scholarly journals Extracellular recording of axonal spikes in the visual cortex

2021 ◽  
Author(s):  
Péter Barthó
Keyword(s):  
Visual Cortex ◽  
Extracellular Recording ◽  
Axonal Spikes

Corticofugal influences on visual responses in cat superior colliculus: The role of NMDA receptors

1996 ◽  
Vol 13 (4) ◽  
pp. 683-694 ◽  
Author(s):  
K. E. Binns ◽  
T. E. Salt
Keyword(s):  
Visual Cortex ◽  
Superior Colliculus ◽  
Nmda Receptors ◽  
Ganglion Cells ◽  
Extracellular Recording ◽  
Visual Responses ◽  
Directional Bias ◽  
Cortical Input ◽  
Visual Neurones

AbstractThe role of N-methyl-D-aspartate (NMDA) receptors in the mediation of cortical inputs to visual neurones in the superficial layers of the superior colliculus (SSC) has been investigated. Extracellular recording with iontophoresis in the SSC of cortically intact cats has demonstrated that visual responses of most neurones were reduced by iontophoretic application of the NMDA receptor antagonist D-2-amino-5-phosphonopentanoate (APS). Following inactivation of areas 17 and 18 of the visual cortex with topical lignocaine, the visual responses of 11, previously AP5-sensitive, neurones were no longer reduced by APS ejection. The cortical input is generally assumed to influence the directional responses of visual neurones in SSC. However, detailed study of the directional bias showed that the degree of directional tuning in SSC neurones was similar to that of retinal ganglion cells, as previously described by others. Moreover, inactivation of the visual cortex with topical lignocaine did not alter the directional bias of SSC neurones. Likewise, the directional bias of SSC neurones was not reduced by iontophoretic ejection of APS in the SSC. These data imply that NMDA receptors have an important role in mediating the cortical input to the SSC. However, cortical input does not appear to be responsible for conferring directional bias upon SSC neurones' visual responsiveness.

scholarly journals Closing the Critical Period Is Required for the Maturation of Binocular Integration in Mouse Primary Visual Cortex

2021 ◽  
Vol 15 ◽  
Author(s):  
Jiangping Chan ◽  
Xiangwen Hao ◽  
Qiong Liu ◽  
Jianhua Cang ◽  
Yu Gu
Keyword(s):  
Visual Cortex ◽  
Mouse Model ◽  
Primary Visual Cortex ◽  
Depth Perception ◽  
Critical Period ◽  
Visual Experience ◽  
Extracellular Recording ◽  
Molecular Assay ◽  
Binocular Matching

Binocular matching of orientation preference between the two eyes is a common form of binocular integration that is regarded as the basis for stereopsis. How critical period plasticity enables binocular matching under the guidance of normal visual experience has not been fully demonstrated. To investigate how critical period closure affects the binocular matching, a critical period prolonged mouse model was constructed through the administration of bumetanide, an NKCC1 transporter antagonist. Using acute in vivo extracellular recording and molecular assay, we revealed that binocular matching was transiently disrupted due to heightened plasticity after the normal critical period, together with an increase in the density of spines and synapses, and the upregulation of GluA1 expression. Diazepam (DZ)/[(R, S)-3-(2-carboxypiperazin-4-yl) propyl-1-phosphonic acid (CPP)] could reclose the extended critical period, and rescue the deficits in binocular matching. Furthermore, the extended critical period, alone, with normal visual experience is sufficient for the completion of binocular matching in amblyopic mice. Similarly, prolonging the critical period into adulthood by knocking out Nogo-66 receptor can prevent the normal maturation of binocular matching and depth perception. These results suggest that maintaining an optimal plasticity level during adolescence is most beneficial for the systemic maturation. Extending the critical period provides new clues for the maturation of binocular vision and may have critical implications for the treatment of amblyopia.

scholarly journals High-Amplitude Positive Spikes Recorded Extracellularly in Cat Visual Cortex

