Effect of dark rearing on the volume of visual cortex (areas 17 and 18) and number of visual cortical cells in young kittens

1992 ◽  
Vol 32 (3) ◽  
pp. 449-459 ◽  
Author(s):  
József Takács ◽  
P. Saillour ◽  
M. Imbert ◽  
M. Bogner ◽  
J. Hámori
Keyword(s):  
Visual Cortex ◽  
Cortical Cells ◽  
Areas 17 And 18 ◽  
Visual Cortical ◽  
Dark Rearing

Role of visual experience in activating critical period in cat visual cortex

1985 ◽  
Vol 53 (2) ◽  
pp. 572-589 ◽  
Author(s):  
G. D. Mower ◽  
W. G. Christen
Keyword(s):  
Visual Cortex ◽  
Visual Experience ◽  
Ocular Dominance ◽  
Orientation Selectivity ◽  
Monocular Deprivation ◽  
Total Darkness ◽  
Cortical Cells ◽  
Visual Cortical ◽  
Dark Rearing ◽  
Made In

Cats were reared in total darkness from birth until 4-5 mo of age (DR cats, n = 7) or with very brief visual experience (1 or 2 days) during an otherwise similar period of dark rearing [DR(1) cats, n = 3; DR(2) cats, n = 7]. Single-cell recordings were made in area 17 of visual cortex at the end of this rearing period and/or after a subsequent prolonged period of monocular deprivation. Control observations were made in normal cats (n = 3), cats reared with monocular deprivation from birth (n = 4), and cats monocularly deprived after being reared normally until 4 mo of age (n = 2). After rearing cats in total darkness, the majority of visual cortical cells were binocularly driven and the overall distribution of ocular dominance was not different from that of normal cats. Orientation-selective cells were very rare in dark-reared cats. Monocular deprivation imposed after dark rearing resulted in selective development of connections from the open eye. Most cells were responsive only to the open eye and the majority of these were orientation selective. These results were similar to, though less severe than, those found in cats reared with monocular deprivation from birth. Monocular deprivation imposed after 4 mo of normal rearing did not produce selective development of connections from the open eye in terms of either ocular dominance or orientation selectivity. In DR(1) cats visual cortical physiology was degraded in comparison to dark-reared cats after the rearing period. Most cells were binocularly driven but there was a higher frequency of unresponsive cells and a reduced frequency of orientation-selective cells. Subsequent monocular deprivation resulted in a further decrease in the number of binocularly driven cells and an increase in unresponsive cells. However, it did not produce a bias in favor of the open eye in terms of either ocular dominance or orientation selectivity. In DR(2) cats there was a high incidence of unresponsive cells and a marked loss of binocularly driven cells after the rearing period. Subsequent monocular deprivation failed to produce any significant changes.(ABSTRACT TRUNCATED AT 400 WORDS)

Interocular torsional disparity and visual cortical development in the cat

1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ocular Dominance ◽  
Visual Fields ◽  
Receptive Fields ◽  
Right Visual Field ◽  
Orientation Columns ◽  
Areas 17 And 18 ◽  
The Right ◽  
Visual Cortical

1. The present experiments were designed to assess the effects of relatively large optically induced interocular torsional disparities on the developing kitten visual cortex. Kittens were reared with restricted visual experience. Three groups viewed a normal visual environment through goggles fitted with small prisms that introduced torsional disparities between the left and right eyes' visual fields, equal but opposite in the two eyes. Kittens in the +32 degrees goggle rearing condition experienced a 16 degrees counterclockwise rotation of the left visual field and a 16 degrees clockwise rotation of the right visual field; in the -32 degrees goggle condition the rotations were clockwise in the left eye and counterclockwise in the right. In the control (0 degree) goggle condition, the prisms did not rotate the visual fields. Three additional groups viewed high-contrast square-wave gratings through Polaroid filters arranged to provide a constant 32 degrees of interocular orientation disparity. 2. Recordings were made from neurons in visual cortex around the border of areas 17 and 18 in all kittens. Development of cortical ocular dominance columns was severely disrupted in all the experimental (rotated) rearing conditions. Most cells were classified in the extreme ocular dominance categories 1, 2, 6, and 7. Development of the system of orientation columns was also affected: among the relatively few cells with oriented receptive fields in both eyes, the distributions of interocular disparities in preferred stimulus orientation were centered near 0 degree but showed significantly larger variances than in the control condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Postnatal development of functional properties of visual cortical cells in rats with excitotoxic lesions of basal forebrain cholinergic neurons

