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The organization and evolution of dorsal stream multisensory motor pathways in primates.

Kaas JH, Gharbawie OA, Stepniewska I - Front Neuroanat (2011)

Bottom Line: Each functional zone receives a different pattern of visual and somatosensory inputs, and projects preferentially to functionally matched parts of motor and premotor cortex.As PPC is a relatively small portion of cortex in most mammals, including the close relatives of primates, we suggest that a larger, more significant PPC emerged with the first primates as a region where several ethologically relevant behaviors could be initiated by sensory and intrinsic signals, and mediated via connections with premotor and motor cortex.While several classes of PPC modules appear to be retained by all primates, elaboration and differentiation of these modules likely occurred in some primates, especially humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Vanderbilt University Nashville, TN, USA.

ABSTRACT
In Prosimian primates, New World monkeys, and Old World monkeys microstimulation with half second trains of electrical pulses identifies separate zones in posterior parietal cortex (PPC) where reaching, defensive, grasping, and other complex movements can be evoked. Each functional zone receives a different pattern of visual and somatosensory inputs, and projects preferentially to functionally matched parts of motor and premotor cortex. As PPC is a relatively small portion of cortex in most mammals, including the close relatives of primates, we suggest that a larger, more significant PPC emerged with the first primates as a region where several ethologically relevant behaviors could be initiated by sensory and intrinsic signals, and mediated via connections with premotor and motor cortex. While several classes of PPC modules appear to be retained by all primates, elaboration and differentiation of these modules likely occurred in some primates, especially humans.

No MeSH data available.


Schematic of parietal–frontal connections of the specific movement zones in PPC of galagos. Functionally distinct movement zones (filled with colors) and their connections (indicated by color coordinated lines) are marked on the flattened view of left cerebral hemisphere. Thick lines represent strong connections, and thin lines represent weak connections. Opened sulci are marked with dashed lines.
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Figure 2: Schematic of parietal–frontal connections of the specific movement zones in PPC of galagos. Functionally distinct movement zones (filled with colors) and their connections (indicated by color coordinated lines) are marked on the flattened view of left cerebral hemisphere. Thick lines represent strong connections, and thin lines represent weak connections. Opened sulci are marked with dashed lines.

Mentions: When tracers were injected into specific function zones in rostral PPC, a different pattern of connections was revealed for each zone (Figure 2; see also Stepniewska et al., 2009b). The face aggressive region had strong connections with PMV, while the face defensive region had strong connections with PMD, as well as some direct visual inputs. The hand-to-mouth region had strong connections with cingulate cortex, as well as M1 and PMD, while the defensive zone had some direct visual inputs. The reaching zone had even more direct visual inputs. All zones had connections with somatosensory areas in the S2–PV region, and widespread connections within PPC. The connections of movement-specific PPC zones activate matching zones in M1 and premotor cortex, as revealed by optically imaging patterns of hemodynamic activity in frontal cortex during electrical stimulation of PPC zones (Stepniewska et al., accepted). Moreover, the functioning of the M1 zones is critical to the functioning of the PPC zones, as stimulation of PPC no longer produced movements after the activity of functionally matched parts of M1 was blocked with muscimol (Stepniewska et al., 2008).


The organization and evolution of dorsal stream multisensory motor pathways in primates.

Kaas JH, Gharbawie OA, Stepniewska I - Front Neuroanat (2011)

Schematic of parietal–frontal connections of the specific movement zones in PPC of galagos. Functionally distinct movement zones (filled with colors) and their connections (indicated by color coordinated lines) are marked on the flattened view of left cerebral hemisphere. Thick lines represent strong connections, and thin lines represent weak connections. Opened sulci are marked with dashed lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3116136&req=5

Figure 2: Schematic of parietal–frontal connections of the specific movement zones in PPC of galagos. Functionally distinct movement zones (filled with colors) and their connections (indicated by color coordinated lines) are marked on the flattened view of left cerebral hemisphere. Thick lines represent strong connections, and thin lines represent weak connections. Opened sulci are marked with dashed lines.
Mentions: When tracers were injected into specific function zones in rostral PPC, a different pattern of connections was revealed for each zone (Figure 2; see also Stepniewska et al., 2009b). The face aggressive region had strong connections with PMV, while the face defensive region had strong connections with PMD, as well as some direct visual inputs. The hand-to-mouth region had strong connections with cingulate cortex, as well as M1 and PMD, while the defensive zone had some direct visual inputs. The reaching zone had even more direct visual inputs. All zones had connections with somatosensory areas in the S2–PV region, and widespread connections within PPC. The connections of movement-specific PPC zones activate matching zones in M1 and premotor cortex, as revealed by optically imaging patterns of hemodynamic activity in frontal cortex during electrical stimulation of PPC zones (Stepniewska et al., accepted). Moreover, the functioning of the M1 zones is critical to the functioning of the PPC zones, as stimulation of PPC no longer produced movements after the activity of functionally matched parts of M1 was blocked with muscimol (Stepniewska et al., 2008).

Bottom Line: Each functional zone receives a different pattern of visual and somatosensory inputs, and projects preferentially to functionally matched parts of motor and premotor cortex.As PPC is a relatively small portion of cortex in most mammals, including the close relatives of primates, we suggest that a larger, more significant PPC emerged with the first primates as a region where several ethologically relevant behaviors could be initiated by sensory and intrinsic signals, and mediated via connections with premotor and motor cortex.While several classes of PPC modules appear to be retained by all primates, elaboration and differentiation of these modules likely occurred in some primates, especially humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Vanderbilt University Nashville, TN, USA.

ABSTRACT
In Prosimian primates, New World monkeys, and Old World monkeys microstimulation with half second trains of electrical pulses identifies separate zones in posterior parietal cortex (PPC) where reaching, defensive, grasping, and other complex movements can be evoked. Each functional zone receives a different pattern of visual and somatosensory inputs, and projects preferentially to functionally matched parts of motor and premotor cortex. As PPC is a relatively small portion of cortex in most mammals, including the close relatives of primates, we suggest that a larger, more significant PPC emerged with the first primates as a region where several ethologically relevant behaviors could be initiated by sensory and intrinsic signals, and mediated via connections with premotor and motor cortex. While several classes of PPC modules appear to be retained by all primates, elaboration and differentiation of these modules likely occurred in some primates, especially humans.

No MeSH data available.