rats with one eye removed at birth (OEB) relearn a black-white discrimination faster than those monocularly enucleated at maturity (OET) when relearning is conducted after lesioning of the visual cortex contralateral to the remaining eye (Type A experiment). This faster relearning phenomenon is considered to be one behavioral expression of the functioning of the expanded uncrossed visual pathways (expanded UXVPs) resulting from monocular enucleation at birth. However, neither OEBs nor OETs were able to master the discrimination when the experiment was conducted without previous learning following the same surgical treatment (Type B experiment). We hypothesized that this occurs because the cues to discriminate might be close to the threshold of discrimination for either the normal UXVPs or the expanded UXVPs. In order to gain insight into the hypothesis, the present study was undertaken using hooded rats as subjects which genetically possess larger and presumably more efficient functioning UXVPs. The questions addressed were as follows: 1) Whether or not the UXVPs can mediate a vertical-horizontal discrimination in OEBs and OETs. 2) If they can, is there any difference in the upper limit of discrimination capacity between the normal UXVPs and the expanded UXVPs? Three experiments were carried out. In the Type A experiment OEBs relearned discrimination of the 10-mm stripes [0.44 cycles/degree (c/d)] faster than OETs (Experiment 1), yet in the Type B experiment neither OEBs nor OETs were capable of acquiring that discrimination (Experiment 2). However, they could originally master the discrimination equally well when the width of stripes was broadened to 30 mm (0.15 c/d). And when the width of stripes was systematically reduced thereafter, the width of the smallest stripes for the expanded UXVPs to discriminate was found to be 6 mm (0.73 c/d) and that for the normal UXVPs 10 mm (0.44 c/d) [Experiment 3]. These findings were discussed in relation to the hypothesis advanced on our previous data in albino rats.
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Affiliation(s)
- F Yagi
- Neuropsychology Laboratory, Kochi Medical School, Japan
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Lomber SG, Payne BR, Cornwell P, Pearson HE. Capacity of the retinogeniculate pathway to reorganize following ablation of visual cortical areas in developing and mature cats. J Comp Neurol 1993; 338:432-57. [PMID: 8113448 DOI: 10.1002/cne.903380308] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The purpose of the present study was to determine the pattern and density of retinal projections to the dorsal lateral geniculate nucleus (dLGN) following ablation of visual cortical areas in developing cats of different postnatal ages and in mature cats. The terminations of retinal projections to the dLGN were evaluated following the injection of tritiated amino acids into one eye. Regardless of age, a visual cortical ablation of areas 17 and 18 induces massive death of neurons within the regions of the dLGN that are linked topographically to the cortical areas removed. However, the pattern of retinal projections to these degenerated regions of the dLGN differs depending upon whether the cortical lesion is incurred early in postnatal life or in adulthood. Following ablation on the day of birth (P1), virtually all surviving cells were found in the C-complex of dLGN with only a token number in the A-laminae. Correspondingly, retinal projections were maintained to the C-complex of the nucleus and were barely detectable in the degenerated A-laminae. However, in cats in which areas 17 and 18 had been removed in adulthood (> or = 6 months of age) retinal projections were maintained to the A-laminae even though nearly all neurons in those laminae had degenerated. Moreover, a subgroup of animals that incurred area 17 and 18 ablations at P1 showed that the modification of retinal projections to the A-laminae occurs within the first postnatal month, and an additional subgroup showed that retinal projections become increasingly resistant to the degenerative events in the dLGN that follow ablation of areas 17 and 18 at progressively older ages during the first postnatal month. Furthermore, retinal inputs also respond, in an age-dependent way, to degeneration of neurons in the C-complex induced by extension of the cortical ablation to include extrastriate visual areas.
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Affiliation(s)
- S G Lomber
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Massachusetts 02118
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31
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Ellard CG, Chapman DG. The effects of posterior cortical lesions on responses to visual threats in the Mongolian gerbil (Meriones unguiculatus). Behav Brain Res 1991; 44:163-7. [PMID: 1751007 DOI: 10.1016/s0166-4328(05)80021-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Mongolian gerbils received aspiration lesions of either primary visual cortex (PVC), medial extrastriate visual cortex, retrosplenial cortex (RSC), or sham operations. The responses of gerbils to the presentation of an overhead visual stimulus were recorded in an open field. In all groups, presentation of the stimulus produced an increase in rearing. This suggests that the stimulus was detected by all animals. Gerbils with RSC or PVC lesions showed reduced levels of response to the stimulus. We suggest that some of the observed deficits can be explained as failures to produce responses to threat that are appropriate to the context in which the the threat was presented.
