The duplex character of the corticofugal pathway from the striate cortex to the lateral geniculate complex of the cat

Boyapati, J.; Henry, G. H.

doi:10.1016/0042-6989(87)90069-1

Cited by 10 publications

(7 citation statements)

References 17 publications

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“…Likewise, most cells responded to visual stimulation through either eye, though the strength of the elicited response was usually stronger for one eye. The responses of perigeniculate cells are often bursty and rather erratic (Sanderson 1971;Dubin and Cleland, 1977;Wrobel and Tarnecki, 1984;Boyapati and Henry, 1987). As a consequence of this variable responsiveness, the exact borders of the receptive fields of some of the PGN cells studied here were sometimes difficult to define precisely (especially to flashed stimulus presentation), as has previously been noted by others (Wrobel and Tarnecki, 1984;Boyapati and Henry, 1987;Uhlrich etal., 1991).…”

Section: Length Tuning In Cortex Intact Preparationsmentioning

confidence: 67%

“…The responses of perigeniculate cells are often bursty and rather erratic (Sanderson 1971;Dubin and Cleland, 1977;Wrobel and Tarnecki, 1984;Boyapati and Henry, 1987). As a consequence of this variable responsiveness, the exact borders of the receptive fields of some of the PGN cells studied here were sometimes difficult to define precisely (especially to flashed stimulus presentation), as has previously been noted by others (Wrobel and Tarnecki, 1984;Boyapati and Henry, 1987;Uhlrich etal., 1991). However, using moving stimuli, we were able to generate quantitative length-response curves which exhibited clearly definable response zones for 10 of the 20 cells studied.…”

Section: Length Tuning In Cortex Intact Preparationsmentioning

confidence: 67%

“…The latter have antagonistic centresurround receptive fields and respond briskly and consistently to small, stationary spots of light flashed within the receptive field centre. In contrast, many PGN cells respond poorly to stationary stimuli but respond best, albeit inconsistently, to moving stimuli (Sanderson, 1971 ;Dubin and Cleland, 1977; Wrobel and Tamecki, 1984; Boyapati and Henry, 1987;Uhlrich er al., 1991). Furthermore, they are usually binocular, generally give on-off responses to small spots of light flashed anywhere in their receptive fields (Sanderson, 1971; Dubin and Cleland, 1977;Xue et al, 1988), and often exhibit marked orientation biases (e.g.…”

Section: Introductionmentioning

confidence: 99%

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The Length – Response Properties of Cells in the Feline Perigeniculate Nucleus

Jones¹,

Sillito²

1994

Eur J of Neuroscience

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Perigeniculate cells receive visual input from the dorsal lateral geniculate nucleus (dLGN) and from the visual cortex. In contrast to the extensive literature documenting dLGN and cortical cell responses, comparatively little quantitative data exists for perigeniculate nucleus cells, and very little is known about the role of the corticofugal input to the perigeniculate nucleus. We have previously shown that dLGN relay cells have sharply length-tuned receptive fields and that a significant component of this is dependent on the corticofugal system. In this report, we have explored the length-response properties of perigeniculate nucleus cells in the presence and absence of corticofugal feedback. The response profiles of most perigeniculate nucleus cells contrasted markedly with the sharply length-tuned fields of dLGN cells, but exhibited a notable resemblance to those exhibited by VI cells with short summation lengths, which have recently been shown to constitute a considerable proportion of the layer VI cell population. This might suggest that the responses of perigeniculate nucleus cells to long bars derive from their cortical input. However, our data failed to reveal a discernible change in their profiles after removal of the corticofugal drive. This surprising observation implies that their length-tuning profiles follow from subcortical circuitry. The ways in which this might occur are discussed.

