Geniculocortical relay of blue-off signals in the primate visual system

Szmajda, Brett A.; Buzás, Péter; FitzGibbon, Thomas; Martin, Paul R.

doi:10.1073/pnas.0606970103

Cited by 68 publications

(93 citation statements)

References 40 publications

(62 reference statements)

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“…Specifically, in the LGN, S-cone OFF cells are slower and have lower amplitude (impulses per second) than S-cone ON cells (7). A unique result of this study is that older observers differed from younger observers in the temporal dynamics of their S-cone OFF responses.…”

Section: Discussionmentioning

confidence: 63%

“…Separate detection of short-wave-sensitive (S)-cone increments and decrements by different classes of cell is further implied by responses to temporally varying sinusoidal stimuli. Responses of S-cone ON and S-cone OFF cells in the lateral geniculate nucleus (LGN) of the marmoset are ∼180°o ut of phase (7). In the psychophysical domain (8), selective adaptation of putative ON and OFF pathways can be shown following adaptation to sawtooth temporal modulation.…”

mentioning

confidence: 99%

“…The S cones synapse with a specialized S-cone ON bipolar cell (10) that provides the S + signal to a small bistratified ganglion cell that is opposed by middle-wave-sensitive (M) and long-wave-sensitive (L) cone signals (11). The search for a parallel S-cone OFF bipolar cell has been controversial (12-14), notwithstanding unequivocal evidence that a small population of ganglion and LGN cells codes an S-cone OFF response (7,15). Recently, an S-cone OFF signal has been shown to provide input to a melanopsin-containing retinal ganglion cell (16).…”

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confidence: 99%

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Aging of human short-wave cone pathways

Shinomori

Werner

2012

Proc. Natl. Acad. Sci. U.S.A.

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The retinal image is sampled concurrently, and largely independently, by three physiologically and anatomically distinct pathways, each with separate ON and OFF subdivisions. The retinal circuitry giving rise to an ON pathway receiving input from the short-wave-sensitive (S) cones is well understood, but the S-cone OFF circuitry is more controversial. Here, we characterize the temporal properties of putative S-cone ON and OFF pathways in younger and older observers by measuring thresholds for stimuli that produce increases or decreases in S-cone stimulation, while the middle-and long-wave-sensitive cones are unmodulated. We characterize the data in terms of an impulse response function, the theoretical response to a flash of infinitely short duration, from which the response to any temporally varying stimulus may be predicted. Results show that the S-cone response to increments is faster than to decrements, but this difference is significantly greater for older individuals. The impulse response function amplitudes for increment and decrement responses are highly correlated across individuals, whereas the timing is not. This strongly suggests that the amplitude is controlled by neural circuitry that is common to S-cone ON and OFF responses (photoreceptors), whereas the timing is controlled by separate postreceptoral pathways. The slower response of the putative OFF pathway is ascribed to different retinal circuitry, possibly attributable to a sign-inverting amacrine cell not present in the ON pathway. It is significant that this pathway is affected selectively in the elderly by becoming slower, whereas the temporal properties of the S-cone ON response are stable across the life span of an individual. O ne of the most basic properties of primate vision is that each point in the retinal image is sampled by at least three physiologically and anatomically distinct pathways (1, 2). These include a fast, high-contrast sensitivity, low-spatial resolution magnocellular pathway; and a slower, high-spatial resolution, chromatic parvocellular pathway. A third pathway, the koniocellular pathway, is color-opponent and slow, and it has poor spatial resolution. Overlaid onto the organization of these pathways are subdivisions into parallel ON and OFF systems (3). This originates at the first retinal synapse between the cone photoreceptor and the bipolar cell to give rise to the magnocellular or parvocellular pathways, resulting in further specialization and response selectivity for spatiotemporal luminance and/or chromatic increments (ON pathway) or decrements (OFF pathway). The assumption that detection of increments and decrements is mediated by separate ON and OFF pathways is supported by the work of Schiller et al. (4) in alert, behaving monkeys. During retinal infusion of the glutamate neurotransmitter analog 2-amino-4-phosphonobutyrate, which blocks synaptic transmission from cones to ON-bipolar cells but not OFFbipolar cells, there is a profound loss in the ability to detect increments but not decrements. A number of oth...

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Section: Discussionmentioning

confidence: 63%

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confidence: 99%

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confidence: 99%

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Aging of human short-wave cone pathways

Shinomori

Werner

2012

Proc. Natl. Acad. Sci. U.S.A.

