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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

Mossy fiber projections to the posterior cerebellum. From an injection of green LumaFluor in folium VII, retrogradely labeled cells were found in the medial subnucleus of lentiformis mesencephali (LMm) (A) and the potine nuclei (B). From an injection of red LumaFluor in folium IXcd, cells were labeled in nBOR (not shown) and the lateral subnucleus of LM (A). (C) Shows the relative proportion of cells labeled in LMm (gray bars) and LMl (black bars) from injections in IXcd (left) and folia VI–VIII (right), collapsed from several cases. (D) Shows how in VI–VIII there is an integration of optic flow information, from LMm, with local motion information from a tecto-pontine system. From Pakan and Wylie (2006). LMi: intercalated subnucleus of LM. Scale bars: (A,B) = 100 μm.
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Figure 11: Mossy fiber projections to the posterior cerebellum. From an injection of green LumaFluor in folium VII, retrogradely labeled cells were found in the medial subnucleus of lentiformis mesencephali (LMm) (A) and the potine nuclei (B). From an injection of red LumaFluor in folium IXcd, cells were labeled in nBOR (not shown) and the lateral subnucleus of LM (A). (C) Shows the relative proportion of cells labeled in LMm (gray bars) and LMl (black bars) from injections in IXcd (left) and folia VI–VIII (right), collapsed from several cases. (D) Shows how in VI–VIII there is an integration of optic flow information, from LMm, with local motion information from a tecto-pontine system. From Pakan and Wylie (2006). LMi: intercalated subnucleus of LM. Scale bars: (A,B) = 100 μm.

Mentions: In addition to the projection to IXcd, the LM also projects heavily to folia VI–VIII (Clarke, 1977), which is known as the oculomotor cerebellum (Voogd and Barmack, 2006). Pakan et al. (2006) investigated this projection using retrograde techniques. After injections of tracer into folia VI–VIII, most retrogradely labeled cells were found in LMm, whereas injections into IXcd labeled more cells in LMl (Figure 11). Injections into VI–VIII also labeled cells in the medial and lateral pontine nuclei. Previous reports have shown that the optic tectum projects to the pontine nuclei (Reiner and Karten, 1982). Thus, it appears that local motion from the tectum, and optic flow from LM may be integrated in the posterior cerebellum. What could be the function of this visual-visual integration? A few studies have shown that there is integration of local and optic flow information in primate visual cortex, and it has been suggested that this is important for “steering” to avoid obstacles during locomotion through cluttered environments (Page and Duffy, 2008; Elder et al., 2009). Hellmann et al. (2004) have suggested that the tecto-pontine pathway in birds is involved in avoidance behavior. Thus, perhaps the integration of optic flow and local motion signals in the posterior cerebellum of birds is important for obstacle avoidance as they fly through cluttered environments.


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

Wylie DR - Front Behav Neurosci (2013)

Mossy fiber projections to the posterior cerebellum. From an injection of green LumaFluor in folium VII, retrogradely labeled cells were found in the medial subnucleus of lentiformis mesencephali (LMm) (A) and the potine nuclei (B). From an injection of red LumaFluor in folium IXcd, cells were labeled in nBOR (not shown) and the lateral subnucleus of LM (A). (C) Shows the relative proportion of cells labeled in LMm (gray bars) and LMl (black bars) from injections in IXcd (left) and folia VI–VIII (right), collapsed from several cases. (D) Shows how in VI–VIII there is an integration of optic flow information, from LMm, with local motion information from a tecto-pontine system. From Pakan and Wylie (2006). LMi: intercalated subnucleus of LM. Scale bars: (A,B) = 100 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 11: Mossy fiber projections to the posterior cerebellum. From an injection of green LumaFluor in folium VII, retrogradely labeled cells were found in the medial subnucleus of lentiformis mesencephali (LMm) (A) and the potine nuclei (B). From an injection of red LumaFluor in folium IXcd, cells were labeled in nBOR (not shown) and the lateral subnucleus of LM (A). (C) Shows the relative proportion of cells labeled in LMm (gray bars) and LMl (black bars) from injections in IXcd (left) and folia VI–VIII (right), collapsed from several cases. (D) Shows how in VI–VIII there is an integration of optic flow information, from LMm, with local motion information from a tecto-pontine system. From Pakan and Wylie (2006). LMi: intercalated subnucleus of LM. Scale bars: (A,B) = 100 μm.
Mentions: In addition to the projection to IXcd, the LM also projects heavily to folia VI–VIII (Clarke, 1977), which is known as the oculomotor cerebellum (Voogd and Barmack, 2006). Pakan et al. (2006) investigated this projection using retrograde techniques. After injections of tracer into folia VI–VIII, most retrogradely labeled cells were found in LMm, whereas injections into IXcd labeled more cells in LMl (Figure 11). Injections into VI–VIII also labeled cells in the medial and lateral pontine nuclei. Previous reports have shown that the optic tectum projects to the pontine nuclei (Reiner and Karten, 1982). Thus, it appears that local motion from the tectum, and optic flow from LM may be integrated in the posterior cerebellum. What could be the function of this visual-visual integration? A few studies have shown that there is integration of local and optic flow information in primate visual cortex, and it has been suggested that this is important for “steering” to avoid obstacles during locomotion through cluttered environments (Page and Duffy, 2008; Elder et al., 2009). Hellmann et al. (2004) have suggested that the tecto-pontine pathway in birds is involved in avoidance behavior. Thus, perhaps the integration of optic flow and local motion signals in the posterior cerebellum of birds is important for obstacle avoidance as they fly through cluttered environments.

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