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Merlin S, Vidyasagar T. Optogenetics in primate cortical networks. Front Neuroanat 2023; 17:1193949. [PMID: 37284061 PMCID: PMC10239886 DOI: 10.3389/fnana.2023.1193949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 05/08/2023] [Indexed: 06/08/2023] Open
Abstract
The implementation of optogenetics in studies on non-human primates has generally proven quite difficult, but recent successes have paved the way for its rapid increase. Limitations in the genetic tractability in primates, have been somewhat overcome by implementing tailored vectors and promoters to maximize expression and specificity in primates. More recently, implantable devices, including microLED arrays, have made it possible to deliver light deeper into brain tissue, allowing targeting of deeper structures. However, the greatest limitation in applying optogenetics to the primate brain is the complex connections that exist within many neural circuits. In the past, relatively cruder methods such as cooling or pharmacological blockade have been used to examine neural circuit functions, though their limitations were well recognized. In some ways, similar shortcomings remain for optogenetics, with the ability to target a single component of complex neural circuits being the greatest challenge in applying optogenetics to systems neuroscience in primate brains. Despite this, some recent approaches combining Cre-expressing and Cre-dependent vectors have overcome some of these limitations. Here we suggest that optogenetics provides its greatest advantage to systems neuroscientists when applied as a specific tool to complement the techniques of the past, rather than necessarily replacing them.
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Affiliation(s)
- Sam Merlin
- Medical Science, School of Science, Western Sydney University, Campbelltown, NSW, Australia
| | - Trichur Vidyasagar
- Department of Optometry and Vision Sciences, School of Health Science, The University of Melbourne, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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Morphological evidence for multiple distinct channels of corticogeniculate feedback originating in mid-level extrastriate visual areas of the ferret. Brain Struct Funct 2021; 226:2777-2791. [PMID: 34636984 PMCID: PMC9845063 DOI: 10.1007/s00429-021-02385-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/11/2021] [Indexed: 01/19/2023]
Abstract
Complementary reciprocal feedforward and feedback circuits connecting the visual thalamus with the visual cortex are essential for visual perception. These circuits predominantly connect primary and secondary visual cortex with the dorsal lateral geniculate nucleus (LGN). Although there are direct geniculocortical inputs to extrastriate visual cortex, whether reciprocal corticogeniculate neurons exist in extrastriate cortex is not known. Here we utilized virus-mediated retrograde tracing to reveal the presence of corticogeniculate neurons in three mid-level extrastriate visual cortical areas in ferrets: PMLS, PLLS, and 21a. We observed corticogeniculate neurons in all three extrastriate areas, although the density of virus-labeled corticogeniculate neurons in extrastriate cortex was an order of magnitude less than that in areas 17 and 18. A cluster analysis of morphological metrics quantified following reconstructions of the full dendritic arborizations of virus-labeled corticogeniculate neurons revealed six distinct cell types. Similar corticogeniculate cell types to those observed in areas 17 and 18 were also observed in PMLS, PLLS, and 21a. However, these unique cell types were not equally distributed across the three extrastriate areas. The majority of corticogeniculate neurons per cluster originated in a single area, suggesting unique parallel organizations for corticogeniculate feedback from each extrastriate area to the LGN. Together, our findings demonstrate direct feedback connections from mid-level extrastriate visual cortex to the LGN, supporting complementary reciprocal circuits at multiple processing stages along the visual hierarchy. Importantly, direct reciprocal connections between the LGN and extrastriate cortex, that bypass V1, could provide a substrate for residual vision following V1 damage.
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Is the primary visual cortex necessary for blindsight-like behavior? Review of transcranial magnetic stimulation studies in neurologically healthy individuals. Neurosci Biobehav Rev 2021; 127:353-364. [PMID: 33965459 DOI: 10.1016/j.neubiorev.2021.04.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 12/20/2022]
Abstract
The visual pathways that bypass the primary visual cortex (V1) are often assumed to support visually guided behavior in humans in the absence of conscious vision. This conclusion is largely based on findings on patients: V1 lesions cause blindness but sometimes leave some visually guided behaviors intact-this is known as blindsight. With the aim of examining how well the findings on blindsight patients generalize to neurologically healthy individuals, we review studies which have tried to uncover transcranial magnetic stimulation (TMS) induced blindsight. In general, these studies have failed to demonstrate a completely unconscious blindsight-like capacity in neurologically healthy individuals. A possible exception to this is TMS-induced blindsight of stimulus presence or location. Because blindsight in patients is often associated with some form of introspective access to the visual stimulus, and blindsight may be associated with neural reorganization, we suggest that rather than revealing a dissociation between visually guided behavior and conscious seeing, blindsight may reflect preservation or partial recovery of conscious visual perception after the lesion.
