Distribution of enzyme cytochrome oxidase (CO) activity was studied in a continuous series of parasagittal sections of cortical area 17 and frontal sections of dorsal lateral geniculate nucleus (LGNd) in kittens of different age and adult cats.
One comprised of cortical area 17, ventromedial region of LPl-c, and medial MSS, the second involved area 18 and the dorsolateral LPl-c.
Results show that 2D C0 complexity could be employed to reveal the dynamic process of generating an orientation map in the visual cortex, and describe the variance of the neural responses in cortical area 17 under high and normal intraocular pressure.
Following injections of biotinylated dextran amine into cortical area 17, corticotectal axons were labeled by anterograde transport.
The spatial distribution of neuronal connections in cortical area 17 in cats with bilateral convergent strabismus, surgically induced on postnatal days 10-14, was investigated.
Western blotting with an alphaCaMKII threonine-286 phosphorylation-state specific antiserum consistently showed a small, albeit not significant, increase of alphaCaMKII autophosphorylation in the central versus the peripheral region of cortical area 17, and this both in normal subjects as well as in retinal lesion animals with a 3-day post-lesion survival time.
Following injections of biotinylated dextran amine (BDA) into cortical area 17, two types of corticothalamic terminals were labeled by anterograde transport.
In this report, we describe the successful application of this functional proteomics approach to compare protein expression levels in visual cortical area 17 of adult cats and 30-day-old kittens, in order to identify proteins expressed in an age-related fashion.
PURPOSE: To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system.
SUBJECTS: We examined primary visual cortical area 17 in the right and left hemispheres in 6 age- and sex-matched autopsy specimens from 3 WMS-affected brains (1 male and 2 females; mean [ SD] age, 44 [ 14] years) and 3 control brains (1 male and 2 females; mean age, 43 [ 11] years).
We demonstrate the performance of our method in optical intrinsic signal imaging of cat cortical area 17.
Visual cortical area 17 and the transitional area between area 17 and 18a, or between area 17 and 18b projected their axons to the ipsilateral NOT.
The use of quantitative retrograde tract-tracing techniques revealed that the contribution of the lateral posterior thalamic nucleus (LP) is significantly increased following enucleation, while that of the dorsolateral geniculate and the lateral dorsal nuclei is decreased in the thalamocortical afferentation of a region in visual cortical area 17.
We then compared parabrachial and corticogeniculate terminals, identifying the former by BNOS/ChAT labeling and the latter by orthograde transport of biocytin injected into cortical area 17, 18, or 19.
Here we show by optical imaging of intrinsic signals in ferret cortical area 17 that there is a mosaic-like map of direction preference.
The distribution of the enzyme nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase, which is identical to nitric oxide synthase (NOS), was examined in cortical area 17 and the 17/18a border region in the brain of the golden hamster.
In cortical area 17 of the cat, simple receptive fields are arranged in elongated subregions that respond best to bright (on) or dark (off) oriented contours, whereas the receptive fields of their thalamic inputs have a concentric on and off organization.
In cortical area 17, the reduction of Bmax was counterbalanced by an increase in the affinity (Kd) of the radioligand for the binding sites.
The electron microscopic autoradiographic tracing method has been used to examine the morphology and postsynaptic relationships of five projections (retina, cortical area 17, superior colliculus (tectal), parabigeminal nucleus, and pretectum) to the dorsal lateral geniculate nucleus of the greater bush baby Galago crassicaudatus.
The functional organization of long-horizontal inhibitory connections was studied in cat visual cortical area 17, using a combination of electrophysiological recording and anatomical tracing in the same tissue.
Long-Evans hooded rats received unilateral pressure injections of the retrograde tracer wheat germ agglutinin-horseradish peroxidase in either the dorsal lateral geniculate, ventral lateral geniculate, or lateral posterior nucleus of thalamus; superior colliculus, cortical area 17, cortical area 18a/b; cerebellar vermis (lobules VI and VII); or paraflocculus.
Further, they reach the occipital pole early enough to influence the specification and histogenesis of cortical area 17, perhaps by exerting an influence on the deep-to-superficial "wave" of neuronal differentiation in sequentially developing subplate and cortical layers VI, V and IV..
In visual cortical area 17, the number of Fos immunoreactive cells increased rapidly from virtually zero in control kittens that received no visual exposure, to reach high levels in animals that received between 1 and 2 hours of visual experience.
Patterns of acetylcholinesterase (AChE) histochemical staining in cortical area 17 differ in infant and mature rats.