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Affiliation(s)
- C G Ellard
- Department of Psychology, Mount Allison University, Sackville, New Brunswick, Canada
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32
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Sakai M, Ikeda Y, Yagi F. Differential effects of unilateral optic tract transections and visual cortical lesions upon a pattern discrimination in albino rats with removal of one eye at birth. Physiol Behav 1991; 50:409-16. [PMID: 1745687 DOI: 10.1016/0031-9384(91)90087-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previously we have demonstrated that adult rats with one eye removed at birth (OEB) relearn a black-white discrimination faster than control rats monocularly enucleated at maturity (OET), when relearning is conducted after lesions of the visual cortex contralateral to the remaining eye. This faster relearning phenomenon is considered to be one behavioral expression of the functioning of the expanded uncrossed visual pathways resulting from monocular at birth. The present study was concerned with the question of whether the same phenomenon can be observed in the discrimination between alternating black and white stripes oriented horizontally and vertically. Two experiments were carried out. In the first experiment, which is a replication of one of our previous studies, relearning was conducted after the visual cortical lesions contralateral to the remaining eye. The results were consistent with those of the previous one in which neither OEBs nor OETs were found able to relearn the discrimination. In the second experiment, relearning was conducted after transections of the optic tract contralateral to the remaining eye. It was shown that under this condition both OEBs and OETs could relearn the discrimination, and furthermore, that OEBs restored the habit faster than OETs. Possible mechanisms underlying the difference in the results from the two experiments were discussed.
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Affiliation(s)
- M Sakai
- Neuropsychology Laboratory, Saga Medical School, Japan
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Haun F, Cunningham TJ, Rothblat LA. Neurotrophic and behavioral effects of occipital cortex transplants in newborn rats. Vis Neurosci 1989; 2:189-98. [PMID: 2562147 DOI: 10.1017/s0952523800012049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cell suspensions of embryonic occipital cortex were transplanted into newborn rats with large unilateral visual cortex lesions. When the animals were adults, they were tested on a difficult visual discrimination, and subsequently their brains were analyzed for possible neurotrophic effects of the transplants on nonvisual cortical areas which normally form connections with the occipital cortex. Behaviorally, animals with lesions and transplants learn to discriminate between columns and rows of squares at a rate which is identical to normal rats while animals with lesions and no transplants are impaired. Volume and cell-density measures show that the transplants also rescue neurons in cortical area 8 that would normally degenerate following the cortical lesion. No such neurotrophic effect of the transplants is found in cortical area 24 or area 17 contralateral to the lesion. In rats with lesions and no transplants, there is a significant correlation between the amount of area 8 remaining after the lesion and trials to criterion on the columns-rows discrimination, a relationship that does not exist in transplant animals because of their normal learning curve and the consistent sparing of area 8. Injections of HRP into the visual cortex contralateral to the lesion result in variable numbers of labeled cells within the transplant. However, there is no consistent relationship between the number of transplant cells which project to the opposite hemisphere and learning of the discrimination. It is suggested that the learning deficit following the lesion is largely attentional and that the sparing of cortical area 8 (which in rats may include the analog of the frontal eye fields present in the primate cortex) contributes to the sparing of function.
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Affiliation(s)
- F Haun
- Department of Anatomy, Medical College of Pennsylvania/EPPI Division, Philadelphia 19129
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Thurlow GA, Cooper RM. Metabolic activity in striate and extrastriate cortex in the hooded rat: contralateral and ipsilateral eye input. J Comp Neurol 1988; 274:595-607. [PMID: 3220972 DOI: 10.1002/cne.902740408] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The extent of changes in glucose metabolism resulting from ipsilateral and contralateral eye activity in the posterior cortex of the hooded rat was demonstrated by means of the C-14 2-deoxyglucose autoradiographic technique. By stimulating one eye with square wave gratings and eliminating efferent activation from the other by means of enucleation or intraocular TTX injection, differences between ipsilaterally and contralaterally based visual activity in the two hemispheres were maximized. Carbon-14 levels in layer IV of autoradiographs of coronal sections were measured and combined across sections to form right and left matrices of posterior cortex metabolic activity. A difference matrix, formed by subtracting the metabolic activity matrix of cortex contralateral to the stimulated eye from the ipsilateral "depressed" matrix, emphasized those parts of the visual cortex that received monocular visual input. The demarcation of striate cortex by means of cholinesterase stain and the examination of autoradiographs from sections cut tangential to the cortical surface aided in the interpretation of the difference matrices. In striate cortex, differences were maximal in the medial monocular portion, and the lateral or binocular portion was shown to be divided metabolically into a far lateral contralaterally dominant strip along the cortical representation of the vertical meridian, and a more medial region of patches of more or less contralaterally dominant binocular input. Lateral peristriate differences were less than those of striate cortex, and regions of greater and lesser monocular input could be distinguished. We did not detect differences between the two hemispheres in either anterior or medial peristriate areas, thus indicating either completely binocular input (which seems unlikely given the retinotopic organization of these regions), or a greater dependence than in the lateral peristriate on inputs that were not affected by the visual manipulations.
