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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

(A) and (B), Respectively, show receptive fields either “precisely” tuned for rotational optic flow by pooling many local motion detectors with different direction preferences, or “approximately” tuned with a bipartite receptive field structure. (C) Shows the responses of an HA neuron to composite stimuli. The neuron responded much better to vertical shear as opposed to horizontal shear, indicating that it has a bipartite receptive field structure shown in (B) (Winship and Wylie, 2006). (D) Shows the normalized depth of modulation [(CCW−CW)/(CCW+CW)] for all rotation units (n = 22) in response to the three stimulus configurations illustrated (mean ± s.e.m). Note that the cells responded better to the vertical shear as opposed to the true rotation (Winship and Wylie, 2006). (E) Shows the responses of a rotation sensitive neuron in monkey area MST to similar stimuli. It responded equally well to vertical and horizontal shear, indicating that it has a precisely tuned receptive field (from Tanaka and Saito, 1989). (F) Shows the responses of an optic flow neuron in the lobula plate in blowflies to local stimulation. These neurons have an underlying receptive field with precise tuning (from Krapp et al., 1998).
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Figure 6: (A) and (B), Respectively, show receptive fields either “precisely” tuned for rotational optic flow by pooling many local motion detectors with different direction preferences, or “approximately” tuned with a bipartite receptive field structure. (C) Shows the responses of an HA neuron to composite stimuli. The neuron responded much better to vertical shear as opposed to horizontal shear, indicating that it has a bipartite receptive field structure shown in (B) (Winship and Wylie, 2006). (D) Shows the normalized depth of modulation [(CCW−CW)/(CCW+CW)] for all rotation units (n = 22) in response to the three stimulus configurations illustrated (mean ± s.e.m). Note that the cells responded better to the vertical shear as opposed to the true rotation (Winship and Wylie, 2006). (E) Shows the responses of a rotation sensitive neuron in monkey area MST to similar stimuli. It responded equally well to vertical and horizontal shear, indicating that it has a precisely tuned receptive field (from Tanaka and Saito, 1989). (F) Shows the responses of an optic flow neuron in the lobula plate in blowflies to local stimulation. These neurons have an underlying receptive field with precise tuning (from Krapp et al., 1998).

Mentions: Figure 6A depicts the flowfield that would result from a rightward rotation about the roll axis. To construct a receptive field sensitive to this flowfield, one could pool information from local motion detectors with predictably varying direction preferences: leftward/downward at S1, downward at S2, upward at S3, etc. This is not the case for the optic flow cells in the VbC. Rather they have a receptive field structure that provides a crude approximation to the preferred optic flow pattern by pooling information from two motion detectors with opposing direction preferences as illustrated in Figure 6B. Such a “bipartite” receptive field was suggested by Simpson et al. (1979, 1981, 1988) for the HA neurons in the rabbit flocculus. Winship and Wylie (2006) showed that the bipartitie receptive field type of arrangement underlies the receptive field structure for neurons in the pigeon flocculus and uvula/nodulus. Figure 6C shows some of the critical data for an HA neuron in the pigeon flocculus. The cell was stimulated with the two composite stimuli depicted. We predicted that if the receptive field was precisely tuned to rotation (as in Figure 6A), the cell would modulate equally to the “horizontal shear” and “vertical shear” conditions as an equal number of motion detectors would be excited by both stimulus configurations. However, the cell showed maximal modulation to the vertical shear configuration and no modulation to the horizontal shear condition, indicating the underlying receptive field is bipartite as indicated in Figure 6B. Data for all (n = 22) flocculus HA neurons are shown in Figure 6D. Here the normalized depth of modulation is shown in response to the vertical and horizontal shear stimuli, as well as true rotation. Note that the cells showed little modulation to the horizontal shear, and more to the vertical shear compared to rotation. Again, these data support the idea of a bipartite receptive field organization.