The 2-deoxyglucose autoradiographic technique was used to assess the metabolic activity of cortical area 17, the dorsal and ventral lateral geniculate nuclei, the lateral posterior nucleus, and the superior colliculus, during 5-Hz flashing-pattern (montage of black and white square-wave gratings) and flashing-diffuse (eye covered with white mask) stimulation at three intensities over a 6 log range.
In adult cats, after section of extraocular muscle proprioceptive (EOMP) afferents during the 'critical period', most cortical area 17 cells loose their ability to discriminate changes in binocular spatial disparity.
In cortical area 17 of normally reared cats, Cat 304-positive neurons are densely distributed in 2 bands, in layers IV and V/VI. The laminar differences in the effect of dark rearing on Cat-301 and Cat-304 expression in the visual cortex provides support for the suggestion that layer IV of cortical area 17 may be less susceptible to prolongation of plasticity by dark rearing than layers II/III and V/VI.
The functional organization of visual cortical area 17/18 of the ferret was studied using a double-label 2-deoxyglucose (2-DG) method.
In normal animals, patterns of CO activity were found to reflect underlying patterns of CO protein distribution; for example, puffs of high CO activity in cortical area 17 contained high levels of CO protein.
Intraocular injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) result in anterograde transneuronal labeling of geniculocortical axon terminals in cortical area 17.
Histochemical studies demonstrate that cortical area 17 (primary visual cortex) of the adult rat displays a characteristic laminar pattern of acetylcholinesterase (AChE) activity.
A fluorescent dye (usually fast blue or rhodamine tagged latex microspheres) was injected into cortical area 17 (or area 17 and the lateral part of area 18b) of adult and juvenile (15 - 22 day old) Sprague-Dawley albino rats.
Previous studies have demonstrated that transient patterns of acetylcholinesterase (AChE) activity are characteristic of geniculo-recipient regions of rat cortical area 17 during the second and third postnatal weeks of life. These data suggest that loss of transient AChE activity in cortical area 17 consequent to neonatal enucleation is secondary to enucleation-induced alterations in the dLGN; these alterations include loss of neurons, shrinkage of neurons, and an apparent decrease in the ability of neurons to synthesize AChE.
These experiments show that uniocular injections result in a markedly decreased level of AChE activity in layer IV of the medial part of cortical area 17 contralateral to the injected eye. Binocular injections of TTX result in a reduction of AChE activity in layer IV throughout cortical area 17, similar to the effects of binocular enucleation on PND 3.
In this study, we injected the anterograde tracer 3H-proline into visual cortical area 17 of kittens, aged 4-70 d, and adult cats to visualize the distribution of terminals of the association projections to areas 18, 19, 21a, and the lateral suprasylvian visual cortex.
Transient acetylcholinesterase (AChE) activity is characteristic of cortical area 17 of the developing laboratory rat during the second and third postnatal weeks of life. The present report describes results of 3 sets of experiments aimed at determining the source of transient AChE in cortical area 17. First, placement of lesions in portions of the basal forebrain or in the cingulate bundle results in a decrease in the general pattern of AChE throughout occipital cortex and especially in layer I, but the transient bands of AChE in layers III-IV of cortical area 17 are not eliminated. Second, kainic acid or cobalt chloride injections in cortical area 17 result in the loss of many AChE-positive neuronal somata but do not eliminate the transient pattern of AChE in thalamo-recipient layers of cortical area 17. Third, lesions that include the lateral geniculate nucleus of the thalamus or geniculocortical projections result in a marked loss of the pattern of AChE in thalamo-recipient layers of cortical area 17, without significant loss in other layers of area 17 or in other regions of occipital cortex. These data support the hypothesis that the transient AChE found in thalamo-recipient layers of cortical area 17 is contained within geniculocortical axon terminals..
Callosal cells were labeled by horseradish peroxidase applied to the severed ends of callosal fibers, and [ 3H]norepinephrine (NE) was injected into the crown of the lateral gyrus corresponding to the visual cortical area 17/18 border to label synapses.
Geniculo-recipient layers of visual cortical area 17 in the laboratory rat display a transient pattern of acetylcholinesterase (AChE) activity during the second and third postnatal weeks of life. The appearance of the AChE histochemical reaction product and its distribution in thalamic recipient layers of cortical area 17 suggest that this transient AChE serves as a marker for the region of geniculocortical axon terminals. Neonatal binocular enucleation resulted in an almost complete loss of AChE histochemical staining in thalamic recipient layers throughout cortical area 17, without loss of AChE in other cortical regions.
