Recruitment of Local Inhibitory Networks by Horizontal Connections in Layer 2/3 of Ferret Visual Cortex

2003 ◽  
Vol 89 (1) ◽  
pp. 501-512 ◽  
Author(s):  
Thomas R. Tucker ◽  
Lawrence C. Katz
Keyword(s):  
Visual Cortex ◽  
Cortical Layer ◽  
Strong Inhibition ◽  
Nonlinear Responses ◽  
Horizontal Connections ◽  
Co Activation ◽  
Layer 2 ◽  
Linear Integration ◽  
Stimulation Of ◽  
Inhibitory Networks

To investigate how neurons in cortical layer 2/3 integrate horizontal inputs arising from widely distributed sites, we combined intracellular recording and voltage-sensitive dye imaging to visualize the spatiotemporal dynamics of neuronal activity evoked by electrical stimulation of multiple sites in visual cortex. Individual stimuli evoked characteristic patterns of optical activity, while delivering stimuli at multiple sites generated interacting patterns in the regions of overlap. We observed that neurons in overlapping regions received convergent horizontal activation that generated nonlinear responses due to the emergence of large inhibitory potentials. The results indicate that co-activation of multiple sets of horizontal connections recruit strong inhibition from local inhibitory networks, causing marked deviations from simple linear integration.

Effect of electrical stimulation of locus coeruleus on the activity of neurons in the cat visual cortex

1989 ◽  
Vol 62 (4) ◽  
pp. 946-958 ◽  
Author(s):  
H. Sato ◽  
K. Fox ◽  
N. W. Daw
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Adrenergic Receptor ◽  
Suppressive Effect ◽  
Cortical Layer ◽  
Facilitatory Effect ◽  
Receptor Antagonists ◽  
Complex Cells ◽  
Beta Receptors ◽  
Stimulation Of

1. We studied the effect of electrically stimulating the locus coeruleus (LC) and iontophoresing noradrenergic antagonists on visual responses and spontaneous activity of individual cells in the cat primary visual cortex. 2. A bilateral projection from LC to visual cortex was demonstrated anatomically, by retrograde labeling using horseradish peroxidase. Where electrical stimulation of both ipsilateral and contralateral LC affected a cortical neuron, the effect induced by stimulating each side was similar. 3. One hundred and two cells were recorded in area 17: 52% of them had their activity suppressed and 36% had their activity facilitated by LC stimulation. The suppressive effect was predominant in cortical layers II + III and IV, whereas most cells in layer V and one-half of the cells in layer VI were facilitated by LC stimulation. This suggests that LC neurons innervate each cortical layer in a different manner. 4. Simple and complex cells were equally sensitive to LC stimulation. For simple cells, the suppressive effect of LC stimulation was dominant throughout all layers. For complex cells, the suppressive effect was dominant in layers II + III and IV, whereas the facilitatory effect was dominant in layers V and VI. 5. The suppressive effect of LC stimulation was blocked by iontophoretic application of beta-adrenergic receptor antagonists and the facilitatory effect was blocked by either alpha- or beta-adrenergic receptor antagonists. 6. Nonselective alpha-, and selective alpha 1- and alpha 2-receptor antagonists suppressed visual and spontaneous activity in almost all neurons tested, suggesting that these receptors are either facilitatory at a postsynaptic site or inhibitory at a site presynaptic to an inhibitory synapse in the visual cortex. 7. beta-Receptor antagonists facilitated activity in 45% and suppressed activity in 36% of the cells tested, suggesting there are both suppressive and facilitatory types of beta-receptors. 8. The effectiveness of alpha- and beta-antagonists on the activity of neurons without LC stimulation also suggested that spontaneously released noradrenaline activated noradrenergic receptors in the visual cortex even in the anesthetized and paralyzed cat. 9. In most cells tested, both alpha- and beta-receptor antagonists exerted effects on single neurons suggesting that endogenous noradrenaline acts on both alpha- and beta-receptors on the same cell. 10. The activation of LC did not improve the signal- (visual response)to-noise (spontaneous discharge) ratio of neurons in the visual cortex. 11. LC seemed to control the activity of each cortical layer differently, by activating different kinds of noradrenergic receptors in different layers.