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Affiliation(s)
- G A Thurlow
- Psychology Department, University of Calgary, Alberta, Canada
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Abstract
Normal rats and rats with devascularization lesions ranging from subtotal removals of striate cortex (Area 17) to complete removal of neocortex were trained in a horizontal/vertical stripe discrimination for a liquid reinforcer. Subgroups of animals were identified on the basis of size and location of lesion (with particular reference to striate cortex) as Subtotal, Striate, Posterior and Decorticate. Some animals in all of the lesion groups were able to acquire the discrimination, but there was a direct relationship between lesion size and number of training trials. Those animals which reached criterion on the original discrimination were trained on a second horizontal/vertical discrimination under either transfer or reversal conditions using 'rotated obliques' stimuli. Performance on this second discrimination indicated that animals from all lesion groups had been using visual stimuli based on stripe orientation in the original problem. Members of all lesion groups solved the rotated obliques problem under the transfer condition, though the speed and completeness with which they did so was again inversely related to lesion size. These data show high levels of visual competence in the absence of visual cortex even when stimuli thought to detect form discrimination are used and thus reinforce the view that superior colliculus may be a more significant visual area for the rat than was previously assumed. They also support other observations that animals do not use residual visual capacities without extensive experience and appropriate motivation.
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Silveira LC, Heywood CA, Cowey A. Contrast sensitivity and visual acuity of the pigmented rat determined electrophysiologically. Vision Res 1987; 27:1719-31. [PMID: 3445463 DOI: 10.1016/0042-6989(87)90101-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The contrast sensitivity function of the rat was assessed by investigating the relationship between the amplitude of visually evoked cortical potentials (VECP) and the spatial frequency and contrast of grating stimuli. Pattern reversal VECPs were recorded in Area 17 in the region of representation of the central binocular visual field. Transient responses were obtained with a 1 Hz contrast reversal. The mean contralateral monocular CSF peaked around 0.1 c/deg, with a threshold sensitivity of 20-25, low frequency attenuation and a high frequency cut-off of 1.18 c/deg. The mean binocular CSF showed a cut-off of 1.20 c/deg, which matches several behavioural measurements of visual acuity. The greater binocular sensitivity in the low frequency range (0.04 c/deg) could be tentatively attributed to the greater influence of the population of large ganglion cells that reaches its maximal density in the ipsilateral projection.
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Affiliation(s)
- L C Silveira
- Department of Physiology, Federal University of Pará, Belém, Brazil
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Legg CR. Spatial contrast and flicker sensitivity following medial thalamic or visual cortex lesions in hooded rats. Behav Brain Res 1986; 19:41-7. [PMID: 3954866 DOI: 10.1016/0166-4328(86)90046-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In rats, lesions of the medial thalamus that involve the intralaminar nuclei produce a number of visual impairments similar to those obtained with visual cortex ablation, suggesting that the former functionally disrupt visual cortex. This was tested by a direct comparison between the two lesions on spatial contrast and flicker sensitivity, using behavioural techniques. Both lesions depressed spatial contrast sensitivity, visual cortex damage more than thalamic lesions. Only medial thalamic lesions produced statistically significant changes in flicker sensitivity. This dissociation suggests that medial thalamic and visual cortex lesions are disrupting different mechanisms. Alternative explanations of the thalamic deficit are discussed.
