Mechanism underpinning the sharpening of orientation and spatial frequency selectivities in the tree shrew (Tupaia belangeri) primary visual cortex

Mohan, Yamni S; Viswanathan, Sivaram; Jayakumar, Jaikishan; Lloyd, Errol K.J.; Vidyasagar, T. R.

doi:10.1007/s00429-021-02445-y

Cited by 5 publications

(3 citation statements)

References 56 publications

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“…We use tree shrews as an animal model in this study, as they are a diurnal mammalian species closely related to primates that have multiple advantages for the translational study of visual prosthetics. For example, tree shrew V1 has a large surface area of 4000 mm 2 and exhibits orientation columns and shares many other aspects of functional organization with primates ( Fitzpatrick, 1996 ; Khani et al, 2018 ; Mohan et al, 2022 ; Veit et al, 2011 ). Their retina is composed largely of cones ( Muller et al, 1989 ), which is useful for prosthetic work as humans tend to illuminate their environments; they are a diurnal mammal that is highly reliant on vision ( Emmons, 2000 ) and can readily be trained on cognitive visually based behavioral tasks ( Mustafar et al, 2018 ; Schumacher et al, 2022 ).…”

Section: Introductionmentioning

confidence: 99%

Optogenetic activation of visual thalamus generates artificial visual percepts

Wang,

Azimi,

Zhao

et al. 2023

eLife

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The lateral geniculate nucleus (LGN), a retinotopic relay center where visual inputs from the retina are processed and relayed to the visual cortex, has been proposed as a potential target for artificial vision. At present, it is unknown whether optogenetic LGN stimulation is sufficient to elicit behaviorally relevant percepts, and the properties of LGN neural responses relevant for artificial vision have not been thoroughly characterized. Here, we demonstrate that tree shrews pretrained on a visual detection task can detect optogenetic LGN activation using an AAV2-CamKIIα-ChR2 construct and readily generalize from visual to optogenetic detection. Simultaneous recordings of LGN spiking activity and primary visual cortex (V1) local field potentials (LFP) during optogenetic LGN stimulation show that LGN neurons reliably follow optogenetic stimulation at frequencies up to 60 Hz, and uncovered a striking phase locking between the V1 local field potential (LFP) and the evoked spiking activity in LGN. These phase relationships were maintained over a broad range of LGN stimulation frequencies, up to 80 Hz, with spike field coherence values favoring higher frequencies, indicating the ability to relay temporally precise information to V1 using light activation of the LGN. Finally, V1 LFP responses showed sensitivity values to LGN optogenetic activation that were similar to the animal's behavioral performance. Taken together, our findings confirm the LGN as a potential target for visual prosthetics in a highly visual mammal closely related to primates.

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Section: Introductionmentioning

confidence: 99%

Optogenetic activation of visual thalamus generates artificial visual percepts

Wang,

Azimi,

Zhao

et al. 2023

eLife

View full text Add to dashboard Cite

show abstract

“…We use tree shrews as an animal model in this study, as they are a diurnal mammalian species closely related to primates and humans that have multiple advantages for the translational study of visual prosthetics. For example, tree shrew V1 has a large surface area of 4000 mm 2 and exhibits orientation columns and shares many other aspects of functional organization with primates and humans [25][26][27][28] . Their retina is composed largely of cones 29 , which is useful for prosthetic work as humans tend to illuminate their environments; they are a diurnal mammal that is highly reliant on vision 30 and can readily be trained on cognitive visually based behavioral tasks 31,32 .…”

Section: Introductionmentioning

confidence: 99%

Optogenetic activation of visual thalamus generates artificial visual percepts

Wang

Azimi

Zhao

et al. 2022

Preprint

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The lateral geniculate nucleus (LGN), a retinotopic relay center where visual inputs from the retina are processed and relayed to the visual cortex, has been proposed as a potential target for artificial vision. At present, it is unknown whether optogenetic LGN stimulation is sufficient to elicit behaviorally relevant percepts and the properties of LGN neural responses relevant for artificial vision have not been thoroughly characterized. Here, we demonstrate that tree shrews pretrained on a visual detection task can detect optogenetic LGN activation using an AAV2-CamKIIα-ChR2 construct and readily generalize from visual to optogenetic detection. We also characterize how amplitude and frequency of optogenetic stimulation affect behavioral performance. Given the importance of temporal stimulation parameters, we also study tree shrew behavioral ability to discriminate among pairs of visual flicker frequencies and demonstrate performance transfer among related discrimination problems as well as limitations. Neural recordings in LGN and primary visual cortex (V1) examining two flicker discriminations reveal that while LGN neurons multiplex information about temporal stimulation discriminations, V1 neurons explicitly encode information about one or the other discriminations but not both. Our findings confirm the LGN as a potential target for visual prosthetics and introduce a distinction in stimulus encoding between thalamic and cortical representations that could be of fundamental importance in artificial vision.

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“…The functionalities of the LGN are enabled by cells with special receptive fields, which are the foundation of positional and orientational recognition. [19,20] Light-stimulated synaptic devices [21][22][23][24] based on various materials such as metal oxides, [25][26][27][28] photoinduced phase-change materials, [29,30] organic materials, [31,32] 2D materials, [33] Si nanocrystals, [34,35] Si on insulator (SOI), [36] and organic halide perovskite (OHP) [37,38] have been fabricated to simulate the functionalities of the retina and visual cortex. However, few reports exist on the development of light-stimulated synaptic devices that mimic the functionalities of the LGN cells.…”

mentioning

confidence: 99%

An Array of Light‐Stimulated Two‐Terminal Synaptic Devices with the Modulation of Electric Polarity

Liu

Huang

Wang

et al. 2022

Adv Funct Materials

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Neuromorphic visual systems based on optoelectronic synaptic devices have been recently studied to simulate the retina and visual cortex of a human being. Now it is shown that an array of optoelectronic synaptic devices based on the two‐terminal structure of Si/perovskite/Au may mimic the functionalities of lateral geniculate nucleus (LGN) cells. Benefiting from the photovoltaic effect, the devices can work under a self‐powered mode. Diverse synaptic functionalities such as postsynaptic current, paired‐pulse facilitation/depression, spike duration‐dependent plasticity, spike number‐dependent plasticity, and spike rate‐dependent plasticity have been simulated. By modulating the electric bias of the devices in the array the simulation of the positional and orientational recognition of the LGN cells is demonstrated.

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Mechanism underpinning the sharpening of orientation and spatial frequency selectivities in the tree shrew (Tupaia belangeri) primary visual cortex

Cited by 5 publications

References 56 publications

Optogenetic activation of visual thalamus generates artificial visual percepts

Optogenetic activation of visual thalamus generates artificial visual percepts

Optogenetic activation of visual thalamus generates artificial visual percepts

An Array of Light‐Stimulated Two‐Terminal Synaptic Devices with the Modulation of Electric Polarity

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