Effect of longer periods of dark rearing on NMDA receptors in cat visual cortex

1994 ◽  
Vol 72 (3) ◽  
pp. 1220-1226 ◽  
Author(s):  
D. Czepita ◽  
S. N. Reid ◽  
N. W. Daw
Keyword(s):  
Visual Cortex ◽  
Nmda Receptor ◽  
Firing Rate ◽  
Spontaneous Activity ◽  
Visual Response ◽  
Visual Responses ◽  
Level Of Activity ◽  
Direction Of Movement ◽  
Excitatory Drive ◽  
Dark Rearing

1. Cats were reared in the dark to 3, 5, and 11 mo. We studied the N-methyl-D-aspartate (NMDA) receptor contribution to the visual response in the cortex, defined as the percentage reduction in visual response after application of 2-amino-5-phosphonovaleric acid (APV). We also studied the firing rate in response to the optimal visual stimulus and the spontaneous activity. We made comparisons of all these properties between light-reared and dark-reared animals. 2. The NMDA receptor contribution to the visual response in layers IV, V, and VI of dark-reared animals was substantially above that in light-reared animals at all ages tested. 3. The specificity of receptive field properties in dark-reared animals showed some degeneration between 6 wk and 3 mo of age. At > or = 3 mo, almost no cells were specific for orientation and direction of movement. 4. Firing rate was lower in dark-reared animals at all ages, suggesting a decrease in excitatory drive to the visual cortex. 5. Spontaneous activity was equal in dark- and light-reared animals, suggesting that the overall level of activity (including visual responses as well as spontaneous activity) in light-reared animals is higher than in dark-reared animals. This should tend to upregulate glutamate receptors in general in dark-reared animals.

Effect of passive eye movement on retinogeniculate transmission in the cat

1990 ◽  
Vol 63 (3) ◽  
pp. 523-538 ◽  
Author(s):  
R. Lal ◽  
M. J. Friedlander
Keyword(s):  
Firing Rate ◽  
Spontaneous Activity ◽  
Eye Movement ◽  
Visual Stimulus ◽  
Action Potentials ◽  
Visual Stimuli ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Visual Responses ◽  
Movement Effect

1. The nature and time window of interaction between passive phasic eye movement signals and visual stimuli were studied for dorsal lateral geniculate nucleus (LGNd) neurons in the cat. Extracellular recordings were made from single neurons in layer A of the left LGNd of anesthetized paralyzed cats in response to a normalized visual stimulus presented to the right eye at each of several times of movement of the left eye. The left eye was moved passively at a fixed amplitude and velocity while varying the movement onset time with respect to the visual stimulus onset in a randomized and interleaved fashion. Visual stimuli consisted of square-wave modulated circular spots of appropriate contrast, sign, and size to elicit an optimal excitatory response when placed in the neurons' receptive-field (RF) center. 2. Interactions were analyzed for 78 neurons (33 X-neurons, 43 Y-neurons, and 2 physiologically unclassified neurons) on 25-65 trials of identical visual stimuli for each of eight times of eye movement. 3. Sixty percent (47/78) of the neurons tested had a significant eye movement effect (ANOVA, P less than 0.05) on some aspect of their visual response. Of these 47 neurons, 42 (89%) had a significant (P less than 0.05) effect of an appropriately timed eye movement on the number of action potentials, 36 (77%) had a significant effect on the mean peak firing rate, and 31 (66%) were significantly affected as evaluated by both criteria. 4. The eye movement effect on the neurons' visual responses was primarily facilitatory. Facilitation was observed for 37 (79%) of the affected neurons. For 25 of these 37 neurons (68%), the facilitation was significant (P less than 0.05) as evaluated by both criteria (number of action potentials and mean peak firing rate). Ten (21%) of the affected neurons had their visual response significantly inhibited (P less than 0.05). 5. Sixty percent (46/78) of the neurons were tested for the effect of eye movement on both visually elicited activity (visual stimulus contrast = 2 times threshold) and spontaneous activity (contrast = 0). Eye movement significantly affected the visual response of 23 (50%) of these neurons. However, spontaneous activity was significantly affected for only nine (20%) of these neurons. The interaction of the eye movement and visual signals was nonlinear. 6. Nine of 12 neurons (75%) tested had a directionally selective effect of eye movement on the visual response, with most (8/9) preferring the temporal ward direction.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Serotonergic Modulation of Orientation Tuning of Neurons in Primary Visual Cortex of Anesthetized Mice