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Section: Length Tuning In Cortex Intact Preparationsmentioning

confidence: 67%

Section: Length Tuning In Cortex Intact Preparationsmentioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

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The Length – Response Properties of Cells in the Feline Perigeniculate Nucleus

Jones¹,

Sillito²

1994

Eur J of Neuroscience

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“…Individual axons, both coarse and fine, seem to innervate both PGN and LGN (Robson 1983;Boyapati & Henry 1984;Murphy & Sillito 1996;Murphy et al 2000). Similarly, estimates of the conduction velocity from latency measurements provide support for two groups of corticofugal afferents (Tsumoto et al 1978;Tsumoto & Suda 1980;Boyapati & Henry 1987;Grieve & Sillito 1995a) projecting to the LGN and PGN. The fastest pathway allows for a very rapid influence of the corticofugal system on the developing response and would enable the loop from LGN-cell response to cortex and back within a time window of ca.…”

Section: Functional Connectivitymentioning

confidence: 88%

Corticothalamic interactions in the transfer of visual information

Sillito

Jones

2002

Phil. Trans. R. Soc. Lond. B

168

158

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Thalamic function does not stand apart, as a discrete processing step, from the cortical circuitry. The thalamus receives extensive feedback from the cortex and this influences the firing pattern, synchronization and sensory response mode of relay cells. A crucial question concerns the extent to which the feedback simply controls the state and transmission mode of relay cells and the extent to which the feedback participates in the specific processing of sensory information. Using examples from experiments examining the influence of feedback from the visual cortex to the lateral geniculate nucleus (LGN), we argue that thalamic mechanisms are selectively focused by visually driven feedback to optimize the thalamic contribution to segmentation and global integration. This involves effects on both the temporal and spatial parameters characterizing the responses of LGN cells and includes, for example, motion-driven feedback effects from MT (middle temporal visual area) relayed via layer 6 of V1 (primary visual cortex).

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“…Equally, the subcortical synaptic organization influencing dLGN relay cells encompasses a diversity of connections that could well underpin the effects observed here. In particular, we would highlight the specific branching patterns described for the axons of perigeniculate inhibitory interneurones as they project into the A-laminae of the dLGN (Uhlrich, Cucchiaro, Humphrey & Sherman, 1991) and reports of directional responses in perigeniculate nucleus cells (Boyapati & Henry, 1987). Cells in the nucleus of the optic tract also exhibit directional biases (Hoffmann & Stone, 1985), and a projection from this nucleus to the A-laminae of the dLGN has been demonstrated (Graybiel & Berson, 1980;Kubota, Morimoto, Kanaseki & Inomata, 1987).…”

Section: Cells With Directional Biasmentioning

confidence: 99%

Directional asymmetries in the length‐response profiles of cells in the feline dorsal lateral geniculate nucleus.

Jones¹,

Sillito²

1994

The Journal of Physiology

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1. The visual cortex provides a major synaptic input to the dorsal lateral geniculate nucleus (dLGN). Cortical layer VI cells giving rise to this projection are strongly influenced by stimulus orientation, length and direction of motion. In the dLGN, a significant component of the strong length tuning exhibited by most cells follows from the corticofugal influence. We have now checked whether there are directional biases in geniculate cell responses, and whether such biases are influenced by stimulus length. 2. The responses of A‐laminae dLGN cells were assessed by single‐unit extracellular recording. Length preference was examined by plotting multihistogram length‐tuning curves to moving bars of light of various length. 3. Over half of the cells tested (100/183) exhibited directional bias and in many cases, this bias was highly dependent on bar length, resulting in radically different length response profiles for the two directions of motion. These asymmetries are similar to those documented for cortical hypercomplex cells, but do not equate to any known facet of the centre‐surround organization of dLGN cell receptive fields. 4. We suspected the directional biases followed from the influence of the corticofugal projection. To test this, we recorded from preparations where areas 17 and 18 of the visual cortex had been removed. Surprisingly, a similar proportion of cells exhibited directional biases after removal of the corticofugal input, suggesting that the biases are generated subcortically. 5. The widespread presence of systematic biases in the response profiles of dLGN cells further underlines the possibility that geniculate mechanisms may make a far greater contribution to visual processing than hitherto suspected.

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The duplex character of the corticofugal pathway from the striate cortex to the lateral geniculate complex of the cat

Cited by 10 publications

References 17 publications

The Length – Response Properties of Cells in the Feline Perigeniculate Nucleus

The Length – Response Properties of Cells in the Feline Perigeniculate Nucleus

Corticothalamic interactions in the transfer of visual information

Directional asymmetries in the length‐response profiles of cells in the feline dorsal lateral geniculate nucleus.

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