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Processing of visual signals related to self-motion in the cerebellum of pigeons.

Wylie DR - Front Behav Neurosci (2013)

Bottom Line: Optic flow is the visual motion that occurs across the entire retina as a result of self-motion and is processed by subcortical visual pathways that project to the cerebellum.As the tectofugal system is involved in the analysis of local motion, there is integration of optic flow and local motion information in VI-VIII.This part of the cerebellum may be important for moving through a cluttered environment.

View Article: PubMed Central - PubMed

Affiliation: Centre for Neuroscience and Department of Psychology, University of Alberta Edmonton, AB, Canada.

ABSTRACT
In this paper I describe the key features of optic flow processing in pigeons. Optic flow is the visual motion that occurs across the entire retina as a result of self-motion and is processed by subcortical visual pathways that project to the cerebellum. These pathways originate in two retinal-recipient nuclei, the nucleus of the basal optic root (nBOR) and the nucleus lentiformis mesencephali, which project to the vestibulocerebellum (VbC) (folia IXcd and X), directly as mossy fibers, and indirectly as climbing fibers from the inferior olive. Optic flow information is integrated with vestibular input in the VbC. There is a clear separation of function in the VbC: Purkinje cells in the flocculus process optic flow resulting from self-rotation, whereas Purkinje cells in the uvula/nodulus process optic flow resulting from self-translation. Furthermore, Purkinje cells with particular optic flow preferences are organized topographically into parasagittal "zones." These zones are correlated with expression of the isoenzyme aldolase C, also known as zebrin II (ZII). ZII expression is heterogeneous such that there are parasagittal stripes of Purkinje cells that have high expression (ZII+) alternating with stripes of Purkinje cells with low expression (ZII-). A functional zone spans a ZII± stripe pair. That is, each zone that contains Purkinje cells responsive to a particular pattern of optic flow is subdivided into a strip containing ZII+ Purkinje cells and a strip containing ZII- Purkinje cells. Additionally, there is optic flow input to folia VI-VIII of the cerebellum from lentiformis mesencephali. These folia also receive visual input from the tectofugal system via pontine nuclei. As the tectofugal system is involved in the analysis of local motion, there is integration of optic flow and local motion information in VI-VIII. This part of the cerebellum may be important for moving through a cluttered environment.

No MeSH data available.


Related in: MedlinePlus

Stimulating translation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the translator projector used to simulate translational optic flow. This was suspended above the bird's head in gimbals such that the axis of translation could be oriented anywhere in 3-dimensional space. (B) Shows the responses of a Contraction neuron. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal plane at 45°c azimuth. (C–E) Show tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in (F), and the best axes of translation for the four groups are shown in (G). (H) Shows the common reference frame for translational and rotational optic flow reponses in the VbC. The data are from Wylie and Frost (1999b). See text for additional details.
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Figure 5: Stimulating translation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the translator projector used to simulate translational optic flow. This was suspended above the bird's head in gimbals such that the axis of translation could be oriented anywhere in 3-dimensional space. (B) Shows the responses of a Contraction neuron. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal plane at 45°c azimuth. (C–E) Show tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in (F), and the best axes of translation for the four groups are shown in (G). (H) Shows the common reference frame for translational and rotational optic flow reponses in the VbC. The data are from Wylie and Frost (1999b). See text for additional details.

Mentions: To simulate translational optic flow we designed the device shown in Figure 5A, which projected panoramic translational optic flow on to the walls, ceiling, and floor of the room, and we recorded from Purkinje cells in the uvula/nodulus in pigeons (Wylie et al., 1998a; Wylie and Frost, 1999a). There are four types of optic flow neurons in the uvula/nodulus: Contraction, Expansion, Ascent, and Descent. Figure 5B shows the responses of a Contraction neuron in the left uvula/nodulus in response to translational optic flow along several axes. PSTHs show the responses to translational optic flow along 4 axes in the horizontal (xz) plane. Each PSTH is summed from 20 sweeps, where each sweep consisted of 5 s of translation in one direction followed by a 5 s pause, then 5 s of motion in the opposite direction followed by a 5 s pause. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal place at 45°c azimuth. The direction of each arrow represents the direction of head motion that would cause the presented flowfield. This cell responds best to backward translation along an horizontal axis oriented at 45°c/135°i azimuth. This results in a flowfield with a focus of contraction at 45°c azimuth. Figures 5C–E shows tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in Figure 5F, and the best axes of translation for the four groups are shown in Figure 5G. Figure 5H shows the common reference frame for translational and rotational optic flow responses in the VbC. Considering both sides of the brain, the reference frame consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. Note that this is the same reference frame as that of the rotational optic flow system in the flocculus. We have previously argued how this reference frame is optimal on several accounts (see Frost and Wylie, 2000).


Processing of visual signals related to self-motion in the cerebellum of pigeons.