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Schmuker M, Kupper R, Aertsen A, Wachtler T, Gewaltig MO. Feed-forward and noise-tolerant detection of feature homogeneity in spiking networks with a latency code. BIOLOGICAL CYBERNETICS 2021; 115:161-176. [PMID: 33787967 DOI: 10.1007/s00422-021-00866-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
In studies of the visual system as well as in computer vision, the focus is often on contrast edges. However, the primate visual system contains a large number of cells that are insensitive to spatial contrast and, instead, respond to uniform homogeneous illumination of their visual field. The purpose of this information remains unclear. Here, we propose a mechanism that detects feature homogeneity in visual areas, based on latency coding and spike time coincidence, in a purely feed-forward and therefore rapid manner. We demonstrate how homogeneity information can interact with information on contrast edges to potentially support rapid image segmentation. Furthermore, we analyze how neuronal crosstalk (noise) affects the mechanism's performance. We show that the detrimental effects of crosstalk can be partly mitigated through delayed feed-forward inhibition that shapes bi-phasic post-synaptic events. The delay of the feed-forward inhibition allows effectively controlling the size of the temporal integration window and, thereby, the coincidence threshold. The proposed model is based on single-spike latency codes in a purely feed-forward architecture that supports low-latency processing, making it an attractive scheme of computation in spiking neuronal networks where rapid responses and low spike counts are desired.
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Affiliation(s)
- Michael Schmuker
- Honda Research Institute Europe GmbH, Offenbach am Main, Germany.
- Department of Computer Science, Biocomputation Group, University of Hertfordshire, Hatfield, UK.
| | - Rüdiger Kupper
- Honda Research Institute Europe GmbH, Offenbach am Main, Germany
| | - Ad Aertsen
- Bernstein-Center Freiburg and Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Thomas Wachtler
- Department of Biology II, Ludwig-Maximilians-Universität München, München, Germany
| | - Marc-Oliver Gewaltig
- Honda Research Institute Europe GmbH, Offenbach am Main, Germany
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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5
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Altered Structural Connectivity of the Left Visual Thalamus in Developmental Dyslexia. Curr Biol 2017; 27:3692-3698.e4. [PMID: 29153326 DOI: 10.1016/j.cub.2017.10.034] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/13/2017] [Accepted: 10/11/2017] [Indexed: 11/22/2022]
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Towards building a more complex view of the lateral geniculate nucleus: Recent advances in understanding its role. Prog Neurobiol 2017. [DOI: 10.1016/j.pneurobio.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Gaglianese A, Harvey BM, Vansteensel MJ, Dumoulin SO, Ramsey NF, Petridou N. Separate spatial and temporal frequency tuning to visual motion in human MT+ measured with ECoG. Hum Brain Mapp 2016; 38:293-307. [PMID: 27647579 DOI: 10.1002/hbm.23361] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/10/2016] [Accepted: 08/21/2016] [Indexed: 11/11/2022] Open
Abstract
The human middle temporal complex (hMT+) has a crucial biological relevance for the processing and detection of direction and speed of motion in visual stimuli. Here, we characterized how neuronal populations in hMT+ encode the speed of moving visual stimuli. We evaluated human intracranial electrocorticography (ECoG) responses elicited by square-wave dartboard moving stimuli with different spatial and temporal frequency to investigate whether hMT+ neuronal populations encode the stimulus speed directly, or whether they separate motion into its spatial and temporal components. We extracted two components from the ECoG responses: (1) the power in the high-frequency band (HFB: 65-95 Hz) as a measure of the neuronal population spiking activity and (2) a specific spectral component that followed the frequency of the stimulus's contrast reversals (SCR responses). Our results revealed that HFB neuronal population responses to visual motion stimuli exhibit distinct and independent selectivity for spatial and temporal frequencies of the visual stimuli rather than direct speed tuning. The SCR responses did not encode the speed or the spatiotemporal frequency of the visual stimuli. We conclude that the neuronal populations measured in hMT+ are not directly tuned to stimulus speed, but instead encode speed through separate and independent spatial and temporal frequency tuning. Hum Brain Mapp 38:293-307, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Anna Gaglianese
- Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands.,Department of Radiology, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Ben M Harvey
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, 3584 CS, The Netherlands