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Dean P, Redgrave P. The superior colliculus and visual neglect in rat and hamster. II. Possible mechanisms. Brain Res 1984; 320:143-53. [PMID: 6395935 DOI: 10.1016/0165-0173(84)90003-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The observations that removal of the superior colliculus in rats and hamsters produces a striking visual neglect, whereas damage to striate cortex does not, require explanation in terms of the anatomy and physiology of visual pathways in these animals. One proposal is that neglect is produced because the superior colliculus is the only visual structure directly concerned with the production of orienting movements. However, recent behavioural evidence indicates that this mechanism on its own is insufficient: collicular neglect is not confined to orienting movements, but is in part an inability to register particular kinds of visual stimulus. Two additional mechanisms are considered. The superior colliculus receives visual information that the geniculostriate pathway does not. A variety of anatomical and electrophysiological evidence suggests that this is the case. Although the exact nature of the information is unclear, there is some suggestion that the superior colliculus has a stronger representation of the peripheral field than the geniculostriate pathway, and may be more concerned with small transient stimuli throughout the visual field. An intact superior colliculus is essential for normal functioning of the geniculostriate system. Anatomical evidence indicates that there are pathways whereby: (a) visual cortex could use the superior colliculus as an output station; and (b) the superior colliculus could control signals entering or leaving the geniculostriate system, although the nature of the information carried by the pathways is not yet understood. The precise contribution of these two additional mechanisms to collicular neglect remains to be determined. However, it may be conjectured that the first would underly the deficit in stimulus detection that appears to be one component of collicular neglect, whereas the second mechanism might underly an attentional component.
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Abstract
The development of visual acuity for vertically oriented gratings was followed in gerbil pups from 34 days of age until adulthood using a jumping stand procedure. Acuity was found to improve gradually from an initial level of about 0.7 cycles/degree to asymptotic values of 1.2-1.6 cycles/degree by 70 days of age. Acuity did not vary as a function of viewing distance over the range tested (17.5-46 cm). Practice was found to play some role in the acuity changes seen but cannot alone explain the results. The contributions of other performance variables and of neural development are considered.
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40
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Legg CR, Turkish S. Flicker sensitivity changes after subcortical visual system lesions in the rat. Behav Brain Res 1983; 10:311-24. [PMID: 6661281 DOI: 10.1016/0166-4328(83)90037-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Sensitivity to sinusoidal flicker, as a function of flicker frequency, was measured behaviourally in hooded rats by reducing modulation depth in a two-choice flicker versus no-flicker discrimination until subjects could not perform at above 80% correct. Analogous methods were used to measure spatial contrast sensitivity. In both tasks the display area was 24 x 20 degrees. Bilateral lesions were made in one of 4 structures; superior colliculus (SC), pretectum (PRT), posterior thalamus (PT), or ventral lateral geniculate nucleus (LGv). A fifth group served as sham operated controls. On the basis of histology the LGv group was subdivided according to presence or absence of optic tract damage. PT, PRT and LGv lesions produced a statistically significant depression in flicker sensitivity, the impairment in the LGv sub-group with optic tract damage being significantly greater than that in the LGv group with optic tract sparing. In the latter, post-operative sensitivity correlated significantly with amount of surviving tissue in the thalamic radiations but not with surviving LGv itself. PRT and LGv lesions that involved the optic tract also significantly depressed spatial contract sensitivity. The implications of the finding, that PT and LGv lesions may depress flicker sensitivity without affecting spatial vision, for interpretation of the effects of comparable lesions on suprathreshold discrimination are discussed.
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Reese BE, Cowey A. Projection lines and the ipsilateral retino-geniculate pathway in the hooded rat. Neuroscience 1983; 10:1233-47. [PMID: 6664492 DOI: 10.1016/0306-4522(83)90110-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The organization of the hooded rat's dorsal lateral geniculate nucleus was studied with anatomical techniques, with particular regard to the representation of temporal retina and the binocular field. The ipsilateral and contralateral retinal terminal fields were examined in three stereotaxic planes following injections of horseradish peroxidase into the eye. Projections arising from the temporal crescent of the retina were studied with silver staining techniques for anterograde degeneration products. Following discrete retinal lesions there was clear evidence that the temporal retina projects in a topographic fashion both ipsilaterally and contralaterally. The orientation of the lines of projection in the dorsal lateral geniculate nucleus was assessed by retrograde labelling of cells after cortical implants of horseradish peroxidase. Although both the lines of projection and the ipsilateral terminal field extend rostro-caudally in the dorsal lateral geniculate nucleus, their paths are oblique rather than parallel. Their intersection appears to correspond to the representation in this nucleus of conjugate retinal points. This was confirmed by administering horseradish peroxidase by iontophoresis in either the binocular or monocular representation of the primary visual cortex, while one eye received an injection of [3H]proline. Only those cortical injections in the binocular region gave rise to labelled projection lines passing through the autoradiographically-labelled ipsilateral terminal field. The rat's dorsal lateral geniculate nucleus displays none of the cytoarchitectural lamination which is so prominent in the primate and cat. Even after labelling the input to the nucleus from one eye, there is still no obvious laminar relationship between the terminal fields from the two eyes. Despite the absence of lamination, the current results suggest that the principle of apposing the representation of conjugate retinal points in the dorsal lateral geniculate nucleus is the same in the rat as in cat and monkey.