Wylie DR - Front Behav Neurosci (2013)

Stimulating translation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the translator projector used to simulate translational optic flow. This was suspended above the bird's head in gimbals such that the axis of translation could be oriented anywhere in 3-dimensional space. (B) Shows the responses of a Contraction neuron. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal plane at 45°c azimuth. (C–E) Show tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in (F), and the best axes of translation for the four groups are shown in (G). (H) Shows the common reference frame for translational and rotational optic flow reponses in the VbC. The data are from Wylie and Frost (1999b). See text for additional details.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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Figure 5: Stimulating translation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the translator projector used to simulate translational optic flow. This was suspended above the bird's head in gimbals such that the axis of translation could be oriented anywhere in 3-dimensional space. (B) Shows the responses of a Contraction neuron. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal plane at 45°c azimuth. (C–E) Show tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in (F), and the best axes of translation for the four groups are shown in (G). (H) Shows the common reference frame for translational and rotational optic flow reponses in the VbC. The data are from Wylie and Frost (1999b). See text for additional details.
Mentions: To simulate translational optic flow we designed the device shown in Figure 5A, which projected panoramic translational optic flow on to the walls, ceiling, and floor of the room, and we recorded from Purkinje cells in the uvula/nodulus in pigeons (Wylie et al., 1998a; Wylie and Frost, 1999a). There are four types of optic flow neurons in the uvula/nodulus: Contraction, Expansion, Ascent, and Descent. Figure 5B shows the responses of a Contraction neuron in the left uvula/nodulus in response to translational optic flow along several axes. PSTHs show the responses to translational optic flow along 4 axes in the horizontal (xz) plane. Each PSTH is summed from 20 sweeps, where each sweep consisted of 5 s of translation in one direction followed by a 5 s pause, then 5 s of motion in the opposite direction followed by a 5 s pause. An azimuth tuning curve (xz plane) is shown as well as an elevation tuning curve in a vertical plane that intersects the horizontal place at 45°c azimuth. The direction of each arrow represents the direction of head motion that would cause the presented flowfield. This cell responds best to backward translation along an horizontal axis oriented at 45°c/135°i azimuth. This results in a flowfield with a focus of contraction at 45°c azimuth. Figures 5C–E shows tuning curves for the other three types of translation neurons in the VbC: Descent, Ascent and Expansion. The flowfields that maximally stimulate each of the four types are shown in Figure 5F, and the best axes of translation for the four groups are shown in Figure 5G. Figure 5H shows the common reference frame for translational and rotational optic flow responses in the VbC. Considering both sides of the brain, the reference frame consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. Note that this is the same reference frame as that of the rotational optic flow system in the flocculus. We have previously argued how this reference frame is optimal on several accounts (see Frost and Wylie, 2000).

Bottom Line: Optic flow is the visual motion that occurs across the entire retina as a result of self-motion and is processed by subcortical visual pathways that project to the cerebellum.As the tectofugal system is involved in the analysis of local motion, there is integration of optic flow and local motion information in VI-VIII.This part of the cerebellum may be important for moving through a cluttered environment.

View Article: PubMed Central - PubMed

Affiliation: Centre for Neuroscience and Department of Psychology, University of Alberta Edmonton, AB, Canada.

ABSTRACT
In this paper I describe the key features of optic flow processing in pigeons. Optic flow is the visual motion that occurs across the entire retina as a result of self-motion and is processed by subcortical visual pathways that project to the cerebellum. These pathways originate in two retinal-recipient nuclei, the nucleus of the basal optic root (nBOR) and the nucleus lentiformis mesencephali, which project to the vestibulocerebellum (VbC) (folia IXcd and X), directly as mossy fibers, and indirectly as climbing fibers from the inferior olive. Optic flow information is integrated with vestibular input in the VbC. There is a clear separation of function in the VbC: Purkinje cells in the flocculus process optic flow resulting from self-rotation, whereas Purkinje cells in the uvula/nodulus process optic flow resulting from self-translation. Furthermore, Purkinje cells with particular optic flow preferences are organized topographically into parasagittal "zones." These zones are correlated with expression of the isoenzyme aldolase C, also known as zebrin II (ZII). ZII expression is heterogeneous such that there are parasagittal stripes of Purkinje cells that have high expression (ZII+) alternating with stripes of Purkinje cells with low expression (ZII-). A functional zone spans a ZII± stripe pair. That is, each zone that contains Purkinje cells responsive to a particular pattern of optic flow is subdivided into a strip containing ZII+ Purkinje cells and a strip containing ZII- Purkinje cells. Additionally, there is optic flow input to folia VI-VIII of the cerebellum from lentiformis mesencephali. These folia also receive visual input from the tectofugal system via pontine nuclei. As the tectofugal system is involved in the analysis of local motion, there is integration of optic flow and local motion information in VI-VIII. This part of the cerebellum may be important for moving through a cluttered environment.

No MeSH data available.


Related in: MedlinePlus