Abstract:
:Transgenic mice overexpressing bcl-2, due to inhibition of naturally occurring cell death, have much larger brains and optic nerves as compared to wild-type mice. Since developmental cell death is believed to exert a crucial role in establishing the mature neural circuitry and function, we asked the question of whether basic aspects of vision were altered in bcl-2 mice. Local visually evoked potentials (VEPs) in response to patterned stimuli were recorded from the primary visual cortex. The representation of the vertical meridian was displaced by about 15% in the bcl-2 mouse, accounting for brain expansion. However, visual acuity, contrast threshold, and response latency were normal, indicating that compensatory mechanisms can ensure normal basic properties of vision in spite of marked neuronal redundancy.
journal_name
Vis Neuroscijournal_title
Visual neuroscienceauthors
Porciatti V,Pizzorusso T,Maffei Ldoi
10.1017/s0952523899164113subject
Has Abstractpub_date
1999-07-01 00:00:00pages
721-6issue
4eissn
0952-5238issn
1469-8714pii
S0952523899164113journal_volume
16pub_type
杂志文章abstract::Accommodation is more accurate with polychromatic stimuli than with narrowband or monochromatic stimuli. The aim of this paper is to develop a computational model for how the visual system uses the extra information in polychromatic stimuli to increase the accuracy of accommodation responses. The proposed model is dev...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800000705
更新日期:1990-12-01 00:00:00
abstract::Adult Japanese quail have an endogenous circadian clock located in their eyes that has been shown to regulate melatonin biosynthesis. We investigated if a circadian oscillator is present in cultures of dispersed embryonic quail retina. Melatonin release in retinal cell culture is modulated by the light cycle, indicati...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523899165040
更新日期:1999-09-01 00:00:00
abstract::We studied the functional connectivity of cells in the lateral geniculate nucleus (LGN) with the primary visual cortex (V1) in anesthetized marmosets (Callithrix jacchus). The LGN sends signals to V1 along parallel visual pathways called parvocellular (P), magnocellular (M), and koniocellular (K). To better understand...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523814000066
更新日期:2014-05-01 00:00:00
abstract::Neurons in the superficial layers of the midbrain superior colliculus (SC) exhibit distinct tuning properties for visual stimuli, but, unlike neurons in the geniculocortical visual pathway, most respond best to visual stimuli that are smaller than the classical receptive field (RF). The mechanism underlying this size ...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523806230062
更新日期:2006-09-01 00:00:00
abstract::Recently, we introduced a phototransduction model that was able to account for the reproducibility of vertebrate rod single-photon responses (SPRs) (Hamer et al., 2003). The model was able to reproduce SPR statistics by means of stochastic activation and inactivation of rhodopsin (R*), transducin (G alpha ), and phosp...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523805224045
更新日期:2005-07-01 00:00:00
abstract::Immunohistochemical techniques were used to survey the distribution of several conventional transmitters, receptors, and neuropeptides in the pigeon nucleus of the basal optic root (nBOR), a component of the accessory optic system. Amongst the conventional neurotransmitters/modulators, the most intense labeling of fib...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800005964
更新日期:1989-11-01 00:00:00
abstract::The visual response to a flash given in the dark is known to saturate according to the Michaelis-Menten relationship. Nevertheless, the incremental response from increasing levels of mean luminance tends to follow a Weber-Fechner relationship well into the saturation range determined from the Michaelis-Menten results....
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800006593
更新日期:1991-04-01 00:00:00
abstract::Using suction electrodes, photocurrent responses to 100-ms saturating flashes were recorded from isolated retinal rods of the larval-stage tiger salamander (Ambystoma tigrinum). The delay period (Tc) that preceded recovery of the dark current by a criterion amount (3 pA) was analyzed in relation to the flash intensity...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800006441
更新日期:1992-01-01 00:00:00
abstract::We used qualitative tests to assess the sensitivity of 1043 V2 neurons (predominantly multiunits) in anesthetised macaque monkeys to direction, length, orientation, and color of moving bar stimuli. Spectral sensitivity was additionally tested by noting ON or OFF responses to flashed stimuli of varied size and color. T...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523802191164
更新日期:2002-03-01 00:00:00
abstract::The goal of this work was to provide a detailed quantitative description of the receptive-field properties of one of the types of rarely encountered retinal ganglion cells of cat; the cell named the Q-cell by Enroth-Cugell et al. (1983). Quantitative comparisons are made between the discharge statistics and between th...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800007975
更新日期:1995-03-01 00:00:00
abstract::Dark-adapted rods exert a tonic suppressive influence upon cone-mediated sensitivity to rapid flicker, a phenomenon called suppressive rod-cone interaction (SRCI). However, rod dark adaptation has negligible influence upon cone-mediated thresholds measured with more usual psychophysical procedures. The present study s...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s095252380000924x
更新日期:1992-02-01 00:00:00
abstract::Ultrastructural examination of photoreceptor inner segment ellipsoids in larval (4, 8, and 15 days postfertilization; dpf) and adult zebrafish identified morphologically different types of mitochondria. All photoreceptors had mitochondria of different sizes (large and small). At 4 dpf, rods had small, moderately stain...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S095252381300059X
更新日期:2014-01-01 00:00:00
abstract::Studies of the numbers of retinal ganglion cells and lateral geniculate nucleus (LGN) neurons in primates suggest that the numbers of both types of neurons may vary over a two-fold range from one individual to another. This raises the question of whether the numbers of ganglion cells and LGN neurons are related or var...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800007239
更新日期:1996-01-01 00:00:00
abstract::The neural mechanisms driving perception and saccades during search use information about the target but are also based on an inhibitory surround not present in the target luminance profile (e.g., Eckstein et al., 2007). Here, we ask whether these inhibitory surrounds might reflect a strategy that the brain has adapte...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523809090014
