Visual response properties of pretectal units in the nucleus of the optic tract of the opossum

Volchan, Eliane; Rocha‐Miranda, Carlos Eduardo; Diniz, Cristovam Wanderley Picanço; Zinsmeisser, B.; Bernardes, R. F.; Franca, João G.

doi:10.1007/bf00228910

Cited by 47 publications

(27 citation statements)

References 25 publications

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“…Stimulation and lesion studies have confirmed that the NOT has an essential role in driving horizontal optokinetic nystagnus (OKN) in eutherian mammals (e.g., Collewijn 1975b;Schiff et al 1988), while evidence from eye rotation and electrophysiological experiments point toward a similar role in the wallaby (Hoffmann et al 1995). Recordings have been made from the NOT in marsupials (opossum: Volchan et al 1989; wallaby: Hoffmann et al 1995;) and in several eutherian species (e.g., cat: Hoffmann and Schoppmann 1981; ferret: Klauer et al 1990; monkey: Hoffmann et al 1988;Ilg and Hoffmann 1996;Mustari and Fuchs 1990; rabbit: Collewijn 1975a). The NOT has a highly conserved physiology despite significant differences in input structure between species.…”

Section: Introductionmentioning

confidence: 98%

Contrast and Temporal Frequency-Related Adaptation in the Pretectal Nucleus of the Optic Tract

Ibbotson¹

2005

Journal of Neurophysiology

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Ibbotson, M. R. Contrast and temporal frequency related adaptation in the pretectal nucleus of the optic tract. J Neurophysiol 94: 136 -146, 2005. First published February 23, 2005 doi:10.1152/jn.00980.2004. In mammals, many cells in the retino-geniculate-cortical pathway adapt during stimulation with high contrast gratings. In the visual cortex, adaptation to high contrast images reduces sensitivity at low contrasts while only moderately affecting sensitivity at high contrasts, thus generating rightward shifts in the contrast response functions (contrast gain control). Similarly, motion adaptation at particular temporal frequencies (TFs) alters the temporal tuning properties of cortical cells. For the first time in any species, this paper investigates the influence of motion adaptation on both the contrast and TF responses of neurons in the retino-pretectal pathway by recording from direction-selective neurons in the nucleus of the optic tract (NOT) of the marsupial wallaby, Macropus eugenii. This species is of interest because its NOT receives almost all input directly from the retina, with virtually none from the visual cortex (unlike cats and primates). All NOT cells show changes in their contrast response functions after adaptation, many revealing contrast gain control. Contrast adaptation is direction-dependent, preferred directions producing the largest changes. The lack of cortical input suggests that contrast adaptation is generated independently from the cortex in the NOT or retina. Motion adaptation also produces direction-selective effects on the TF tuning of NOT neurons by shifting the location of the optimum TF. Cells that show strong adaptation to contrast also tend to show large changes in TF tuning, suggesting similar intracellular mechanisms. The data are discussed in terms of the generality of contrast adaptation across mammalian species and across unconnected brain regions within the same species. I N T R O D U C T I O NThis paper shows that exposure to moving grating patterns alters the contrast and temporal frequency response functions of highly direction-selective neurons in the pretectal nucleus of the optic tract (NOT) of the marsupial wallaby, Macropus eugenii. These effects resemble those seen in the visual cortex of other species (e.g., cats, Ohzawa et al. 1985). The wallaby pretectum is a retino-recipient region of which the NOT forms a large component . The wallaby pretectum also contains other nuclei such as the olivary pretectal nucleus, as is the case in eutherian mammals (e.g., Hutchins and Weber 1985; for review, Ibbotson and Dreher 2005). The wallaby NOT contains direction-selective neurons that are optimally responsive to wide-field visual motion, as naturally generated by self-movement. Stimulation and lesion studies have confirmed that the NOT has an essential role in driving horizontal optokinetic nystagnus (OKN) in eutherian mammals (e.g., Collewijn 1975b;Schiff et al. 1988), while evidence from eye rotation and electrophysiological experiments point toward a similar rol...

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Section: Introductionmentioning

confidence: 98%

Contrast and Temporal Frequency-Related Adaptation in the Pretectal Nucleus of the Optic Tract

Ibbotson¹

2005

Journal of Neurophysiology

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“…Unresolved, however, is whether or not these nuclei are differentially involved in smooth pursuit, ocular following or OKR (Keller & Crandall, 1983;Suzuki & Keller, 1984;Kato et al, 1986;Hoffmann et al, 1988Hoffmann et al, , 1995May et al, 1988;Mustari et al, 1988;Simpson et al, 1988;Thier et al, 1988Thier et al, , 1991Volchan et al, 1989;Mustari & Fuchs, 1990;Schiff et al, 1990;Suzuki et al, 1990;Wallman, 1993;Inoue et al, 2000;Yakushin et al, 2000;Hoffmann & Fischer, 2001).…”

Section: Introductionmentioning

confidence: 99%

Cognitive neuroscience

1995

Current Opinion in Neurobiology

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Neurons in cortical medial temporal area (MT) and medial superior temporal area (MST) projecting to the dorsolateral pontine nucleus (DLPN) and ⁄ or to the nucleus of the optic tract and dorsal terminal nucleus (NOT-DTN) were identified by antidromic electrical stimulation in five macaque monkeys. Neurons projecting to either target were located in close proximity to each other, and in all subregions of MT and MST sampled. Only a small percentage of the antidromically identified projection neurons (4.4%) sent branches to both the NOT-DTN and the DLPN. Antidromic latencies of neurons projecting to the NOT-DTN (0.9-6 ms, median 2.1 ms) and to the DLPN (0.8-5 ms, median 2.0 ms) did not differ significantly. Visual response properties of the neurons antidromically activated from either site did not differ significantly from those of cells that were not so activated. On the population level only neurons activated from the NOT-DTN had a clear preference for ipsiversive stimulus movement, whereas the neurons activated from the DLPN and neurons not antidromically activated from either target had no common directional preference. These results are discussed in terms of specification of cortico-subcortical connections and with regard to pathways underlying slow eye movements in different visuomotor behaviours.

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“…The head is restrained (thus excluding the vestibular contribution) and a checkerboard pattern mimicking the background is displaced in front of the animal. Direction-selective neurons with a bias toward ipsoversive movement of the visual background have been found in several mammals, including the rabbit (Collewijn 1975b), rat (Cazin et al 1980b), cat (Hoffmann and Schoppmann 1981), monkey (Hoffmann et al 1988), ferret (Klauer et al 1990), and wallaby (Ibbotson et al 1994); they are also present in the opossum's NOT (Volchan et al 1989, Pereira et al 1994. A rightward movement of the visual stimulus causes simultaneous excitation of the right NOT and inhibition of the left NOT, with the activity reversing when the stimulus moves horizontally to the left (figure 2).…”

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confidence: 99%

“…Our studies have focused on the nucleus of the optic tract, or NOT (Volchan et al 1989, Pereira et al 1994, 1998, 2001, which detects the horizontal wavering of the retinal image and generates, through several steps downstream, a compensatory eye movement called the horizontal optokinetic reflex. In this article we review the functional and anatomical data for the circuitry underlying the horizontal optokinetic reflex and propose that it is well suited to provide this species with a framework to stabilize the retinal image while the opossum forages for food.…”

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confidence: 99%