Contextual feedback to V1 neurons shapes binocular matching

AbstractLearning-activated engram neurons play a critical role in memory recall. An untested hypothesis is that these same neurons play an instructive role in offline memory consolidation. Here we show that a visually-cued fear memory is consolidated during post-conditioning sleep in mice. We then use TRAP (targeted recombination in active populations) to genetically label or optogenetically manipulate primary visual cortex (V1) neurons responsive to the visual cue. Following fear conditioning, mice respond to activation of this visual engram population in a manner similar to visual presentation of fear cues. Cue-responsive neurons are selectively reactivated in V1 during post-conditioning sleep. Mimicking visual engram reactivation optogenetically leads to increased representation of the visual cue in V1. Optogenetic inhibition of the engram population during post-conditioning sleep disrupts consolidation of fear memory. We conclude that selective sleep-associated reactivation of learning-activated sensory populations serves as a necessary instructive mechanism for memory consolidation.

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A direct interareal feedback-to-feedforward circuit in primate visual cortex

Nature Communications ◽

10.1038/s41467-021-24928-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Caitlin Siu ◽

Justin Balsor ◽

Sam Merlin ◽

Frederick Federer ◽

Alessandra Angelucci

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Projection Neurons ◽

V1 Neurons ◽

Cortical Areas ◽

Area V2 ◽

Computational Work ◽

Primate Visual Cortex ◽

Similar Area ◽

Hierarchical Computation

AbstractThe mammalian sensory neocortex consists of hierarchically organized areas reciprocally connected via feedforward (FF) and feedback (FB) circuits. Several theories of hierarchical computation ascribe the bulk of the computational work of the cortex to looped FF-FB circuits between pairs of cortical areas. However, whether such corticocortical loops exist remains unclear. In higher mammals, individual FF-projection neurons send afferents almost exclusively to a single higher-level area. However, it is unclear whether FB-projection neurons show similar area-specificity, and whether they influence FF-projection neurons directly or indirectly. Using viral-mediated monosynaptic circuit tracing in macaque primary visual cortex (V1), we show that V1 neurons sending FF projections to area V2 receive monosynaptic FB inputs from V2, but not other V1-projecting areas. We also find monosynaptic FB-to-FB neuron contacts as a second motif of FB connectivity. Our results support the existence of FF-FB loops in primate cortex, and suggest that FB can rapidly and selectively influence the activity of incoming FF signals.

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Robust Temporal Coding of Contrast by V1 Neurons for Transient But Not for Steady-State Stimuli

Journal of Neuroscience ◽

10.1523/jneurosci.18-16-06583.1998 ◽

1998 ◽

Vol 18 (16) ◽

pp. 6583-6598 ◽

Cited By ~ 56

Author(s):

Ferenc Mechler ◽

Jonathan D. Victor ◽

Keith P. Purpura ◽

Robert Shapley

Keyword(s):

Steady State ◽

Temporal Coding ◽

V1 Neurons

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Differential contributions of magnocellular and parvocellular pathways to the contrast response of neurons in bush baby primary visual cortex (V1)

Visual Neuroscience ◽

10.1017/s095252380017107x ◽

2000 ◽

Vol 17 (1) ◽

pp. 71-76 ◽

Cited By ~ 22

Author(s):

JOHN D. ALLISON ◽

PETER MELZER ◽

YUCHUAN DING ◽

A.B. BONDS ◽

VIVIEN A. CASAGRANDE

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Response Amplitude ◽

Contrast Threshold ◽

Peak Response ◽

V1 Neurons ◽

Bush Baby ◽

High Stimulus ◽

Average Contrast ◽

Contrast Response

How neurons in the primary visual cortex (V1) of primates process parallel inputs from the magnocellular (M) and parvocellular (P) layers of the lateral geniculate nucleus (LGN) is not completely understood. To investigate whether signals from the two pathways are integrated in the cortex, we recorded contrast-response functions (CRFs) from 20 bush baby V1 neurons before, during, and after pharmacologically inactivating neural activity in either the contralateral LGN M or P layers. Inactivating the M layer reduced the responses of V1 neurons (n = 10) to all stimulus contrasts and significantly elevated (t = 8.15, P < 0.01) their average contrast threshold from 8.04 (± 4.1)% contrast to 22.46 (± 6.28)% contrast. M layer inactivation also significantly reduced (t = 4.06, P < 0.01) the average peak response amplitude. Inactivating the P layer did not elevate the average contrast threshold of V1 neurons (n = 10), but significantly reduced (t = 4.34, P < 0.01) their average peak response amplitude. These data demonstrate that input from the M pathway can account for the responses of V1 neurons to low stimulus contrasts and also contributes to responses to high stimulus contrasts. The P pathway appears to influence mainly the responses of V1 neurons to high stimulus contrasts. None of the cells in our sample, which included cells in all output layers of V1, appeared to receive input from only one pathway. These findings support the view that many V1 neurons integrate information about stimulus contrast carried by the LGN M and P pathways.