1997 ◽  
Vol 14 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Rosita Siciliano ◽  
Gigliola Fontanesi ◽  
Fiorella Casamenti ◽  
Nicoletta Berardi ◽  
Paola Bagnoli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Postnatal Development ◽  
Functional Properties ◽  
Basal Forebrain ◽  
Critical Period ◽  
Ocular Dominance ◽  
Cholinergic Neurons ◽  
Field Size ◽  
Cortical Cells ◽  
Visual Cortical

AbstractIn the rat, visual cortical cells develop their functional properties during a period termed as critical period, which is included between eye opening, i.e.˘postnatal day (PD) 15, and PD40. The present investigation was aimed at studying the influence of cortical cholinergic afferents from the basal forebrain (BF) on the development of functional properties of visual cortical neurons. At PD15, rats were unilaterally deprived of the cholinergic input to the visual cortex by stereotaxic injections of quisqualic acid in BF cholinergic nuclei projecting to the visual cortex. Cortical cell functional properties, such as ocular dominance, orientation selectivity, receptive-field size, and cell responsiveness were then assessed by extracellular recordings in the visual cortex ipsilateral to the lesioned BF both during the critical period (PD30) and after its end (PD45). After the recording session, the rats were sacrificed and the extent of both cholinergic lesion in BF and cholinergic depletion in the visual cortex was determined. Our results show that lesion of BF cholinergic nuclei transiently alters the ocular dominance of visual cortical cells while it does not affect the other functional properties tested. In particular, in lesioned animals recorded during the critical period, a higher percentage of visual cortical cells was driven by the contralateral eye with respect to normal animals. After the end of the critical period, the ocular dominance distribution of animals with cholinergic deafferentation was not significantly different from that of controls. Our results suggest the possibility that lesions of BF cholinergic neurons performed during postnatal development only transiently interfere with cortical competitive processes.

Binocular competition affects the pattern and intensity of ocular activation columns in the visual cortex of cats

1989 ◽  
Vol 2 (4) ◽  
pp. 391-407 ◽  
Author(s):  
N. Tumosa ◽  
S. B. Tieman ◽  
D. G. Tieman
Keyword(s):  
Visual Cortex ◽  
Competitive Advantage ◽  
Monocular Deprivation ◽  
Area 17 ◽  
Large Area ◽  
Cortical Cells ◽  
Areas 17 And 18 ◽  
Binocular Competition ◽  
Video Densitometry ◽  
Average Size

AbstractThe effect of binocular competition on the development of ocular activation columns in areas 17 and 18 of cats was studied using the 14C-2-deoxyglucose (14C-2DG) technique to visualize the regions of cortex activated by one eye in cats reared with equal alternating monocular exposure (equal AME), unequal AME, or monocular deprivation (MD). The average size of the ocular activation columns of the eye stimulated during administration of 2DG was positively correlated with the competitive advantage during rearing. In order of increasing percentage of visual cortex activated, the eyes were (1) deprived eye of MD cats, (2) less experienced eye of unequal AME cats, (3) either eye of equal AME cats, (4) more experienced eye of unequal AME cats, and (5) experienced eye of MD cats. In area 17, the shape of the activation columns also was affected by the relative experience of the eye. The columns of the deprived eye of MD cats were widest in layer IV, where they were about the same width as those of the less experienced eye of the unequal AME cats; in other layers they were narrower, sometimes disappearing altogether. In contrast, the activation columns of the less experienced eye of the unequal AME cats were about the same width in all layers. These results suggest that when one eye is placed at a severe disadvantage and receives no patterned input, as in MD, both geniculocortical connections and intracortical connections may be disrupted, but when the disadvantage is less, as in unequal AME, only the geniculocortical connections are disrupted.Binocular competition also affected the intensity of activation within columns in area 17. We used video densitometry to determine ratios of the amount of label in cortical and thalamic structures. Both the ratio of label in area 17 to that in the lateral geniculate nucleus (LGN) and the ratio of label in the binocular segment of area 17 to that in the monocular segment were significantly less for the deprived eye of MD cats than for any other group. These results suggest that even within the smaller activation columns, deprived geniculocortical afferents are relatively ineffective at driving cortical cells. This finding is consistent with earlier reports that the synapses from the deprived pathway are both morphologically abnormal and reduced in number. The cortical labeling for the less experienced eye of the unequal AME cats and the experienced eye of the MD cats were also significantly less than that in equal AME cats. The decreased labeling for the experienced eye activation columns suggests that, in order to cover an abnormally large area, afferents representing the experienced eye must make fewer synaptic contacts within that area and that there are intrinsic limits on the number of synapses that one axon can make.