Using immunohistochemical methods, we have now detected a calcium-binding protein, calbindin-D-28K, which may confer on certain compartments of cortical area 17 the ability to modulate Ca2+ metabolism.
Response properties of cells in the infragranular layers of cortical area 17 of the cat were examined in the absence of input from supragranular layers.
For double labeling studies, unilateral injections of fast blue and nuclear yellow were made in paired motor (sensorimotor cortex and crus II of the lateral cerebellum) or visual (cortical area 17 and paraflocculus) areas of the CNS.
The ability of cats to discriminate between two geometrical outline patterns in the presence of superimposed Gaussian visual noise was tested before and after bilateral removal of cortical area 17 and parts of area 18.
Neonatal monocular enucleation results in a marked decrement in the spatial extent of the AChE activity in layer IV of cortical area 17.
The result of unilateral ablation of visual cortical area 17 in adult cats was consistent with glutamate-aspartate being the neurotransmitter in efferents to the lateral geniculate body, the pulvinar and the visual part of superior colliculus but not in efferents to area 18 and the non-visual strata of superior colliculus.
The highest rCBF (60 +/- 8 mL/100 g/min) was noted in the mesial occipital region corresponding to cortical area 17.
After deposition of horseradish peroxidase (HRP) crystals on the surface of cortical area 17 in 7 adult Wistar albino rats only relay cells were found to be labelled retrogradually in the caudal two thirds of the dorsal lateral geniculate nucleus (dLGN).
The responses of 254 neurons after electrical stimulation of the central-paracentral part of cortical area 17 and of 84 neurons after stimulation of both area 17 and the superior colliculus (SC) were investigated.
Fine slices made through the gray matter perpendicular to the surface of cortical area 17-18 in the cat produced no change in behavioral measures of grating acuity, a modest reduction in vernier acuity and a proportionately larger effect on contour orientation acuity.
Age-related changes in synaptic density in human visual cortical area 17 (striate cortex) were determined, based on counts in material prepared for electron microscopy with the phosphotungstic acid method.
Neurons of the fourth group (eight of 412) had a receptive field of similar structure to that of the simple receptive fields of neurons in cortical area 17.
Microinjection of picoliter quantities of isotonic sodium penicillin through one barrel of a double micropipet into cortical area 17 of cats induced discrete and temporary foci of epileptogenic alteration in evoked potentials.
The lateral geniculate nucleus projects only to cortical area 17, while a lateral sector of the lateral posterior nucleus sends afferents both to area 17 and 18.
We have obtained such information for 32 adjacent neurons in layer IVab of cat cortical area 17 by reconstructing them from electron micrographs of 150 serial sections.
Animals with a total loss of cortical area 17, and with a loss, in some cases, of up to 90% of areas 18 (with and without infringement into area 19), showed about a 30% reduction in grating acuity, a three-fold increase in parallelness and angularity thresholds, and a total loss of contour alignment ability.
This organization has been compared to that of the primate cortical area 17 as described in previous studies and it is discussed in relationship to the distribution of afferents from the dorsal lateral geniculate nucleus (dLGN).
The angle between the visual axes of cats of various ages was determined during paralysis by plotting the receptive fields of neurons in cortical area 17, and extrapolation to the angle of alignment of the freely moving animal was accomplished by comparing pupillary photographs taken before and after immobilization.
Recordings obtained from cells in cortical area 17 indicated that the effects of monocular deprivation are reversible in cats as old as 8 weeks if the animals have been allowed normal visual experience before eye closure.1.
The morphological maturation of several varieties of neurons of cortical area 17 have been followed in Golgi Rapid preparations from Macaque monkeys ranging in age from fetal day 127 to maturity.
Neuronal responses in cortical area 17 evoked by direct stimulation of areas 18 and 19 were investigated in acute experiments on unanesthetized cats.
Averaged visual evoked responses (VER) in cortical area 17 were recorded one hour after the administration of 7-l-phe ACTH4-10 or 7-d-phe ACTH4-10 to artificially ventilated rats, paralysed with gallamine.
The results appear to indicate the intactness of the visual pathways up to and including cortical area 17 in hysterical amblyopia..
After defining the receptive fields of single units in cortical area 17 of anesthetized cats, recurrent on-off stimulation with bars of light of optimal configuration win from a second micropipette; Progressively, three distinct alterations of neuronal activity developed.
Lesions were made in cortical area 17 (Visual I) of eight cats which were then allowed to recover.
[ View All ]