| | - Mariska J Vansteensel
- Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Serge O Dumoulin
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, 3584 CS, The Netherlands
| | - Nick F Ramsey
- Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Natalia Petridou
- Department of Radiology, University Medical Center Utrecht, Utrecht, 3584 CX, The Netherlands
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Hagan MA, Rosa MGP, Lui LL. Neural plasticity following lesions of the primate occipital lobe: The marmoset as an animal model for studies of blindsight. Dev Neurobiol 2016; 77:314-327. [PMID: 27479288 DOI: 10.1002/dneu.22426] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/21/2016] [Accepted: 07/29/2016] [Indexed: 12/15/2022]
Abstract
For nearly a century it has been observed that some residual visually guided behavior can persist after damage to the primary visual cortex (V1) in primates. The age at which damage to V1 occurs leads to different outcomes, with V1 lesions in infancy allowing better preservation of visual faculties in comparison with those incurred in adulthood. While adult V1 lesions may still allow retention of some limited visual abilities, these are subconscious-a characteristic that has led to this form of residual vision being referred to as blindsight. The neural basis of blindsight has been of great interest to the neuroscience community, with particular focus on understanding the contributions of the different subcortical pathways and cortical areas that may underlie this phenomenon. More recently, research has started to address which forms of neural plasticity occur following V1 lesions at different ages, including work using marmoset monkeys. The relatively rapid postnatal development of this species, allied to the lissencephalic brains and well-characterized visual cortex provide significant technical advantages, which allow controlled experiments exploring visual function in the absence of V1. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 314-327, 2017.
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Affiliation(s)
- Maureen A Hagan
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
| | - Marcello G P Rosa
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
| | - Leo L Lui
- Department of Physiology, Monash University, Victoria, 3800, Australia.,Neuroscience Program, Biomedicine Discovery Institute, Monash University, Victoria, 3800, Australia.,Australian Research Council, Centre of Excellence for Integrative Brain Function, Monash University Node, Victoria, 3800, Australia
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Abstract
UNLABELLED Signals from cones are recombined in postreceptoral channels [luminance, L + M; red-green, L - M; blue-yellow, S - (L + M)]. The melanopsin-containing retinal ganglion cells are also active at daytime light levels and recent psychophysical results suggest that melanopsin contributes to conscious vision in humans. Here, we measured BOLD fMRI responses to spectral modulations that separately targeted the postreceptoral cone channels and melanopsin. Responses to spatially uniform (27.5° field size, central 5° obscured) flicker at 0.5, 1, 2, 4, 8, 16, 32, and 64 Hz were recorded from areas V1, V2/V3, motion-sensitive area MT, and the lateral occipital complex. In V1 and V2/V3, higher temporal sensitivity was observed to L + M + S (16 Hz) compared with L - M flicker (8 Hz), consistent with psychophysical findings. Area MT was most sensitive to rapid (32 Hz) flicker of either L + M + S or L - M. We found S cone responses only in areas V1 and V2/V3 (peak frequency: 4-8 Hz). In addition, we studied an L + M modulation and found responses that were effectively identical at all temporal frequencies to those recorded for the L + M + S modulation. Finally, we measured the cortical response to melanopsin-directed flicker and compared this response with control modulations that addressed stimulus imprecision and the possibility of stimulation of cones in the shadow of retinal blood vessels (penumbral cones). For our stimulus conditions, melanopsin flicker did not elicit a cortical response exceeding that of the control modulations. We note that failure to control for penumbral cone stimulation could be mistaken for a melanopsin response. SIGNIFICANCE STATEMENT The retina contains cone photoreceptors and ganglion cells that contain the photopigment melanopsin. Cones provide brightness and color signals to visual cortex. Melanopsin influences circadian rhythm and the pupil, but its contribution to cortex and perception is less clear. We measured the response of human visual cortex with fMRI using spectral modulations tailored to stimulate the cones and melanopsin separately. We found that cortical responses to cone signals vary systematically across visual areas. Differences in temporal sensitivity for achromatic, red-green, and blue-yellow stimuli generally reflect the known perceptual properties of vision. We found that melanopsin signals do not produce a measurable response in visual cortex at temporal frequencies between 0.5 and 64 Hz at daytime light levels.