2021 ◽  
Author(s):  
Sareh Rostami ◽  
◽  
Amin Asgharzadeh Alvar ◽  
Parviz Ghaderi ◽  
Leila Dargahi ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Firing Rate ◽  
Primary Visual Cortex ◽  
Serotonergic System ◽  
Orientation Tuning ◽  
Visual Response ◽  
Visual Responses ◽  
Patch Clamp Recording ◽  
Serotonergic Modulation

Introduction: Sensory processing is profoundly regulated by brain neuromodulatory systems. One of the main neuromodulators is serotonin which influences higher cognitive functions such as different aspects of perceptual processing. So, malfunction in the serotonergic system may lead to visual illusion in psychiatric disorders such as autism and schizophrenia. In this work, we examined the serotonergic modulation of visual responses of neurons to stimulus orientation in the primary visual cortex. Methods: Eight-weeks old naive mice were anesthetized and craniotomy was done on the region of interest in primary visual cortex. Spontaneous and visual-evoked activities of neurons were recorded before and during the electrical stimulation of dorsal raphe nucleus using in vivo whole-cell patch-clamp recording. Square-wave grating of 12 orientations was presented. Data was analyzed and Wilcoxon signed-rank test, used in order to compare the data of two conditions that belong to the same neurons, with or without electrical stimulation. Results: The serotonergic system changed orientation tuning of about 60 % recorded neurons by decreasing the mean firing rate in two independent visual response components: gain and baseline response. It also increased mean firing rate in a small number of neurons (about 20%). Beyond that, it left the preferred orientation and sensitivity of neurons unchanged. Conclusion: However, serotonergic modulation showed a bi-directional effect; it seems to cause predominately divisive and subtractive decreases in the visual responses of the neurons in the primary visual cortex that can modify the balance between internal and external sensory signals and result in disorders.

Dependence of retinogeniculate transmission in cat on NMDA receptors

1990 ◽  
Vol 63 (2) ◽  
pp. 347-355 ◽  
Author(s):  
A. M. Sillito ◽  
P. C. Murphy ◽  
T. E. Salt ◽  
C. I. Moody
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Visual Responses ◽  
Receptor Agonists ◽  
Selective Blockade ◽  
X And Y Cells ◽  
X 24 ◽  
Y Cells

1. We have examined the possibility that N-methyl-D-aspartate (NMDA) receptors may be involved in the visual response of relay cells in the cat dorsal lateral geniculate nucleus (dLGN). The selective NMDA receptor antagonists D-2-amino-5-phosphonovalerate (APV) and 3-[(+/-)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid (CPP) have been iontophoretically applied to X and Y cells in the dLGN and their effects on the visual response to a light spot flashed within the receptive field center determined. 2. The antagonist effects were assessed at ejection current levels producing a selective blockade of the responses to iontophoretically applied NMDA with respect to those elicited by the non-NMDA receptor agonists quisqualate and kainate. These selective effects were determined in an experimental paradigm where the visual response and responses to NMDA and the non-NMDA receptor agonists were compared in the same test run. The data refer to a total population of 52 cells (28 X, 24 Y). 3. Application of APV abolished or greatly reduced the visual responses of both X and Y cells. The mean percentage reduction in the visual response for the X cells studied was 59 +/- 10% (SE; n = 7) and for the Y cells 66 +/- 8% (SE; n = 11). Both the early onset transient and the sustained component of the visual response to the flashed stimulus were equally affected. 4. The antagonist CPP produced a similar pattern of effect to APV, substantially reducing or abolishing the visual response in both X and Y cells.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of varying stimulus intensity on NMDA-receptor activity in cat visual cortex