更新日期:2009-01-01 00:00:00
abstract::In human subjects, the blind spot is perceptually filled-in by color and brightness from the surrounding visual field. The present behavioral study examined the occurrence of color filling-in at the blind spot in monkeys. First, the location of the blind spot was determined using a monocular saccade task. The blind sp...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800006921
更新日期:1994-11-01 00:00:00
abstract::Monocular deprivation (MD) by lid suture is one of the classic paradigms for the study of developmental plasticity in the cerebral cortex, and we have detailed knowledge of its anatomical and physiological consequences as well as underlying molecular and cellular mechanisms. However, the effects of other forms of mani...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523812000260
更新日期:2012-09-01 00:00:00
abstract::This study has shown that the retinae of Prototherian (egg-laying) mammals possess two neuronal types that are present in non-mammalian retinae, but absent or morphologically different in the retinae of Eutherian (placental) mammals. First, endogenous serotonin-like immunoreactivity has been localized in a population ...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800000079
更新日期:1990-07-01 00:00:00
abstract::Neighboring retinal ganglion cells often spike synchronously, but the possible function and mechanism of this synchrony is unclear. Recently, the strength of the fast correlation between ON-OFF directionally selective cells of the rabbit retina was shown to be stimulus dependent. Here, we extend that study, investigat...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523807070757
更新日期:2007-11-01 00:00:00
abstract::Multifocal VEP (mfVEP) responses were obtained from 13 normal human subjects for nine test conditions, covering three viewing conditions (dichoptic and left and right monocular), and three different temporal stimulation forms (rapid contrast reversal, rapid pattern pulse presentation, and slow pattern pulse presentati...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523805221053
更新日期:2005-01-01 00:00:00
abstract::In birds, neurons of the isthmo-optic nucleus (ION), as well as "ectopic" neurons, send axons to the retina, where they synapse on cells in the inner nuclear layer (INL). Previous work has shown that centrifugal axons can be divided into two anatomically distinct types depending on their model of termination: either "...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800001747
更新日期:1994-03-01 00:00:00
abstract::Much of what is currently known about the visual response of retinal bipolar cells is based on studies of rod-dominant responses to flashes in the dark in the isolated retina. This minireview summarizes quantitative findings on contrast processing in the intact light-adapted retina based on intracellular recording fro...
journal_title:Visual neuroscience
pub_type: 杂志文章,评审
doi:10.1017/S0952523810000313
更新日期:2011-01-01 00:00:00
abstract::The distributions of rod and cone photoreceptors have been determined in the retina of the California ground squirrel, Spermophilus beecheyi. Retinas were fixed by perfusion and the rods and cones were detected with indirect immunofluorescence using opsin antibodies. Local densities were determined at 2-mm intervals a...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523898154081
更新日期:1998-07-01 00:00:00
abstract::Several lines of evidence indicate that retinal photoreceptors produce melatonin. However, there are other potential melatonin sources in the retina, and melatonin synthesis can be regulated by feedback from the inner retina. To analyze cellular mechanisms of melatonin regulation in retinal photoreceptors, we have dev...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800005009
更新日期:1992-05-01 00:00:00
abstract::Synaptically localized calcium channels shape the timecourse of synaptic release, are a prominent site for neuromodulation, and have been implicated in genetic disease. In retina, it is well established that L-type calcium channels play a major role in mediating release of glutamate from the photoreceptors and bipolar...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523804214055
更新日期:2004-07-01 00:00:00
abstract::Receptive field organization of cone-driven bipolar cells was investigated by intracellular recording in the intact light-adapted retina of the tiger salamander (Ambystoma tigrinum). Centered spots and concentric annuli of optimum dimensions were used to selectively stimulate the receptive field center and surround wi...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523811000071
更新日期:2011-05-01 00:00:00
abstract::Tritiated neurotransmitter candidates were unilaterally injected in visual cortical regions with abundant corpus callosum connections. D-aspartate (Asp) or gamma-aminobutyric acid (GABA) was injected along the area 17/18 border in cat, and the area 17/18a and 17/18b borders in rat. Retrograde Asp label was found contr...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800004351
更新日期:1989-01-01 00:00:00
abstract::Reduction of blood flow to the rat retina was achieved by either clamping both carotid arteries briefly (24 min) or combining clamping of the carotid arteries with permanent occlusion of the vertebral arteries. Analysis of retinas 6 days after operations showed that GFAP immunoreactivity is expressed throughout the re...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800010427
更新日期:1991-12-01 00:00:00
abstract::One type of retinal ganglion cells prefers object motion in a particular direction. Neuronal mechanisms for the computation of motion direction are still unknown. We quantitatively mapped excitatory and inhibitory regions of receptive fields for directionally selective retinal ganglion cells in the Japanese quail, and...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800172086
更新日期:2000-03-01 00:00:00
abstract::Amacrine cells are a morphologically and functionally diverse group of inhibitory interneurons. Morphologically, they have been divided into approximately 30 types. Although this diversity is probably important to the fine structure and function of the retinal circuit, the amacrine cells have been more generally divid...
journal_title:Visual neuroscience
pub_type: 杂志文章,评审
doi:10.1017/S0952523812000028
更新日期:2012-01-01 00:00:00
abstract::The human visual system is remarkably tolerant to degradation in image resolution: human performance in scene categorization remains high no matter whether low-resolution images or multimegapixel images are used. This observation raises the question of how many pixels are required to form a meaningful representation o...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523808080930
更新日期:2009-01-01 00:00:00