2009 ◽  
Vol 102 (6) ◽  
pp. 3340-3351 ◽  
Author(s):  
Carl Gold ◽  
Cyrille C. Girardin ◽  
Kevan A. C. Martin ◽  
Christof Koch
Keyword(s):  
Visual Cortex ◽  
Pyramidal Neurons ◽  
Extracellular Recording ◽  
Mean Amplitude ◽  
High Amplitude ◽  
Dominant Negative ◽  
Generation Process ◽  
Biophysical Models ◽  
Negative Peak ◽  
Positive Peak

We simulated the shape and amplitude of extracellular action potentials (APs or “spikes”) using biophysical models based on detailed reconstructions of single neurons from the cat's visual cortex. We compared these predictions with spikes recorded from the cat's primary visual cortex under a standard protocol. The experimental data were derived from a large number of neurons throughout all layers. The majority of spikes were biphasic, with a dominant negative peak (mean amplitude, −0.11 mV), whereas a minority of APs had a dominant positive peak of +0.54-mV mean amplitude, with a maximum of +1.5 mV. The largest positive amplitude spikes were recorded in layer 5. The simulations demonstrated that a pyramidal neuron under known biophysical conditions may generate a negative peak with amplitude up to −1.5 mV, but that the amplitude of the positive peak may be at most 0.5 mV. We confirmed that spikes with large positive peaks were not produced by juxtacellular patch recordings. We conclude that there is a significant gap in our present understanding of either the spike-generation process in pyramidal neurons, the biophysics of extracellular recording, or both.

Are primate lateral geniculate nucleus (LGN) cells really sensitive to orientation or direction?

2002 ◽  
Vol 19 (1) ◽  
pp. 97-108 ◽  
Author(s):  
XIANGMIN XU ◽  
JENNIFER ICHIDA ◽  
YURI SHOSTAK ◽  
A.B. BONDS ◽  
VIVIEN A. CASAGRANDE
Keyword(s):  
Visual Cortex ◽  
Lateral Geniculate Nucleus ◽  
Cortical Cell ◽  
Extracellular Recording ◽  
Orientation Tuning ◽  
Cell Orientation ◽  
Lateral Geniculate ◽  
Spatial Frequencies ◽  
Degree Of Orientation ◽  
Direction Sensitivity

There is considerable controversy over the existence of orientation and direction sensitivity in lateral geniculate nucleus (LGN) neurons. Claims for the existence of these properties often were based upon data from cells tested well beyond their peak spatial frequencies. The goals of the present study were to examine the degree of orientation and direction sensitivity of LGN cells when tested at their peak spatial and temporal frequencies and to compare the tuning properties of these subcortical neurons with those of visual cortex. For this investigation, we used conventional extracellular recording to study orientation and direction sensitivities of owl monkey LGN cells by stimulating cells with drifting sinusoidal gratings at peak temporal frequencies, peak or higher spatial frequencies, and moderate contrast. A total of 110 LGN cells (32 koniocellular cells, 34 magnocellular cells, and 44 parvocellular cells) with eccentricities ranging from 2.6 deg to 27.5 deg were examined. Using the peak spatial and temporal frequencies for each cell, 41.8% of the LGN cells were found to be sensitive to orientation and 19.1% were direction sensitive. The degree of bias for orientation and direction did not vary with eccentricity or with cell class. Orientation sensitivity did, however, increase, and in some cases orientation preferences changed, at higher spatial frequencies. Increasing spatial frequency had no consistent effect on direction sensitivity. Compared to cortical cell orientation tuning, the prevalence and strength of LGN cell orientation and direction sensitivity are weak. Nevertheless, the high percentage of LGN cells sensitive to orientation even at peak spatial and temporal frequencies reinforces the view that subcortical biases could, in combination with activity-dependent cortical mechanisms and/or cortical inhibitory mechanisms, account for the much narrower orientation and direction tuning seen in visual cortex.

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