Layer-specific serotonergic facilitation of IPSC in layer 2/3 pyramidal neurons of the visual cortex

2012 ◽  
Vol 107 (1) ◽  
pp. 407-416 ◽  
Author(s):  
Hyun-Jong Jang ◽  
Kwang-Hyun Cho ◽  
Sung-Won Park ◽  
Myung-Jun Kim ◽  
Shin Hee Yoon ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Visual Cortex ◽  
Pyramidal Neurons ◽  
Inhibitory Influence ◽  
Inhibitory Transmission ◽  
Layer 2 ◽  
Specific Manner ◽  
Intracellular Ca ◽  
Stimulation Of

Serotonin (5-hydroxytryptamine, 5-HT) inhibits the induction of long-term synaptic plasticity in layer 2/3 of the visual cortex at the end of its critical period in rats. However, the cellular and molecular mechanisms remain unclear. Since inhibitory influence is crucial in the induction of synaptic plasticity, the effect of 5-HT on inhibitory transmission was investigated in layer 2/3 pyramidal neurons of the primary visual cortex. The amplitude of inhibitory postsynaptic current (IPSC), but not excitatory postsynaptic current, evoked by stimulation of the underlying layer 4, was increased by ∼20% with a bath application of 5-HT. The amplitude of miniature IPSC was also increased by the application of 5-HT, while the paired-pulse ratio was not changed. The facilitating effect of 5-HT on IPSC was mediated by the activation of 5-HT2 receptors. An increase in intracellular Ca2+ via release from inositol 1,4,5-trisphosphate (IP3)-sensitive stores, which was confirmed by confocal Ca2+ imaging, and activation of Ca2+/calmodulin-dependent kinase II (CaMKII) were involved in the facilitation of IPSC by 5-HT. However, 5-HT failed to facilitate IPSC evoked by the stimulation of layer 1. These results suggest that activation of 5-HT2 receptors releases intracellular Ca2+ via IP3-sensitive stores, which facilitates GABAAergic transmission via the activation of CaMKII in layer 2/3 pyramidal neurons of the visual cortex in a layer-specific manner. Thus facilitation of inhibitory transmission by 5-HT might be involved in regulating the information flow and the induction of long-term synaptic plasticity, in a pathway-specific manner.

Spatiotemporal Patterns of Excitation and Inhibition Evoked by the Horizontal Network in Layer 2/3 of Ferret Visual Cortex

2003 ◽  
Vol 89 (1) ◽  
pp. 488-500 ◽  
Author(s):  
Thomas R. Tucker ◽  
Lawrence C. Katz
Keyword(s):  
Visual Cortex ◽  
Temporal Distribution ◽  
Population Based ◽  
Spatiotemporal Patterns ◽  
Horizontal Connections ◽  
Physiological Properties ◽  
Layer 2 ◽  
Diffuse Zone ◽  
Voltage Sensitive Dyes ◽  
Horizontal Network

The horizontal network in visual cortex layer 2/3 is implicated in numerous psychophysical and physiological properties. To investigate the spatial and temporal distribution of excitation and inhibition evoked by this network, we used voltage-sensitive dyes to image the responses to focal electrical stimulation in tangential slices of ferret visual cortex layer 2/3. The resulting optical patterns included a diffuse zone of activation near the stimulation site and numerous ovoid domains throughout the slice. In contrast to the fixed anatomy of the horizontal connections, substantial shifts in both space and time were evident in the distribution of population-based neuronal activity during stimulus trains. Both of these shifts relied on inhibitory synaptic potentials, suggesting that inhibition driven by horizontal connections sculpts the distribution of activity in this cortical network.

scholarly journals The influence of cortical depth on neuronal responses in mouse visual cortex

2018 ◽  
Author(s):  
Philip O’Herron ◽  
John Woodward ◽  
Prakash Kara
Keyword(s):  
Visual Cortex ◽  
Neuronal Response ◽  
Superficial Layer ◽  
Cortical Layer ◽  
Contrast Imaging ◽  
Response Properties ◽  
Layer 2 ◽  
Layer 4 ◽  
Thalamic Projections ◽  
Mouse Visual Cortex

AbstractWith the advent of two-photon imaging as a tool for systems neuroscience, the mouse has become a preeminent model system for studying sensory processing. One notable difference that has been found however, between mice and traditional model species like cats and primates is the responsiveness of the cortex. In the primary visual cortex of cats and primates, nearly all neurons respond to simple visual stimuli like drifting gratings. In contrast, imaging studies in mice consistently find that only around half of the neurons respond to such stimuli. Here we show that visual responsiveness is strongly dependent on the cortical depth of neurons. Moving from superficial layer 2 down to layer 4, the percentage of responsive neurons increases dramatically, ultimately reaching levels similar to what is seen in other species. Over this span of cortical depth, neuronal response amplitude also increases and orientation selectivity moderately decreases. These depth dependent response properties may be explained by the distribution of thalamic inputs in mouse V1. Unlike in cats and primates where thalamic projections to the granular layer are constrained to layer 4, in mice they spread up into layer 2/3, qualitatively matching the distribution of response properties we see. These results show that the analysis of neural response properties must take into consideration not only the overall cortical lamina boundaries but also the depth of recorded neurons within each cortical layer. Furthermore, the inability to drive the majority of neurons in superficial layer 2/3 of mouse V1 with grating stimuli indicates that there may be fundamental differences in the role of V1 between rodents and other mammals.

