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A simpler primate brain: the visual system of the marmoset monkey.

Solomon SG, Rosa MG - Front Neural Circuits (2014)

Bottom Line: Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains.Which species is the most appropriate model?Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Psychology, University College London London, UK.

ABSTRACT
Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect to the organization of the cerebral cortex. Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains. Which species is the most appropriate model? Macaque monkeys, the most widely used non-human primates, are not an optimal choice in many practical respects. For example, much of the macaque cerebral cortex is buried within sulci, and is therefore inaccessible to many imaging techniques, and the postnatal development and lifespan of macaques are prohibitively long for many studies of brain maturation, plasticity, and aging. In these and several other respects the marmoset, a small New World monkey, represents a more appropriate choice. Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans. We will argue that the marmoset monkey provides a good subject for studies of a complex visual system, which will likely allow an important bridge linking experiments in animal models to humans.

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Lateral (left) and medial (right) views of the marmoset cerebral cortex, showing the location of visual areas. The images are representations of the reference brain reconstructed in detail by Paxinos et al. (2012). Names within parentheses indicate the names of likely homologous areas in macaque brain. Colors denote different subdivisions of visual cortical pathways, as follows. Magenta: primary visual cortical area (V1). Pink: visuotopically organized areas of extrastriate cortex. Green: posterior parietal cortex. Dark blue: inferior temporal cortex. Light blue: polysensory areas of the superior temporal cortex. Orange: “limbic” visual areas. Yellow: frontal cortex visual association areas, including frontal eye fields. Abbreviations: 8aV, cytoarchitectural area 8a ventral; 23V, cytoarchitectural area 23 ventral; AIP, anterior intraparietal area; DA, dorsoanterior area (probable homolog of macaque area V3a); DI, dorsointermediate area; DM, dorsomedial area (probable homolog of macaque area V6); FST, fundus of superior temporal area; FSTv, fundus of superior temporal ventral area (probable homolog of macaque cytoarchitectural areas PGa and IPa); ITc, caudal inferior temporal area (probable homolog of macaque area TEO); ITd, dorsal inferior temporal area; ITv, ventral inferior temporal area; LIP, lateral intraparietal area; MIP, medial intraparietal area; MST, medial superior temporal area; MT, middle temporal area (probable homolog of macaque area V5); MTC, middle temporal crescent (probable homolog of macaque area V4T); OPt, cytoarchitectural area OPt; PEC, cytoarchitectural area PE caudal; PG, cytoarchitectural area PG; PGM, cytoarchitectural area PG medial; PPM, posterior parietal medial area (probable homolog of macaque area V6a); ProSt, area prostriata; STP, superior temporal polysensory area (probable homolog of macaque cytoarchitectural area TPO); TF/ TL, cytoarchitectural areas TF and TL; V1, primary visual area; V2, second visual area; VIP, ventral intraparietal area; VLA, ventrolateral anterior area (probable homolog of macaque area V4); VLP, ventrolateral posterior area (probable homolog of macaque area V3).
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Figure 1: Lateral (left) and medial (right) views of the marmoset cerebral cortex, showing the location of visual areas. The images are representations of the reference brain reconstructed in detail by Paxinos et al. (2012). Names within parentheses indicate the names of likely homologous areas in macaque brain. Colors denote different subdivisions of visual cortical pathways, as follows. Magenta: primary visual cortical area (V1). Pink: visuotopically organized areas of extrastriate cortex. Green: posterior parietal cortex. Dark blue: inferior temporal cortex. Light blue: polysensory areas of the superior temporal cortex. Orange: “limbic” visual areas. Yellow: frontal cortex visual association areas, including frontal eye fields. Abbreviations: 8aV, cytoarchitectural area 8a ventral; 23V, cytoarchitectural area 23 ventral; AIP, anterior intraparietal area; DA, dorsoanterior area (probable homolog of macaque area V3a); DI, dorsointermediate area; DM, dorsomedial area (probable homolog of macaque area V6); FST, fundus of superior temporal area; FSTv, fundus of superior temporal ventral area (probable homolog of macaque cytoarchitectural areas PGa and IPa); ITc, caudal inferior temporal area (probable homolog of macaque area TEO); ITd, dorsal inferior temporal area; ITv, ventral inferior temporal area; LIP, lateral intraparietal area; MIP, medial intraparietal area; MST, medial superior temporal area; MT, middle temporal area (probable homolog of macaque area V5); MTC, middle temporal crescent (probable homolog of macaque area V4T); OPt, cytoarchitectural area OPt; PEC, cytoarchitectural area PE caudal; PG, cytoarchitectural area PG; PGM, cytoarchitectural area PG medial; PPM, posterior parietal medial area (probable homolog of macaque area V6a); ProSt, area prostriata; STP, superior temporal polysensory area (probable homolog of macaque cytoarchitectural area TPO); TF/ TL, cytoarchitectural areas TF and TL; V1, primary visual area; V2, second visual area; VIP, ventral intraparietal area; VLA, ventrolateral anterior area (probable homolog of macaque area V4); VLP, ventrolateral posterior area (probable homolog of macaque area V3).