scholarly journals Dark Rearing Promotes the Recovery of Visual Cortical Responses but Not the Morphology of Geniculocortical Axons in Amblyopic Cat

2021 ◽  
Vol 15 ◽  
Author(s):  
Takahiro Gotou ◽  
Katsuro Kameyama ◽  
Ayane Kobayashi ◽  
Kayoko Okamura ◽  
Takahiko Ando ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Cortical Neurons ◽  
Visual Pathway ◽  
Monocular Deprivation ◽  
Postnatal Life ◽  
Visual Neurons ◽  
Cortical Responses ◽  
Soma Size ◽  
Visual Cortical ◽  
Dark Rearing

Monocular deprivation (MD) of vision during early postnatal life induces amblyopia, and most neurons in the primary visual cortex lose their responses to the closed eye. Anatomically, the somata of neurons in the closed-eye recipient layer of the lateral geniculate nucleus (LGN) shrink and their axons projecting to the visual cortex retract. Although it has been difficult to restore visual acuity after maturation, recent studies in rodents and cats showed that a period of exposure to complete darkness could promote recovery from amblyopia induced by prior MD. However, in cats, which have an organization of central visual pathways similar to humans, the effect of dark rearing only improves monocular vision and does not restore binocular depth perception. To determine whether dark rearing can completely restore the visual pathway, we examined its effect on the three major concomitants of MD in individual visual neurons, eye preference of visual cortical neurons and soma size and axon morphology of LGN neurons. Dark rearing improved the recovery of visual cortical responses to the closed eye compared with the recovery under binocular conditions. However, geniculocortical axons serving the closed eye remained retracted after dark rearing, whereas reopening the closed eye restored the soma size of LGN neurons. These results indicate that dark rearing incompletely restores the visual pathway, and thus exerts a limited restorative effect on visual function.

Modulatory effects of catecholamines on neurons of the rat visual cortex: single-cell iontophoretic studies

1989 ◽  
Vol 67 (6) ◽  
pp. 615-623 ◽  
Author(s):  
Arlette Kolta ◽  
Tomás A. Reader
Keyword(s):  
Visual Cortex ◽  
Adrenergic Receptors ◽  
Signal To Noise Ratio ◽  
Single Cells ◽  
Firing Frequency ◽  
Adrenergic Agonist ◽  
Cortical Cells ◽  
Hyperpolarizing Response ◽  
Main Component ◽  
Visual Cortical

The catecholamines noradrenaline and dopamine have been proposed as neuromodulators of cortical neuron excitability, and such a regulation could be mediated by specific adrenergic and dopaminergic receptors. We characterized electrophysiologically some of the types of responses to the iontophoretic application of adrenergic and dopaminergic agonists and antagonists on single cells in the rat visual cortex (areas occipital 1 monocular or Oc 1 M and occipital 1 binocular or Oc 1 B). For the majority of spontaneously active and visual cortical cells, noradrenaline and dopamine decreased the firing frequency. In the case of visually driven (synaptically activated) neurons, background firing was the main component of the response to be inhibited by the administration of noradrenaline, clonidine, and oxymetazoline, leading to an enhancement of the signal-to-noise ratio. Since these effects could be reduced or blocked by a previous ejection of the specific α2-antagonist idazoxan, the findings support a role for α2-adrenergic receptors in the transmission of sensory inputs to the visual cortex. These effects were not found with the mixed α-adrenergic agonist phenylephrine nor with the β-agonist isoproterenol. Finally, the use of the inhibitory amino acid GABA rules out a simple hyperpolarizing response as the mechanism underlying noradrenaline modulatory effects in the cerebral cortex.Key words: visual cortex, noradrenaline, dopamine, iontophoresis, neuromodulators.

scholarly journals Diversity of feature selectivity in macaque visual cortex arising from limited number of broadly-tuned input channels

2018 ◽  
Author(s):  
Yamni S. Mohan ◽  
Jaikishan Jayakumar ◽  
Errol K.J. Lloyd ◽  
Ekaterina Levichkina ◽  
Trichur R. Vidyasagar
Keyword(s):  
Visual Cortex ◽  
Cortical Neurons ◽  
Full Range ◽  
Cortical Cells ◽  
Thalamic Input ◽  
Feature Selectivity ◽  
The One ◽  
Visual Cortical ◽  
Orientation Domain ◽  
Preferred Stimulus