1990 ◽  
Vol 64 (5) ◽  
pp. 1413-1428 ◽  
Author(s):  
K. Fox ◽  
H. Sato ◽  
N. Daw
Keyword(s):  
Visual Cortex ◽  
Nmda Receptor ◽  
Nmda Receptors ◽  
Receptor Activation ◽  
Visual Response ◽  
Background Luminance ◽  
Stimulus Contrast ◽  
Cat Visual Cortex ◽  
Low Levels ◽  
Nmda Receptor Activation

1. A study was made of the relative contribution of N-methyl-D-aspartate (NMDA) and non-NMDA receptors to the visual responses of cells in different layers of the cat visual cortex at different levels of excitatory drive (which was varied by altering the stimulus contrast). 2. Receptive fields were mapped for 121 cells in area 17 of cat cortex. Cells were characterized to determine the optimal visual stimulus, the brightness of which was then varied relative to background luminance to construct a contrast-response (C-R) curve for each cell. Curves were made during control conditions and during application of agonists (NMDA and quisqualate) and/or antagonists [(D)-2-amino-5-phosphonovaleric acid (D-APV) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)] to examine the excitatory amino acid components of the visual response. 3. Threshold responses were obtained with stimuli between 1/60 and 1.8 X background luminance. The cell response, measured by firing rate, was linearly related to stimulus contrast over 1-2 decades and saturated at higher contrasts. 4. Application of APV reduced the slope of the linear portion of the C-R curve for cells located in layers II and III (average reduction, 59% of control). APV did not decrease the threshold to stimulation. The "just suprathreshold" responses to stimulation were reduced by the same proportion as the saturation responses for individual cells. The principal effect was therefore to reduce the gain of the C-R curve in these layers. 5. Application of APV reduced the spontaneous activity of cells located in layers IV, V, and VI with little if any effect on the gain of the C-R curve. This suggests a tonic background level of NMDA-receptor activation in these layers, which is not directly related to the visual response. 6. Low levels of NMDA increased the gain of the C-R curve in layers II/III and V/VI. On the other hand, low levels of quisqualate increased the overall level of firing without affecting the gain of the C-R curve. NMDA did not increase the gain of the curve in layer IV. 7. These experiments show that visual stimuli that produce just suprathreshold responses activate NMDA receptors. The degree of activation is proportionally the same for small responses and large responses for an individual cell. Rather than finding a threshold for NMDA-receptor activation, a continuous range of NMDA-receptor influence was observed over the entire response range.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the Group II Metabotropic Glutamate Agonist, 2R,4R-APDC, Varies With Age, Layer, and Visual Experience in the Visual Cortex

1999 ◽  
Vol 82 (1) ◽  
pp. 86-93 ◽  
Author(s):  
C. J. Beaver ◽  
Q.-H. Ji ◽  
N. W. Daw
Keyword(s):  
Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Stimulation ◽  
Ocular Dominance ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Layer 4 ◽  
Group Ii ◽  
Dark Rearing

Group II metabotropic glutamate receptors (mGluR 2/3) are distributed differentially across the layers of cat visual cortex, and this distribution varies with age. At 3–4 wk, mGluR 2/3 receptor immunoreactivity is present in all layers. By 6–8 wk of age, it is still present in extragranular layers (2, 3, 5, and 6) but has disappeared from layer 4, and dark-rearing postpones the disappearance of Group II receptors from layer 4. We examined the physiological effects of Group II activation, to see if these effects varied similarly. The responses of single neurons in cat primary visual cortex were recorded to visual stimulation, then the effect of iontophoresis of 2R,4R-4 aminopyrrolidine-2,4-decarboxylate (2R,4R-APDC), a Group II specific agonist, was observed in animals between 3 wk and adulthood. The effect of 2R,4R-APDC was generally suppressive, reducing both the visual response and spontaneous activity of single neurons. The developmental changes were in agreement with the immunohistochemical results: 2R,4R-APDC had effects on cells in all layers in animals of 3–4 wk but not in layer 4 of animals >6 wk old. Moreover, the effect of 2R,4R-APDC was reduced in the cortex of older animals (>22 wk). Dark-rearing animals to 47–54 days maintained the effects of 2R,4R-APDC in layer 4. The disappearance of Group II mGluRs from layer 4 between 3 and 6 wk of age is correlated with the segregation of ocular dominance columns in that layer, raising the possibility that mGluRs 2/3 are involved in this process.