Mentions: Figure 1 illustrates the external morphology of the marmoset brain, with visual and visual association cortical areas highlighted. The marmoset brain (∼8 g) is approximately 12 times smaller in volume than that of the rhesus macaque, and 180 times smaller than the human brain (Stephan et al., 1981). Figure 1 readily conveys one of the key advantages of the marmoset as a model for studies of the visual system: the relatively smooth topology of the cerebral cortex. Thus, in marmosets the vast majority of the visual cortex lies exposed on the surface of the cerebral hemispheres. The only known exceptions are those portions of visual cortex buried in the banks of the calcarine sulcus: that is, the representation of the peripheral visual field in the primary visual cortex (V1; Fritsches and Rosa, 1996), small sectors of the peripheral representation in the second visual area (V2; Rosa et al., 1997), and area prostriata (Yu et al., 2012).


A simpler primate brain: the visual system of the marmoset monkey.

Solomon SG, Rosa MG - Front Neural Circuits (2014)

Lateral (left) and medial (right) views of the marmoset cerebral cortex, showing the location of visual areas. The images are representations of the reference brain reconstructed in detail by Paxinos et al. (2012). Names within parentheses indicate the names of likely homologous areas in macaque brain. Colors denote different subdivisions of visual cortical pathways, as follows. Magenta: primary visual cortical area (V1). Pink: visuotopically organized areas of extrastriate cortex. Green: posterior parietal cortex. Dark blue: inferior temporal cortex. Light blue: polysensory areas of the superior temporal cortex. Orange: “limbic” visual areas. Yellow: frontal cortex visual association areas, including frontal eye fields. Abbreviations: 8aV, cytoarchitectural area 8a ventral; 23V, cytoarchitectural area 23 ventral; AIP, anterior intraparietal area; DA, dorsoanterior area (probable homolog of macaque area V3a); DI, dorsointermediate area; DM, dorsomedial area (probable homolog of macaque area V6); FST, fundus of superior temporal area; FSTv, fundus of superior temporal ventral area (probable homolog of macaque cytoarchitectural areas PGa and IPa); ITc, caudal inferior temporal area (probable homolog of macaque area TEO); ITd, dorsal inferior temporal area; ITv, ventral inferior temporal area; LIP, lateral intraparietal area; MIP, medial intraparietal area; MST, medial superior temporal area; MT, middle temporal area (probable homolog of macaque area V5); MTC, middle temporal crescent (probable homolog of macaque area V4T); OPt, cytoarchitectural area OPt; PEC, cytoarchitectural area PE caudal; PG, cytoarchitectural area PG; PGM, cytoarchitectural area PG medial; PPM, posterior parietal medial area (probable homolog of macaque area V6a); ProSt, area prostriata; STP, superior temporal polysensory area (probable homolog of macaque cytoarchitectural area TPO); TF/ TL, cytoarchitectural areas TF and TL; V1, primary visual area; V2, second visual area; VIP, ventral intraparietal area; VLA, ventrolateral anterior area (probable homolog of macaque area V4); VLP, ventrolateral posterior area (probable homolog of macaque area V3).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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Figure 1: Lateral (left) and medial (right) views of the marmoset cerebral cortex, showing the location of visual areas. The images are representations of the reference brain reconstructed in detail by Paxinos et al. (2012). Names within parentheses indicate the names of likely homologous areas in macaque brain. Colors denote different subdivisions of visual cortical pathways, as follows. Magenta: primary visual cortical area (V1). Pink: visuotopically organized areas of extrastriate