Long-range horizontal connections and their role in cortical reorganization revealed by optical recording of cat primary visual cortex

Das, Aniruddha; Gilbert, Charles D.

doi:10.1038/375780a0

Cited by 418 publications

(269 citation statements)

References 23 publications

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“…Because the optical images generated here were made with stationary stimuli, they moreover represent the finest resolution pictures of the minimal spread of activity across the surface of the cortex (the cortical point-spread function; refs. [30][31][32]. These images correlate well with similar images we published previously (15).…”

Section: Discussionsupporting

confidence: 82%

The role of spatiotemporal edges in visibility and visual masking

Macknik

Martínez-Conde

Haglund

2000

Proc. Natl. Acad. Sci. U.S.A.

107

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What parts of a visual stimulus produce the greatest neural signal? Previous studies have explored this question and found that the onset of a stimulus's edge is what excites early visual neurons most strongly. The role of inhibition at the edges of stimuli has remained less clear, however, and the importance of neural responses associated with the termination of stimuli has only recently been examined. Understanding all of these spatiotemporal parameters (the excitation and inhibition evoked by the stimulus's onset and termination, as well as its spatial edges) is crucial if we are to develop a general principle concerning the relationship between neural signals and the parts of the stimulus that generate them. Here, we use visual masking illusions to explore this issue, in combination with human psychophysics, awake behaving primate neurophysiology in the lateral geniculate nucleus of the thalamus, and optical recording in the primary visual cortex of anesthetized monkeys. The edges of the stimulus, rather than its interior, generate the strongest excitatory and inhibitory responses both perceptually and physiologically. These edges can be imaged directly by using optical recording techniques. Excitation and inhibition are moreover most powerful when the stimulus turns both on and off (what might be thought of as the stimulus's temporal edges). We thus conclude that there is a general principle that relates the generation of neural signals (excitatory and inhibitory) to the spatiotemporal edges of stimuli in the early visual system.

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Section: Discussionsupporting

confidence: 82%

The role of spatiotemporal edges in visibility and visual masking

Macknik

Martínez-Conde

Haglund

2000

Proc. Natl. Acad. Sci. U.S.A.

107

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“…In the future, these capacities might provide a powerful approach to study cortical reorganization processes (70,71) of the functional neuronal architecture induced by TMSbased plasticity and learning protocols. Heart rate, intratracheal pressure, exhaled CO 2 , and body temperature were monitored.…”

Section: Discussionmentioning

confidence: 99%

Voltage-sensitive dye imaging of transcranial magnetic stimulation-induced intracortical dynamics

Kozyrev

Eysel

Jancke

2014

Proc. Natl. Acad. Sci. U.S.A.

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Transcranial magnetic stimulation (TMS) is widely used in clinical interventions and basic neuroscience. Additionally, it has become a powerful tool to drive plastic changes in neuronal networks. However, highly resolved recordings of the immediate TMS effects have remained scarce, because existing recording techniques are limited in spatial or temporal resolution or are interfered with by the strong TMS-induced electric field. To circumvent these constraints, we performed optical imaging with voltage-sensitive dye (VSD) in an animal experimental setting using anaesthetized cats. The dye signals reflect gradual changes in the cells' membrane potential across several square millimeters of cortical tissue, thus enabling direct visualization of TMS-induced neuronal population dynamics. After application of a single TMS pulse across visual cortex, brief focal activation was immediately followed by synchronous suppression of a large pool of neurons. With consecutive magnetic pulses (10 Hz), widespread activity within this "basin of suppression" increased stepwise to suprathreshold levels and spontaneous activity was enhanced. Visual stimulation after repetitive TMS revealed long-term potentiation of evoked activity. Furthermore, loss of the "deceleration-acceleration" notch during the rising phase of the response, as a signature of fast intracortical inhibition detectable with VSD imaging, indicated weakened inhibition as an important driving force of increasing cortical excitability. In summary, our data show that high-frequency TMS changes the balance between excitation and inhibition in favor of an excitatory cortical state. VSD imaging may thus be a promising technique to trace TMS-induced changes in excitability and resulting plastic processes across cortical maps with high spatial and temporal resolutions. (1) (TMS) has become a frequently used method for noninvasive diagnostics, therapeutic treatment, and intervention for neurorehabilitation of neurological disorders (2-8). Additionally, TMS has proved a valuable tool in basic brain research as its perturbative effects allow area-selective manipulation of immediate cortical function (9-11), as well as its long-lasting alteration through plasticity and learning protocols (12, 13). However, direct measurements of the TMS-induced cortical dynamics at highly resolved spatiotemporal scales are missing because "online approaches" (14), using modern neuroimaging techniques such as functional MRI (fMRI) (15-18), magnetoencephalography (19), EEG (20), and near-infrared (21) or intrinsic optical imaging (22), are limited in either spatial or temporal resolutions or in both.Here we overcame these limitations, using optical imaging with voltage-sensitive dyes (VSD), which exploits the dye's property to transduce gradual changes in voltage across neuronal membranes into fluorescent light signals. In contrast to imaging methods applicable in humans, this method is invasive but allows avoiding the commonly experienced contamination of signals by artifacts due to the strong ...

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“…This lability even includes the ability to convert modulatory synapses to driving synapses if the original RF input is removed for long enough (e.g. Das and Gilbert, 1995). To be useful, however, such change requires appropriate modifications at the sites to which the cell projects.…”

Section: The Selective Sensitivity Specified By Driving Inputs Is Labilementioning

confidence: 99%

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

Phillips

Clark

Silverstein

2015

Neuroscience & Biobehavioral Reviews

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A broad neuron-centric conception of contextual modulation is reviewed and re-assessed in the light of recent neurobiological studies of amplification, suppression, and synchronization. Behavioural and computational studies of perceptual and higher cognitive functions that depend on these processes are outlined, and evidence that those functions and their neuronal mechanisms are impaired in schizophrenia is summarized. Finally, we compare and assess the long-term biological functions of contextual modulation at the level of computational theory as formalized by the theories of coherent infomax and free energy reduction. We conclude that those theories, together with the many empirical findings reviewed, show how contextual modulation at the neuronal level enables the cortex to flexibly adapt the use of its knowledge to current circumstances by amplifying and grouping relevant activities and by suppressing irrelevant activities.

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Long-range horizontal connections and their role in cortical reorganization revealed by optical recording of cat primary visual cortex

Cited by 418 publications

References 23 publications

The role of spatiotemporal edges in visibility and visual masking

The role of spatiotemporal edges in visibility and visual masking

Voltage-sensitive dye imaging of transcranial magnetic stimulation-induced intracortical dynamics

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

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