Activation of metabotropic glutamate receptors has different effects in different layers of cat visual cortex

1997 ◽  
Vol 14 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Silvia N.M. Reid ◽  
Nigel W. Daw
Keyword(s):  
Visual Cortex ◽  
Dicarboxylic Acid ◽  
Glutamate Receptors ◽  
Spontaneous Activity ◽  
Primary Visual Cortex ◽  
Metabotropic Glutamate Receptors ◽  
Visual Response ◽  
Single Neurons ◽  
Metabotropic Glutamate ◽  
Cat Visual Cortex

AbstractSingle neurons were recorded in cat primary visual cortex, and the effect of iontophoresis of the metabotropic glutamate agonist 1S,3R-aminocyclopentane-1.3-dicarboxylic acid (ACPD) was observed. In nearly all cases (41/43), ACPD reduced the visual response. In some cases ACPD also reduced spontaneous activity (24/43), and in other cases ACPD increased spontaneous activity (18/43). Increases were generally seen in infragranular layers (V and VI), and decreases in supragranular layers (II and III). The reduction in the visual response was also largest in supragranular layers. We conclude that activation of metabotropic glutamate receptors has both facilitatory and depressive effects in visual cortex, and the effect depends on the layer of the cell recorded.

scholarly journals The Role of Spared Calcarine Cortex and Lateral Occipital Cortex in the Responses of Human Hemianopes to Visual Motion

2004 ◽  
Vol 16 (2) ◽  
pp. 204-218 ◽  
Author(s):  
Antony B. Morland ◽  
Sandra Lê ◽  
Erin Carroll ◽  
Michael B. Hoffmann ◽  
Alidz Pambakian
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Motion ◽  
Neural Mechanism ◽  
Visual Pathways ◽  
The Other ◽  
Visual Response ◽  
Visual Responses ◽  
Behavioral Experiments ◽  
Residual Vision

Some patients, who are rendered perimetrically blind in one hemifield by cortical lesions, nevertheless exhibit residual visual capacities within their field defects. The neural mechanism that mediates the residual visual responses has remained the topic of considerable debate. One explanation posits the subcortical visual pathways that bypass the primary visual cortex and innervate the extrastriate visual areas as the substrate that underlies the residual vision. The other explanation is that small islands of the primary visual cortex remain intact and provide the signals for residual vision. We have performed behavioral and functional magnetic resonance imaging experiments to investigate the validity of the two explanations of residual vision. Our behavioral experiments indicated that of the seven hemianopes tested, two had the ability to discriminate the direction of a drifting grating. This residual visual response was shown with fMRI to be the result of spared islands of calcarine cortical activity in one of the hemianopes, whereas only lateral occipital activity was documented in the other patient. These results indicate that the underlying neural correlates of residual vision can vary between patients. Moreover, our study emphasizes the necessity of ruling out the presence of islands of preserved function and primary visual cortex before assigning residual visual capacities to the properties of visual pathways that bypass the primary visual cortex.

