Limits...
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 rotation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the planetarium projector used to simulate rotational optic flow. (B) Shows the elevation tuning curve for a vertical axis (VA) neuron. The flowfield that maximally stimulates VA neurons shown in (C), and the best axes of several VA neurons are shown in (D). (E–G) Shows axis tuning for an HA neuron. (F) Shows an azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane. (G) Shows an azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c). The flowfield that maximally stimulates HA neurons in shown in (H), and the best axes of several HA neurons are shown in (I). (J) Shows the reference frame for rotational optic flow responses in the VbC. Considering both sides of the brain, it consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. All responses in this and subsequent figures refer to recording from neurons in the VbC on the left side of the brain. These data are from Wylie and Frost (1993). See text for additional details.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3569843&req=5

Figure 4: Stimulating rotation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the planetarium projector used to simulate rotational optic flow. (B) Shows the elevation tuning curve for a vertical axis (VA) neuron. The flowfield that maximally stimulates VA neurons shown in (C), and the best axes of several VA neurons are shown in (D). (E–G) Shows axis tuning for an HA neuron. (F) Shows an azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane. (G) Shows an azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c). The flowfield that maximally stimulates HA neurons in shown in (H), and the best axes of several HA neurons are shown in (I). (J) Shows the reference frame for rotational optic flow responses in the VbC. Considering both sides of the brain, it consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. All responses in this and subsequent figures refer to recording from neurons in the VbC on the left side of the brain. These data are from Wylie and Frost (1993). See text for additional details.

Mentions: To provide an effective stimulus for neurons responsive to rotational optic flow in the flocculus of rabbits, Jerry Simpson and Werner Graf designed a planetarium projector, which projected a flowfield onto the floor, walls and ceiling of the room (Simpson et al., 1981, 1988). The projector was suspended in gimbals, such that axis of rotation could be aligned to any orientation within 3-dimensional space. We used a similar device, depicted in Figure 4A, to stimulate the complex spike activity of Purkinje cells in the pigeon flocculus. Our findings (Wylie and Frost, 1993) were essentially identical to those of Graf et al. (1988). In the flocculus, there are two types of neurons: one prefers rotational optic flow about the vertical (y) axis (VA neurons) and the other prefers rotational optic flow about an horizontal axis oriented 45° to the midline (HA neurons). Figure 4B shows the responses of a VA neuron in the left flocculus to rotational optic flow about four axes in the sagittal (yz) plane. Each peri-stimulus time histogram (PSTH) is summed from 10 sweeps, where each sweep consisted of 5 s of rotation in one direction followed by 5 s of rotation in the opposite direction. An elevation tuning curve is also shown, where the firing rate (solid red line) is plotted as a function of the axis of rotation. The broken circle represents the spontaneous rate, and the broken red line indicates the preferred axis as calculated from the best fit sine wave. The direction of each curved arrow represents the direction of head motion that would cause the presented flowfield. Thus, the cell responds best to leftward rotation of the head about the vertical (y) axis. The flowfield that maximally stimulates VA neurons in shown in Figure 4C, and the best axes of several VA neurons are shown in Figure 4D. The largest arrow with the broken shaft represents the mean of the distribution. Figures 4E–G shows axis tuning for an HA neuron. Figure 4F shows the azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane, whereas Figure 4G shows the azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c) for the same neurons. This vertical plane is depicted in Figure 4E, and the axes numbered 1–4 in Figure 4E correspond to those in Figure 4G. This neuron responded best to rotation about an horizontal axis oriented at 45°c/135°i azimuth. The flowfield that maximally stimulates HA neurons in shown in Figure 4H, and the best axes of several HA neurons are shown in Figure 4I.