scholarly journals Comparison of Spatial Summation Properties of Neurons in Macaque V1 and V2

2009 ◽  
Vol 102 (4) ◽  
pp. 2069-2083 ◽  
Author(s):  
S. Shushruth ◽  
Jennifer M. Ichida ◽  
Jonathan B. Levitt ◽  
Alessandra Angelucci
Keyword(s):  
Visual Cortex ◽  
Spatial Summation ◽  
Spatial Integration ◽  
Surround Suppression ◽  
Low Contrast ◽  
Rf Components ◽  
Horizontal Connections ◽  
Underlying Mechanisms ◽  
Feedback Connections ◽  
Stimulation Of

In visual cortex, responses to stimulation of the receptive field (RF) are modulated by simultaneous stimulation of the RF surround. The mechanisms for surround modulation remain unidentified. We previously proposed that in the primary visual cortex (V1), near surround modulation is mediated by geniculocortical and horizontal connections and far surround modulation by interareal feedback connections. To understand spatial integration in the secondary visual cortex (V2) and its underlying circuitry, we have characterized spatial summation in different V2 layers and stripe compartments and compared it to that in V1. We used grating stimuli in circular and annular apertures of different sizes to estimate the extent and sensitivity of RF and surround components in V1 and V2. V2 RFs and surrounds were twice as large as those in V1. As in V1, V2 RFs doubled in size when measured at low contrast. In both V1 and V2, surrounds were about fivefold the size of the RF and the far surround could exceed 12.5° in radius, averaging 5.5° in V1 and 9.2° in V2. The strength of surround suppression was similar in both areas. Thus although differing in spatial scale, the interactions among RF components are similar in V1 and V2, suggesting similar underlying mechanisms. As in V1, the extent of V2 horizontal connections matches that of the RF center, but is much smaller than the largest far surrounds, which likely derive from interareal feedback. In V2, we found no laminar or stripe differences in size and magnitude of surround suppression, suggesting conservation across stripes of the basic circuit for surround modulation.

scholarly journals Excitatory and inhibitory L2/3 neurons in mouse primary visual cortex are balanced in their input connectivity

2020 ◽  
Author(s):  
Alexander P.Y. Brown ◽  
Lee Cossell ◽  
Troy W. Margrie
Keyword(s):  
Visual Cortex ◽  
Long Range ◽  
Primary Visual Cortex ◽  
Analytical Approach ◽  
Neural Circuits ◽  
Brain Regions ◽  
Inhibitory Neurons ◽  
Hierarchical Segmentation ◽  
Layer 2 ◽  
Inhibitory Networks

AbstractQuantitatively characterising brain-wide connectivity of neural circuits is of vital importance in understanding the function of the mammalian cortex. Here we have designed an analytical approach to examine data from hierarchical segmentation ontologies, and applied it in the comparison of long-range presynaptic connectivity onto excitatory and inhibitory neurons in layer 2/3 (L2/3) of mouse primary visual cortex (V1). We find that long-range connections onto these two general cell classes in L2/3 originate from highly similar brain regions, and in similar proportions, when compared to input to layer 6. These anatomical data suggest that distal information received by excitatory and inhibitory networks is highly homogenous in L2/3.

Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Adverse Events ◽  
Clinical Intervention ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Serious Adverse Events ◽  
Stimulation Parameters ◽  
The Right ◽  
Visual Cortical ◽  
Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

scholarly journals Development of Horizontal Projections in Layer 2/3 of Ferret Visual Cortex

1996 ◽  
Vol 6 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Jeremy C. Durack ◽  
Lawrence C. Katz
Keyword(s):  
Visual Cortex ◽  
Layer 2

scholarly journals Electrical Stimulation of the Human Visual Cortex Preliminary Report

1974 ◽  
Vol 1 (4) ◽  
pp. 236-238 ◽  
Author(s):  
Andrew Talalla ◽  
Leo Bullara ◽  
Robert Pudenz
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Feasibility Study ◽  
Preliminary Report ◽  
Visual Prosthesis ◽  
Human Visual Cortex ◽  
Stimulation Of

SUMMARY:A feasibility study for the development of a human visual prosthesis has led several workers to observe the effects of electrical stimulation of the human visual cortex. Experience with such stimulations of three normal-sighted patients is reported. The results confirm some of the findings of other workers, but do not show that multiple phosphenes were experienced by our patients, using strictly limited parameters of stimulation.

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