Effects of vasoactive intestinal polypeptide on the response properties of cells in area 17 of the cat visual cortex

1993 ◽  
Vol 69 (5) ◽  
pp. 1465-1474 ◽  
Author(s):  
P. C. Murphy ◽  
K. L. Grieve ◽  
A. M. Sillito
Keyword(s):  
Visual Cortex ◽  
Spontaneous Activity ◽  
Vasoactive Intestinal Polypeptide ◽  
Signal To Noise Ratio ◽  
Response Magnitude ◽  
Visual Response ◽  
Area 17 ◽  
Signal To Noise ◽  
Cortical Cells ◽  
Cholinergic Agonist

1. Vasoactive intestinal polypeptide (VIP) was iontophoretically applied to a population of 90 single cells in the primary visual cortex (area 17) of the cat. Response magnitude, response selectivity, spontaneous activity, and the ratio between the visual response and spontaneous activity (signal-to-noise ratio) of the cells were assessed quantitatively before and during drug application. 2. VIP had little effect in the absence of visual stimulation, with only 29/90 (32%) of the cells showing a change of even 1 sp/s in their spontaneous activity. In contrast it had a clear effect on the visual responses of the majority (73/90, 81%) of the cells tested. 3. VIP produced a substantial change (i.e., > or = 40%) in optimal response magnitude for 57 of the affected cells. Of these 65% were facilitated, usually with no change or an improvement in signal-to-noise ratio and direction selectivity. The remaining cells were inhibited, with more variable effects on their visual response characteristics, and were found predominantly in the superficial laminae. 4. The effects of VIP bore a remarkable resemblance to those reported previously for the muscarinic action of acetylcholine (ACh). VIP and a muscarinic cholinergic agonist, either ACh or acetyl-beta-methacholine (MeCh), were therefore applied in turn to a group of 40 cells. In 23 cases VIP and the muscarinic agonist were also applied simultaneously. 5. The effects of VIP and the cholinergic agonist matched in 92% of the cases where both drugs were effective. That is to say, cells that were facilitated by VIP were facilitated also by ACh or MeCh, and vice versa. In many instances there was a clear similarity in the pattern as well as the direction of the effects produced by the two substances. The result of simultaneous application was generally additive. 6. These data suggest that VIP and ACh activate very similar postsynaptic mechanisms, and share a closely related function at the level of individual cortical cells. Thus VIP may facilitate the responses of both the excitatory and the inhibitory components of the cortical circuit, leading to an overall increase in responsiveness and selectivity. In contrast to the cholinergic input from the basal forebrain, however, the VIP-positive cortical cells are likely to exert a very localized influence, over a circumscribed region of the cortex, in response to the presence of an effective visual stimulus.

Glycine at the NMDA receptor in cat visual cortex: saturation and changes with age

1996 ◽  
Vol 75 (1) ◽  
pp. 311-317 ◽  
Author(s):  
D. Czepita ◽  
N. W. Daw ◽  
S. N. Reid
Keyword(s):  
Visual Cortex ◽  
Nmda Receptor ◽  
Nmda Receptors ◽  
Visual Response ◽  
Glycine Site ◽  
Positive Evidence ◽  
Cat Visual Cortex ◽  
Site Of Action

1. Saturation of the glycine site at the N-methyl-D-aspartate (NMDA) receptor in cat visual cortex was tested by iontophoresing D-serine, and the contribution of this site to the visual response was tested by iontophoresing 7-chlorokynurenic acid (7-Cl-KYNA). Animals were tested at ages 3 wk, 6 wk, 5 mo, and adult. 2. In at least 40% of cells (24/57), D-serine increased the response significantly, showing that the glycine site was not saturated. However, the increase was rarely > 100%. 3. The amount by which D-serine increased the response did not vary significantly with age. 4. In five cases there was positive evidence for saturation of the glycine site. D-Serine did not increase the response significantly; however, when D-serine was applied on top of 7-Cl-KYNA, it did increase the response compared with that seen with 7-Cl-KYNA alone. These cases were all in 3-wk-old animals. In other cases (28/57), D-serine did not increase the response significantly, but we could not be absolutely certain that the D-serine had reached the site of action. 5. The effect of 7-Cl-KYNA was largest in 3-wk animals, in agreement with previous findings that the effect of D-2-amino-5-phosphonovalerate (APV) is largest at this age. 6. These results may provide a small part of the explanation for the finding that the NMDA receptor-mediated component of the visual response decreases between 3 and 6 wk of age, while the number of NMDA receptors is increasing. However, the magnitude of the results make it likely that other factors are more important.

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