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Organization of Binocular Pathways: Modeling and Data Related to Rivalry

Neural Computation ◽

10.1162/neco.1991.3.1.44 ◽

1991 ◽

Vol 3 (1) ◽

pp. 44-53 ◽

Cited By ~ 23

Author(s):

Sidney R. Lehky ◽

Randolph Blake

Keyword(s):

Lateral Geniculate Nucleus ◽

Binocular Rivalry ◽

Striate Cortex ◽

Reciprocal Inhibition ◽

Lateral Geniculate ◽

Layer 4 ◽

Inhibitory Coupling ◽

Binocular Matching

It is proposed that inputs to binocular cells are gated by reciprocal inhibition between neurons located either in the lateral geniculate nucleus or in layer 4 of striate cortex. The strength of inhibitory coupling in the gating circuitry is modulated by layer 6 neurons, which are the outputs of binocular matching circuitry. If binocular inputs are matched, the inhibition is modulated to be weak, leading to fused vision, whereas if the binocular inputs are unmatched, inhibition is modulated to be strong, leading to rivalrous oscillations. These proposals are buttressed by psychophysical experiments measuring the strength of adaptational aftereffects following exposure to an adapting stimulus visible only intermittently during binocular rivalry.

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Amodal Completion and the Perception of Depth without Binocular Correspondence

Perception ◽

10.1068/p3305 ◽

2002 ◽

Vol 31 (9) ◽

pp. 1037-1045 ◽

Cited By ~ 11

Author(s):

Benoit A Bacon ◽

Pascal Mamassian

Keyword(s):

Amodal Completion ◽

Correspondence Problem ◽

Illusory Contours ◽

Binocular Matching ◽

Partially Occluded ◽

Global Surface

Half-occlusions and illusory contours have recently been used to show that depth can be perceived in the absence of binocular correspondence and that there is more to stereopsis than solving the correspondence problem. In the present study we show a new way for depth to be assigned in the absence of binocular correspondence, namely amodal completion. Although an occluder removed all possibility of direct binocular matching, subjects consistently assigned the correct depth (convexity or concavity) to partially occluded ‘folded cards’ stimuli. Our results highlight the importance of more global, surface-based processes in stereopsis.

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Effect of Interocular Delay on Disparity-Selective V1 Neurons: Relationship to Stereoacuity and the Pulfrich Effect

Journal of Neurophysiology ◽

10.1152/jn.01177.2004 ◽

2005 ◽

Vol 94 (2) ◽

pp. 1541-1553 ◽

Cited By ~ 17

Author(s):

Jenny C. A. Read ◽

Bruce G. Cumming

Keyword(s):

Stereo Matching ◽

Striate Cortex ◽

Temporal Integration ◽

Gaussian Function ◽

Great Majority ◽

Integration Time ◽

V1 Neurons ◽

Temporal Properties ◽

Pulfrich Effect ◽

Behaving Monkeys

The temporal properties of disparity-sensitive neurons place important temporal constraints on stereo matching. We examined these constraints by measuring the responses of disparity-selective neurons in striate cortex of awake behaving monkeys to random-dot stereograms that contained interocular delays. Disparity selectivity was gradually abolished by increasing interocular delay (when the delay exceeds the integration time, the inputs from the 2 eyes become uncorrelated). The amplitude of the disparity-selective response was a Gaussian function of interocular delay, with a mean of 16 ms (±5 ms, SD). Psychophysical measures of stereoacuity, in both monkey and human observers, showed a closely similar dependency on time, suggesting that temporal integration in V1 neurons is what determines psychophysical matching constraints over time. There was a slight but consistent asymmetry in the neuronal responses, as if the optimum stimulus is one in which the right stimulus leads by about 4 ms. Because all recordings were made in the left hemisphere, this probably reflects nasotemporal differences in conduction times; psychophysical data are compatible with this interpretation. In only a few neurons (5/72), interocular delay caused a change in the preferred disparity. Such tilted disparity/delay profiles have been invoked previously to explain depth perception in the stroboscopic version of the Pulfrich effect (and other variants). However, the great majority of the neurons did not show tilted disparity/delay profiles. This suggests that either the activity of these neurons is ignored when viewing Pulfrich stimuli, or that current theories relating neuronal properties to perception in the Pulfrich effect need to be reevaluated.

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Emergent orientation selectivity from random networks in mouse visual cortex

10.1101/285197 ◽

2018 ◽

Author(s):

J.J. Pattadkal ◽

G. Mato ◽

C. van Vreeswijk ◽

N. J. Priebe ◽

D. Hansel

Keyword(s):

Visual Cortex ◽

Calcium Imaging ◽

Receptive Fields ◽

Orientation Selectivity ◽

Random Networks ◽

Two Dimensional ◽

V1 Neurons ◽

Mouse Visual Cortex ◽

Whole Cell Recordings ◽

Random Connectivity

SummaryWe study the connectivity principles underlying the emergence of orientation selectivity in primary visual cortex (V1) of mammals lacking an orientation map. We present a computational model in which random connectivity gives rise to orientation selectivity that matches experimental observations. It predicts that mouse V1 neurons should exhibit intricate receptive fields in the two-dimensional frequency domain, causing shift in orientation preferences with spatial frequency. We find evidence for these features in mouse V1 using calcium imaging and intracellular whole cell recordings.

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