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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.


Dorsolateral view of a squirrel monkey brain. The reach, defense, and grasp zones identified with long-train electrical stimulation are arranged in PPC in a caudomedial to rostrolateral pattern. PPCr, rostral PPC and PPCc, caudal PPC. All other conventions are the same as in Figure 1.
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Figure 3: Dorsolateral view of a squirrel monkey brain. The reach, defense, and grasp zones identified with long-train electrical stimulation are arranged in PPC in a caudomedial to rostrolateral pattern. PPCr, rostral PPC and PPCc, caudal PPC. All other conventions are the same as in Figure 1.

Mentions: Using the same stimulation and anatomical procedures, functional zones in PPC, and in motor, and premotor cortex, were revealed in New World owl and squirrel monkeys (Gharbawie et al., 2010, 2011). These studies focused on defining reach, defense, and grasp zones, which were found in both PPC and frontal cortex. As in galagos, these three PPC zones were arranged in a mediolateral sequence with a rostrolateral slant in owl and squirrel monkeys (Figure 3). Area 1 has been well defined in owl and squirrel monkeys on the basis of a characteristic representation of the cutaneous receptors of the contralateral body (Merzenich et al., 1978; Sur et al., 1982). We consider a narrow strip of cortex along the caudal border of area 1 to be area 2, as in macaque monkeys, although the evidence for this cortex being area 2 is limited. This cortex has also been considered to be part of PPC (Padberg et al., 2005). In either case, the grasp zone in owl and squirrel monkeys was centered in cortex identified here as area 2. In addition, the PPC defense region extends into area 2 and even somewhat into area 1. Some of this spread may be due to local spread across areal boundaries of electrical stimulation, but the evidence suggests that parts of area 2 are within the PPC motor movement system. A reach zone was consistently caudal to area 2 and was likely in area 5. In frontal cortex reaching movements were evoked from part of PMD and an adjoining part of M1, defense movements from lateral M1 and part of PMV, and grasping movements from part of the forelimb representation in M1 and PMV. Thus, corresponding movement zones can be identified in PPC, M1, and premotor cortex.


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

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

Dorsolateral view of a squirrel monkey brain. The reach, defense, and grasp zones identified with long-train electrical stimulation are arranged in PPC in a caudomedial to rostrolateral pattern. PPCr, rostral PPC and PPCc, caudal PPC. All other conventions are the same as in Figure 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Dorsolateral view of a squirrel monkey brain. The reach, defense, and grasp zones identified with long-train electrical stimulation are arranged in PPC in a caudomedial to rostrolateral pattern. PPCr, rostral PPC and PPCc, caudal PPC. All other conventions are the same as in Figure 1.
Mentions: Using the same stimulation and anatomical procedures, functional zones in PPC, and in motor, and premotor cortex, were revealed in New World owl and squirrel monkeys (Gharbawie et al., 2010, 2011). These studies focused on defining reach, defense, and grasp zones, which were found in both PPC and frontal cortex. As in galagos, these three PPC zones were arranged in a mediolateral sequence with a rostrolateral slant in owl and squirrel monkeys (Figure 3). Area 1 has been well defined in owl and squirrel monkeys on the basis of a characteristic representation of the cutaneous receptors of the contralateral body (Merzenich et al., 1978; Sur et al., 1982). We consider a narrow strip of cortex along the caudal border of area 1 to be area 2, as in macaque monkeys, although the evidence for this cortex being area 2 is limited. This cortex has also been considered to be part of PPC (Padberg et al., 2005). In either case, the grasp zone in owl and squirrel monkeys was centered in cortex identified here as area 2. In addition, the PPC defense region extends into area 2 and even somewhat into area 1. Some of this spread may be due to local spread across areal boundaries of electrical stimulation, but the evidence suggests that parts of area 2 are within the PPC motor movement system. A reach zone was consistently caudal to area 2 and was likely in area 5. In frontal cortex reaching movements were evoked from part of PMD and an adjoining part of M1, defense movements from lateral M1 and part of PMV, and grasping movements from part of the forelimb representation in M1 and PMV. Thus, corresponding movement zones can be identified in PPC, M1, and premotor cortex.

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.