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

Wylie DR - Front Behav Neurosci (2013)

(A) and (B), Respectively, show receptive fields either “precisely” tuned for rotational optic flow by pooling many local motion detectors with different direction preferences, or “approximately” tuned with a bipartite receptive field structure. (C) Shows the responses of an HA neuron to composite stimuli. The neuron responded much better to vertical shear as opposed to horizontal shear, indicating that it has a bipartite receptive field structure shown in (B) (Winship and Wylie, 2006). (D) Shows the normalized depth of modulation [(CCW−CW)/(CCW+CW)] for all rotation units (n = 22) in response to the three stimulus configurations illustrated (mean ± s.e.m). Note that the cells responded better to the vertical shear as opposed to the true rotation (Winship and Wylie, 2006). (E) Shows the responses of a rotation sensitive neuron in monkey area MST to similar stimuli. It responded equally well to vertical and horizontal shear, indicating that it has a precisely tuned receptive field (from Tanaka and Saito, 1989). (F) Shows the responses of an optic flow neuron in the lobula plate in blowflies to local stimulation. These neurons have an underlying receptive field with precise tuning (from Krapp et al., 1998).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: (A) and (B), Respectively, show receptive fields either “precisely” tuned for rotational optic flow by pooling many local motion detectors with different direction preferences, or “approximately” tuned with a bipartite receptive field structure. (C) Shows the responses of an HA neuron to composite stimuli. The neuron responded much better to vertical shear as opposed to horizontal shear, indicating that it has a bipartite receptive field structure shown in (B) (Winship and Wylie, 2006). (D) Shows the normalized depth of modulation [(CCW−CW)/(CCW+CW)] for all rotation units (n = 22) in response to the three stimulus configurations illustrated (mean ± s.e.m). Note that the cells responded better to the vertical shear as opposed to the true rotation (Winship and Wylie, 2006). (E) Shows the responses of a rotation sensitive neuron in monkey area MST to similar stimuli. It responded equally well to vertical and horizontal shear, indicating that it has a precisely tuned receptive field (from Tanaka and Saito, 1989). (F) Shows the responses of an optic flow neuron in the lobula plate in blowflies to local stimulation. These neurons have an underlying receptive field with precise tuning (from Krapp et al., 1998).
Mentions: Figure 6A depicts the flowfield that would result from a rightward rotation about the roll axis. To construct a receptive field sensitive to this flowfield, one could pool information from local motion detectors with predictably varying direction preferences: leftward/downward at S1, downward at S2, upward at S3, etc. This is not the case for the optic flow cells in the VbC. Rather they have a receptive field structure that provides a crude approximation to the preferred optic flow pattern by pooling information from two motion detectors with opposing direction preferences as illustrated in Figure 6B. Such a “bipartite” receptive field was suggested by Simpson et al. (1979, 1981, 1988) for the HA neurons in the rabbit flocculus. Winship and Wylie (2006) showed that the bipartitie receptive field type of arrangement underlies the receptive field structure for neurons in the pigeon flocculus and uvula/nodulus. Figure 6C shows some of the critical data for an HA neuron in the pigeon flocculus. The cell was stimulated with the two composite stimuli depicted. We predicted that if the receptive field was precisely tuned to rotation (as in Figure 6A), the cell would modulate equally to the “horizontal shear” and “vertical shear” conditions as an equal number of motion detectors would be excited by both stimulus configurations. However, the cell showed maximal modulation to the vertical shear configuration and no modulation to the horizontal shear condition, indicating the underlying receptive field is bipartite as indicated in Figure 6B. Data for all (n = 22) flocculus HA neurons are shown in Figure 6D. Here the normalized depth of modulation is shown in response to the vertical and horizontal shear stimuli, as well as true rotation. Note that the cells showed little modulation to the horizontal shear, and more to the vertical shear compared to rotation. Again, these data support the idea of a bipartite receptive field organization.

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