Abstract:
:Surround enhancement (sensitization) is a poorly understood form of network adaptation in which the kinetics of the responses of retinal neurons to test stimuli become faster, and absolute sensitivity of the responses increases with increasing level of steady, surrounding light. Surround enhancement has been observed in all classes of retinal neurons in lower vertebrates except cones, in some primate retinal ganglion cells, and in human psychophysical studies. In theory, surround enhancement could be mediated by two broad classes of mechanisms, which are not mutually exclusive: one in which the kinetics of the transduction linking cone voltage to postsynaptic current in second-order neurons is modulated, and another in which the transformation of postsynaptic current to membrane voltage is modulated. We report here that both classes of mechanism play a role in surround enhancement measured in turtle horizontal cells (HCs). We stimulated the retina by modulating sinusoidally the illuminance of a bar placed at various positions in the HC receptive field. The bar was surrounded by either equally luminant or dim, steady light. Interpretation of responses in the context of a model for the cone-HC network led to the conclusion that the speeding up of response kinetics--due to selective increase in response gain at high temporal frequencies--by surround illuminance is almost completely accounted for by the change in the kinetics of the transduction linking cone membrane potential to HC postsynaptic current. However, surround illuminance also had an additional, surprising effect on the transformation between postsynaptic current and voltage: the space constant for signal spread in the HC network for the dim-surround condition was roughly twice as large as that for the bright-surround condition. Thus, increasing surround illuminance had analogous effects in the spatial and temporal domains: it restricted the time course and the spatial spread of signal. Both effects were dependent on the contrast between the mean bar illuminance and that of the surround, rather than on overall light level. When the stimulus with the bright surround was dimmed uniformly by a neutral density filter, the space constant did not increase, and response gain at high temporal frequencies did not decrease. Pharmacological experiments performed with dopamine and various agonists and antagonists indicated that, although exogenous dopamine can influence surround enhancement, endogenous dopamine does not play an important role in surround enhancement. We conclude that contrast in background light modulates the spatiotemporal properties of signal processing in the outer retina, and does so by a non-dopaminergic mechanism.
journal_name
Vis Neuroscijournal_title
Visual neuroscienceauthors
Reifsnider ES,Tranchina Ddoi
10.1017/s0952523800006751subject
Has Abstractpub_date
1995-11-01 00:00:00pages
1105-26issue
6eissn
0952-5238issn
1469-8714pii
S0952523800006751journal_volume
12pub_type
杂志文章abstract::Starburst amacrine cells (SACs), the only acetylcholine (ACh)-releasing amacrine cells (ACs) in adult rabbit retina, contain GABA and are key elements in the retina's directionally selective (DS) mechanism. Unlike many other GABAergic ACs, they use glutamic acid decarboxlyase (GAD)(67), not GAD(65), to synthesize GABA...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523810000052
更新日期:2010-03-01 00:00:00
abstract::The responses of neurons in primary visual cortex (V1) are suppressed by stimuli presented in the region surrounding the receptive field. There is debate as to whether this surround suppression is due to intracortical inhibition, is inherited from lateral geniculate nucleus (LGN), or is due to a combination of these f...
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doi:10.1017/S0952523807070563
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journal_title:Visual neuroscience
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更新日期:2008-05-01 00:00:00
abstract::The visual information that first-order cortical cells receive is contained in the visually evoked spike trains of geniculate relay cells. To address functional issues such as the ON/OFF structure of visual cortical receptive fields with modelling studies, a geniculate cell model is needed where the spatial and tempor...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523898156158
更新日期:1998-11-01 00:00:00
abstract::Five lagged cells were recognized by extracellular recording in the lateral geniculate nucleus of an awake, behaving macaque monkey. Previous reports of lagged cells were all in the anesthetized cat. Both parvocellular and magnocellular lagged cells were observed. Response timing was distributed continuously across th...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523808080784
更新日期:2008-09-01 00:00:00
abstract::Many diverse retinal disorders are characterized by retinal edema; yet, little experimental attention has been given to understanding the fundamental mechanisms underlying and contributing to these fluid-based disorders. Water transport in and out of cells is achieved by specialized membrane channels, with most rapid ...
journal_title:Visual neuroscience
pub_type: 杂志文章,评审
doi:10.1017/S0952523809090038
更新日期:2009-03-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800002558
更新日期:1991-06-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523806233388
更新日期:2006-05-01 00:00:00
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journal_title:Visual neuroscience
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doi:10.1017/S0952523806230062
更新日期:2006-09-01 00:00:00
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更新日期:1996-05-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523804213256
更新日期:2004-05-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523803201036
更新日期:2003-01-01 00:00:00
abstract::The morphological characteristics of the eyes and the retinae of lanternfish larvae of Lampanyctus crocodilus, Benthosema glaciale, and Myctophum punctatum were analyzed in pre-flexion, flexion, and post-flexion stages. Pre-flexion larvae of L. crocodilus, the species with the shallowest depth distribution, had spheri...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523807070484
更新日期:2007-05-01 00:00:00
abstract::GABA is a major inhibitory neurotransmitter in the mammalian retina and it acts at many different sites via a variety of postsynaptic receptors. These include GABAA receptors and bicuculline-resistant GABAC receptors. The release of acetylcholine (ACh) is inhibited by GABA and strongly potentiated by GABA antagonists....
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800011652
更新日期:1997-09-01 00:00:00
abstract::Although galvanic vestibular stimulation (GVS) is known to affect the speed and accuracy of visual judgments, the underlying electrophysiological response has not been explored. In the present study, we therefore investigated the effect of GVS on the N170 event-related potential, a marker commonly associated with earl...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523812000235
更新日期:2012-09-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523808080930
更新日期:2009-01-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523802194090
更新日期:2002-07-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S095252381300059X
更新日期:2014-01-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s095252380118404x
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journal_title:Visual neuroscience
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更新日期:1996-07-01 00:00:00
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journal_title:Visual neuroscience
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doi:10.1017/s0952523800003175
更新日期:1993-01-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800171093
更新日期:2000-01-01 00:00:00
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journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800003230
更新日期:1993-01-01 00:00:00
abstract::The purpose of the present study was to compare standard multifocal visual evoked potential (mfVEP) pattern-reversal responses with those produced by pattern-onset, pattern-offset, and pulsed pattern stimuli. mfVEP recordings were obtained from five normal subjects using VERIS and a 4-electrode array. The standard rev...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523808080954
更新日期:2009-03-01 00:00:00
abstract::Experiments on the lateral geniculate nucleus (LGN) of the cat based on 14C 2-deoxyglucose (2-DG) autoradiography and intraocular injections of 2-amino-4-phosphonobutyric acid (APB) provided evidence for gradients of metabolic activity in the ON and OFF pathways in layer A, but only very weakly, if at all, in layer A1...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523800010130
更新日期:1993-11-01 00:00:00
abstract::For over 30 years there has been a controversy over whether color-defined motion can be perceived by the human visual system. Some results suggest that there is no chromatic motion mechanism at all, whereas others do find evidence for a purely chromatic motion mechanism. Here we examine the chromatic input to global m...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/s0952523803204077
更新日期:2003-07-01 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::To better understand the evolution of spatial and color vision, the number and spatial distributions of cones, rods, and optic nerve axon numbers were assessed in seven New World primates (Cebus apella, Saimiri ustius, Saguinus midas niger, Alouatta caraya, Aotus azarae, Calllithrix jacchus, and Callicebus moloch). Th...
journal_title:Visual neuroscience
pub_type: 杂志文章
doi:10.1017/S0952523808080371
更新日期:2008-05-01 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