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

Wylie DR - Front Behav Neurosci (2013)

Stimulating rotation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the planetarium projector used to simulate rotational optic flow. (B) Shows the elevation tuning curve for a vertical axis (VA) neuron. The flowfield that maximally stimulates VA neurons shown in (C), and the best axes of several VA neurons are shown in (D). (E–G) Shows axis tuning for an HA neuron. (F) Shows an azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane. (G) Shows an azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c). The flowfield that maximally stimulates HA neurons in shown in (H), and the best axes of several HA neurons are shown in (I). (J) Shows the reference frame for rotational optic flow responses in the VbC. Considering both sides of the brain, it consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. All responses in this and subsequent figures refer to recording from neurons in the VbC on the left side of the brain. These data are from Wylie and Frost (1993). See text for additional details.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569843&req=5

Figure 4: Stimulating rotation-sensitive optic flow neurons in the pigeon vestibulocerebellum (VbC). (A) Shows a schematic of the planetarium projector used to simulate rotational optic flow. (B) Shows the elevation tuning curve for a vertical axis (VA) neuron. The flowfield that maximally stimulates VA neurons shown in (C), and the best axes of several VA neurons are shown in (D). (E–G) Shows axis tuning for an HA neuron. (F) Shows an azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane. (G) Shows an azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c). The flowfield that maximally stimulates HA neurons in shown in (H), and the best axes of several HA neurons are shown in (I). (J) Shows the reference frame for rotational optic flow responses in the VbC. Considering both sides of the brain, it consists of three orthogonal axes: the vertical (y) axis and two horizontal axes oriented 45° to the midline. All responses in this and subsequent figures refer to recording from neurons in the VbC on the left side of the brain. These data are from Wylie and Frost (1993). See text for additional details.
Mentions: To provide an effective stimulus for neurons responsive to rotational optic flow in the flocculus of rabbits, Jerry Simpson and Werner Graf designed a planetarium projector, which projected a flowfield onto the floor, walls and ceiling of the room (Simpson et al., 1981, 1988). The projector was suspended in gimbals, such that axis of rotation could be aligned to any orientation within 3-dimensional space. We used a similar device, depicted in Figure 4A, to stimulate the complex spike activity of Purkinje cells in the pigeon flocculus. Our findings (Wylie and Frost, 1993) were essentially identical to those of Graf et al. (1988). In the flocculus, there are two types of neurons: one prefers rotational optic flow about the vertical (y) axis (VA neurons) and the other prefers rotational optic flow about an horizontal axis oriented 45° to the midline (HA neurons). Figure 4B shows the responses of a VA neuron in the left flocculus to rotational optic flow about four axes in the sagittal (yz) plane. Each peri-stimulus time histogram (PSTH) is summed from 10 sweeps, where each sweep consisted of 5 s of rotation in one direction followed by 5 s of rotation in the opposite direction. An elevation tuning curve is also shown, where the firing rate (solid red line) is plotted as a function of the axis of rotation. The broken circle represents the spontaneous rate, and the broken red line indicates the preferred axis as calculated from the best fit sine wave. The direction of each curved arrow represents the direction of head motion that would cause the presented flowfield. Thus, the cell responds best to leftward rotation of the head about the vertical (y) axis. The flowfield that maximally stimulates VA neurons in shown in Figure 4C, and the best axes of several VA neurons are shown in Figure 4D. The largest arrow with the broken shaft represents the mean of the distribution. Figures 4E–G shows axis tuning for an HA neuron. Figure 4F shows the azimuth tuning curve plotting the responses to rotation about axes in the horizontal (xz) plane, whereas Figure 4G shows the azimuth tuning curve in a vertical plane that intersects the horizontal plane through 45° contralateral azimuth (45°c) for the same neurons. This vertical plane is depicted in Figure 4E, and the axes numbered 1–4 in Figure 4E correspond to those in Figure 4G. This neuron responded best to rotation about an horizontal axis oriented at 45°c/135°i azimuth. The flowfield that maximally stimulates HA neurons in shown in Figure 4H, and the best axes of several HA neurons are shown in Figure 4I.

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