cortex. Green: posterior parietal cortex. Dark blue: inferior temporal cortex. Light blue: polysensory areas of the superior temporal cortex. Orange: “limbic” visual areas. Yellow: frontal cortex visual association areas, including frontal eye fields. Abbreviations: 8aV, cytoarchitectural area 8a ventral; 23V, cytoarchitectural area 23 ventral; AIP, anterior intraparietal area; DA, dorsoanterior area (probable homolog of macaque area V3a); DI, dorsointermediate area; DM, dorsomedial area (probable homolog of macaque area V6); FST, fundus of superior temporal area; FSTv, fundus of superior temporal ventral area (probable homolog of macaque cytoarchitectural areas PGa and IPa); ITc, caudal inferior temporal area (probable homolog of macaque area TEO); ITd, dorsal inferior temporal area; ITv, ventral inferior temporal area; LIP, lateral intraparietal area; MIP, medial intraparietal area; MST, medial superior temporal area; MT, middle temporal area (probable homolog of macaque area V5); MTC, middle temporal crescent (probable homolog of macaque area V4T); OPt, cytoarchitectural area OPt; PEC, cytoarchitectural area PE caudal; PG, cytoarchitectural area PG; PGM, cytoarchitectural area PG medial; PPM, posterior parietal medial area (probable homolog of macaque area V6a); ProSt, area prostriata; STP, superior temporal polysensory area (probable homolog of macaque cytoarchitectural area TPO); TF/ TL, cytoarchitectural areas TF and TL; V1, primary visual area; V2, second visual area; VIP, ventral intraparietal area; VLA, ventrolateral anterior area (probable homolog of macaque area V4); VLP, ventrolateral posterior area (probable homolog of macaque area V3).
Mentions: Figure 1 illustrates the external morphology of the marmoset brain, with visual and visual association cortical areas highlighted. The marmoset brain (∼8 g) is approximately 12 times smaller in volume than that of the rhesus macaque, and 180 times smaller than the human brain (Stephan et al., 1981). Figure 1 readily conveys one of the key advantages of the marmoset as a model for studies of the visual system: the relatively smooth topology of the cerebral cortex. Thus, in marmosets the vast majority of the visual cortex lies exposed on the surface of the cerebral hemispheres. The only known exceptions are those portions of visual cortex buried in the banks of the calcarine sulcus: that is, the representation of the peripheral visual field in the primary visual cortex (V1; Fritsches and Rosa, 1996), small sectors of the peripheral representation in the second visual area (V2; Rosa et al., 1997), and area prostriata (Yu et al., 2012).

Bottom Line: Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains.Which species is the most appropriate model?Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Psychology, University College London London, UK.

ABSTRACT
Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect to the organization of the cerebral cortex. Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains. Which species is the most appropriate model? Macaque monkeys, the most widely used non-human primates, are not an optimal choice in many practical respects. For example, much of the macaque cerebral cortex is buried within sulci, and is therefore inaccessible to many imaging techniques, and the postnatal development and lifespan of macaques are prohibitively long for many studies of brain maturation, plasticity, and aging. In these and several other respects the marmoset, a small New World monkey, represents a more appropriate choice. Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans. We will argue that the marmoset monkey provides a good subject for studies of a complex visual system, which will likely allow an important bridge linking experiments in animal models to humans.

Show MeSH