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Adams RB, Kveraga K. Social Vision: Functional Forecasting and the Integration of Compound Social Cues. ACTA ACUST UNITED AC 2015; 6:591-610. [PMID: 29242738 DOI: 10.1007/s13164-015-0256-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
For decades the study of social perception was largely compartmentalized by type of social cue: race, gender, emotion, eye gaze, body language, facial expression etc. This was partly due to good scientific practice (e.g., controlling for extraneous variability), and partly due to assumptions that each type of social cue was functionally distinct from others. Herein, we present a functional forecast approach to understanding compound social cue processing that emphasizes the importance of shared social affordances across various cues (see too Adams, Franklin, Nelson, & Stevenson, 2010; Adams & Nelson, 2011; Weisbuch & Adams, 2012). We review the traditional theories of emotion and face processing that argued for dissociable and noninteracting pathways (e.g., for specific emotional expressions, gaze, identity cues), as well as more recent evidence for combinatorial processing of social cues. We argue here that early, and presumably reflexive, visual integration of such cues is necessary for adaptive behavioral responding to others. In support of this claim, we review contemporary work that reveals a flexible visual system, one that readily incorporates meaningful contextual influences in even nonsocial visual processing, thereby establishing the functional and neuroanatomical bases necessary for compound social cue integration. Finally, we explicate three likely mechanisms driving such integration. Together, this work implicates a role for cognitive penetrability in visual perceptual abilities that have often been (and in some cases still are) ascribed to direct encapsulated perceptual processes.
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Affiliation(s)
- Reginald B Adams
- Department of Psychology, The Pennsylvania State University, University Park, PA, USA
| | - Kestutis Kveraga
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Gaglianese A, Costagli M, Ueno K, Ricciardi E, Bernardi G, Pietrini P, Cheng K. The direct, not V1-mediated, functional influence between the thalamus and middle temporal complex in the human brain is modulated by the speed of visual motion. Neuroscience 2015; 284:833-844. [DOI: 10.1016/j.neuroscience.2014.10.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/26/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
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12
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Antidromic latency of magnocellular, parvocellular, and koniocellular (Blue-ON) geniculocortical relay cells in marmosets. Vis Neurosci 2014; 31:263-73. [DOI: 10.1017/s0952523814000066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractWe studied the functional connectivity of cells in the lateral geniculate nucleus (LGN) with the primary visual cortex (V1) in anesthetized marmosets (Callithrix jacchus). The LGN sends signals to V1 along parallel visual pathways called parvocellular (P), magnocellular (M), and koniocellular (K). To better understand how these pathways provide inputs to V1, we antidromically activated relay cells in the LGN by electrically stimulating V1 and measuring the conduction latencies of P (n = 7), M (n = 14), and the “Blue-ON” (n = 5) subgroup of K cells (K-BON cells). We found that the antidromic latencies of K-BON cells were similar to those of P cells. We also measured the response latencies to high contrast visual stimuli for a subset of cells. We found the LGN cells that have the shortest latency of response to visual stimulation also have the shortest antidromic latencies. We conclude that Blue color signals are transmitted directly to V1 from the LGN by K-BON cells.
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Abstract
Explanations for color phenomena are often sought in the retina, lateral geniculate nucleus, and V1, yet it is becoming increasingly clear that a complete account will take us further along the visual-processing pathway. Working out which areas are involved is not trivial. Responses to S-cone activation are often assumed to indicate that an area or neuron is involved in color perception. However, work tracing S-cone signals into extrastriate cortex has challenged this assumption: S-cone responses have been found in brain regions, such as the middle temporal (MT) motion area, not thought to play a major role in color perception. Here, we review the processing of S-cone signals across cortex and present original data on S-cone responses measured with fMRI in alert macaque, focusing on one area in which S-cone signals seem likely to contribute to color (V4/posterior inferior temporal cortex) and on one area in which S signals are unlikely to play a role in color (MT). We advance a hypothesis that the S-cone signals in color-computing areas are required to achieve a balanced neural representation of perceptual color space, whereas those in noncolor-areas provide a cue to illumination (not luminance) and confer sensitivity to the chromatic contrast generated by natural daylight (shadows, illuminated by ambient sky, surrounded by direct sunlight). This sensitivity would facilitate the extraction of shape-from-shadow signals to benefit global scene analysis and motion perception.
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Krug K. No blind alleys for blindsight: multiple active pathways into extrastriate cortex. J Physiol 2013; 591:5-6. [PMID: 23281483 DOI: 10.1113/jphysiol.2012.246959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Kristine Krug
- Oxford University, Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK.
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