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“…1 B and F). The K layers contained receptive fields with heterogeneous properties (25) including S cone-driven ("blue-on" and "blue-off") fields (11,12,26) (Fig. 1 C, E, and H).…”

Section: Methodsmentioning

confidence: 99%

“…1 A-D) (23, 25, 26). Recorded neurons were tested for spatial frequency selectivity, achromatic contrast selectivity, temporal frequency selectivity, and responsivity to specific modulation of short wavelength-sensitive (S or "blue") cone photoreceptors (11,26). The P layers contained receptive fields that were small, gave sustained responses to contrast steps, and showed low contrast sensitivity (Fig.…”

Section: Methodsmentioning

confidence: 99%

Slow intrinsic rhythm in the koniocellular visual pathway

Cheong

Tailby

Martin

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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Slow rhythmic changes in nerve-cell activity are characteristic of unconscious brain states and also may contribute to waking brain function by coordinating activity between cortical and subcortical structures. Here we show that slow rhythms are exhibited by the koniocellular (K) pathway, one of three visual pathways beginning in the eye and projecting through the lateral geniculate visual relay nucleus to the cerebral cortex. We recorded activity in pairs and ensembles of neurons in the lateral geniculate nucleus of anesthetized marmoset monkeys. We found slow rhythms are common in K cells but are rare in parvocellular and magnocellular cell pairs. The time course of slow K rhythms corresponds to subbeta (<10 Hz) EEG frequencies, and high spike rates in K cells are associated with low power in the theta and delta EEG bands. By contrast, spontaneous activity in the parvocellular and magnocellular pathways is neither synchronized nor strongly linked to EEG state. These observations suggest that parallel visual pathways not only carry different kinds of visual signals but also contribute differentially to brain circuits at the first synapse in the thalamus. Differential contribution of sensory streams to rhythmic brain circuits also raises the possibility that sensory stimuli can be tailored to modify brain rhythms.parallel pathways | visual system | sleep-wake cycles | anesthesia | epilepsy T he thalamus is central to brain networks that generate slow rhythmic neural activity in sleep-wake cycles, anesthesia, and epilepsy (1-5). However, the thalamus also provides parallel pathways to cerebral cortex for conscious sensation. These two aspects of thalamic function are not independent, as shown, for example, when repetitive visual stimuli induce epileptic seizures (6). Anatomical studies of the dorsal lateral geniculate nucleus (LGN) show preferential inputs to the LGN koniocellular (K) layers from midbrain centers regulating eye movements and vigilance state (1, 2, 7-9), suggesting that activity in the K system is concerned with brain state as well as with faithful transmission of retinal signals. We found evidence supporting this idea from an unexpected observation on K cells. Results During extracellular recordings fromLGN in anesthetized marmoset monkeys (Fig.1 A-D), we found that in the absence of patterned visual stimuli the spike rate of K cells showed slow fluctuations over the course of several seconds to minutes. An example of these slow intrinsic rhythms in three simultaneously recorded K cells is shown in Fig. 1E. By contrast the spike rate of parvocellular (P) cells (Fig. 1F) and magnocellular (M) cells (Fig. 1G) was stable in the absence of patterned visual stimulus. Retinal ganglion cell inputs to K, P, and M layers show low variation in steady discharges at frequencies below 3 Hz (10); this fact implies that the fluctuations do not arise in the retina. Frequency analysis of maintained spike rates showed that below 1 Hz, K-cell spike rates (n = 56) on average were 33% more variable than P-cell spike ...

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Colour Vision

Gouras¹

2007

Encyclopedia of Life Sciences

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Our daylight photoreceptors, cones, mediate colour vision but by themselves cannot distinguish wavelength from the energy of the light they absorb. By comparing the responses of two cone types, one absorbing best from one end and the other best from the other end of the visible spectrum, energy and wavelength contrasts can be determined independently, and thereby colour vision. In man and many primates, three cone mechanisms are compared; the long wavelength sensitive (L) cones are compared with the middle wavelength sensitive (M) cones to create ‘red/green’ colour vision and the short wavelength sensitive (S) cones are compared with both M and L cones for ‘yellow/blue’ form of colour vision. The latter is the only form of colour vision in most mammals and in 2% of human males. This process involves hierarchical circuits from retina to visual cortex including antagonistic interactions between these cone pairs in the same areas of visual space, ‘single opponency’ in the retina and lateral geniculate nucleus, to comparisons between adjacent areas of visual space, ‘dual opponency’ in visual cortex. By this means energy is dissociated from wavelength contrast to create colour vision where both variables are processed separately and used to sense hue, saturation and brightness, the qualities of colour vision, creating about a million varieties of colour.

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Geniculocortical relay of blue-off signals in the primate visual system

Cited by 68 publications

References 40 publications

Aging of human short-wave cone pathways

Aging of human short-wave cone pathways

Slow intrinsic rhythm in the koniocellular visual pathway

Colour Vision

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