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Abstract
Retinal ganglion cells were labeled with horseradish peroxidase injected into the superior colliculus of normal pigmented rats. It is shown that virtually all ganglion cells with crossed axons project to the tectum, thus including all cell types described so far in the rat. The results contrast with the conclusion that only one-third of the ganglion cell population project to the tectum in normal hamsters.
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Abstract
A method for recording pattern reversal evoked potentials (PREPs) from awake restrained rats has been developed. The procedure of Onofrj et al. [26] was modified to eliminate the need for anesthetic, thereby avoiding possible interactions of the anesthetic with other manipulations of interest. Rats were restrained in a harness and placed in front of a pattern generating TV screen displaying a black and white alternating square wave grating. Using various stimulation and recording parameters, normative data are presented from 141 adult male Long-Evans hooded and 11 adult male Sprague-Dawley albino rats. Reliable waveforms were recorded with five identifiable peaks. The labels and mean latencies of these peaks in hooded rats were: N1, 47.3 msec; P1, 65.7 msec; N2, 83.3 msec; P2, 94.4 msec; and N3, 129.8 msec. Spatial acuity functions generated with PREPs gave acuity estimates which corresponded closely to values determined behaviorally for hooded and albino rats [4,11].
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Legg CR, Turkish S. Spatial contrast sensitivity changes after subcortical visual system lesions in the rat. Behav Brain Res 1983; 7:253-9. [PMID: 6830654 DOI: 10.1016/0166-4328(83)90195-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Spatial contrast sensitivity functions were determined in hooded rats after lesions involving the pretectum (PRT), rostral pretectum and adjacent medial thalamus (PRT +), posterior thalamus (PT), or ventral lateral geniculate nucleus (LGv). PRT and PRT + lesions depressed sensitivity at both high and low spatial frequencies but the high frequency loss was much greater in the latter group. PT lesions depressed sensitivity to frequencies of 0.45 cycles/deg. and above but had no detectable effect upon low frequencies while LGv lesions depressed sensitivity to both high and low frequencies. The discussion relates these results to previous reports of discrimination learning impairments after comparable lesions.
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McDaniel WF, Coleman J, Lindsay JF. A comparison of lateral peristriate and striate neocortical ablations in the rat. Behav Brain Res 1982; 6:249-72. [PMID: 7171386 DOI: 10.1016/0166-4328(82)90027-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The effects of striate, lateral peristriate and sham ablations upon the post-operative reacquisition of visual discriminations were studied in two experiments. The results of Experiment 1 indicated that lesions restricted to the lateral peristriate neocortex rendered the rat incapable of resolving an oblique stripe discrimination. Seven of the 9 rats with striate ablations were unable to form the discrimination. The histological findings indicated that the deficit following lateral peristriate injury was not due to interruption of the geniculostriate system. However, the behavioral impairment in destriate rats corresponded to the degree of unintentional injury in lateral peristriate neocortex, but not medial peristriate tissue. In Experiment 2, the effects of these lesions were studied upon the post-operative reacquisition of either a non-reversal or reversal of a preoperatively acquired brightness discrimination. Animals with striate damage demonstrated considerable savings on the non-reversed brightness discrimination, and they acquired the reversal at a rate equal to that seen in animals with sham ablations. Rats with peristriate ablations showed no savings on the non-reversed brightness habit, and they required more extensive training than both the striate and sham groups on the reversal. These findings suggest that the frequently reported loss of a preoperative brightness habit following large posterior neocortex ablations is due to damage in the lateral peristriate neocortex rather than damage of the geniculostriate system. These results, taken with other literature, suggest an important role of the lateral peristriate neocortex in visuospatial sensory function.
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