AbstractSpikes (action potential) responses of most primary visual cortical cells in the macaque are sharply tuned for the orientation of a line or an edge and neurons preferring similar orientations are clustered together in cortical columns. The preferred stimulus orientation of these columns span the full range of orientations, as observed in recordings of spikes, which represent the outputs of cortical neurons. However, when we imaged also the thalamic input to these cells that occur on a larger spatial scale, we found that the orientation domain map of the primary visual cortex did not show the diversity of orientations exhibited by signals representing outputs of the cells. This map was dominated by just the one orientation that is most commonly represented in subcortical responses. This supports cortical feature selectivity and columnar architecture being built upon feed-forward signals transmitted from the thalamus in a very limited number of broadly-tuned input channels.

Cholinergic and noradrenergic afferents influence the functional properties of the postnatal visual cortex in rats

1999 ◽  
Vol 16 (6) ◽  
pp. 1015-1028 ◽  
Author(s):  
ROSITA SICILIANO ◽  
FRANCESCO FORNAI ◽  
IRENE BONACCORSI ◽  
LUCIANO DOMENICI ◽  
PAOLA BAGNOLI
Keyword(s):  
Visual Cortex ◽  
Functional Properties ◽  
Cortical Neurons ◽  
Developmental Plasticity ◽  
Signal To Noise Ratio ◽  
Ocular Dominance ◽  
Field Size ◽  
Cortical Cells ◽  
Visual Cortical ◽  
Na Depletion

Based on previous evidence that acetylcholine (ACh) and noradrenaline (NA) play a permissive role in developmental plasticity in the kitten visual cortex, we reinvestigated this topic in the postnatal visual cortex of rats with normal vision. In rats, the functional properties of visual cortical cells develop gradually between the second and the sixth postnatal week (Fagiolini et al., 1994). Cortical cholinergic depletion, by basal forebrain (BF) lesions at postnatal day (PD) 15 (eye opening), leads to a transient disturbance in the distribution of ocular dominance (Siciliano et al., 1997). In the present study, we investigated the development of visual cortical response properties following cytotoxic lesions of the locus coeruleus (LC) alone or in combination with lesions of cholinergic BF. The main result is that early NA depletion impairs the orientation selectivity of cortical neurons, causes a slight increase of their receptive-field size, and reduces the signal-to-noise ratio of cell responses. Similar effects are obtained following NA depletion in adult animals, although the effects of adult noradrenergic deafferentation are significantly more severe than those obtained after early NA depletion. Additional cholinergic depletion causes an additional transient change in ocular-dominance distribution similarly to that obtained after cholinergic deafferentation alone. Comparisons between depletion of NA on the one hand and depletion of both NA and ACh on the other suggest that the effects of combined deafferentation on the functional properties studied result from simple linear addition of the effects of depleting each afferent system alone.

scholarly journals Diversity of Feature Selectivity in Macaque Visual Cortex Arising from a Limited Number of Broadly Tuned Input Channels

2019 ◽  
Vol 29 (12) ◽  
pp. 5255-5268
Author(s):  
Yamni S Mohan ◽  
Jaikishan Jayakumar ◽  
Errol K J Lloyd ◽  
Ekaterina Levichkina ◽  
Trichur R Vidyasagar
Keyword(s):  
Visual Cortex ◽  
Full Range ◽  
Cortical Cells ◽  
Intrinsic Signals ◽  
Thalamic Input ◽  
Feature Selectivity ◽  
The One ◽  
Visual Cortical ◽  
Orientation Domain ◽  
Preferred Stimulus

AbstractSpike (action potential) responses of most primary visual cortical cells in the macaque are sharply tuned for the orientation of a line or an edge, and neurons preferring similar orientations are clustered together in cortical columns. The preferred stimulus orientation of these columns span the full range of orientations, as observed in recordings of spikes and in classical optical imaging of intrinsic signals. However, when we imaged the putative thalamic input to striate cortical cells that can be seen in imaging of intrinsic signals when they are analyzed on a larger spatial scale, we found that the orientation domain map of the primary visual cortex did not show the same diversity of orientations. This map was dominated by just the one orientation that is most commonly preferred by neurons in the retina and the lateral geniculate nucleus. This supports cortical feature selectivity and columnar architecture being built upon feed-forward signals transmitted from the thalamus in a very limited number of broadly tuned input channels.

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