Cortical Connections of the Inferior Parietal Cortical Convexity of the Macaque Monkey

Abstract

We traced the cortical connections of the 4 cytoarchitectonic fields--Opt, PG, PFG, PF--forming the cortical convexity of the macaque inferior parietal lobule (IPL). Each of these fields displayed markedly distinct sets of connections. Although Opt and PG are both targets of dorsal visual stream and temporal visual areas, PG is also target of somatosensory and auditory areas. Primary parietal and frontal connections of Opt include area PGm and eye-related areas. In contrast, major parietal and frontal connections of PG include IPL, caudal superior parietal lobule (SPL), and agranular frontal arm-related areas. PFG is target of somatosensory areas and also of the medial superior temporal area (MST) and temporal visual areas and is connected with IPL, rostral SPL, and ventral premotor arm- and face-related areas. Finally, PF is primarily connected with somatosensory areas and with parietal and frontal face- and arm-related areas. The present data challenge the bipartite subdivision of the IPL convexity into a caudal and a rostral area (7a and 7b, respectively) and provide a new anatomical frame of reference of the macaque IPL convexity that advances our present knowledge on the functional organization of this cortical sector, giving new insight into its possible role in space perception and motor control.

Primary somatosensory cortex discriminates affective significance in social touch

“…In contrast, BA2 is more of a tactile association area. It receives somatosensory input from BA3 but has reciprocal connections with cortical regions that combine visual, auditory, and somatosensory information (47)(48)(49)(50)(51) and respond to complex visual stimuli: the fundus of the intraparietal sulcus (ventral intraparietal area) responding to the sight of touch (52), the inferior parietal lobule (areas PF/PFG in particular) and the premotor cortex responding to the sight of actions (48,51), and finally the ACC and insula responding to the sight of emotions (47,53). Electrophysiologically controlled tracer injections in the limb representation of BA2 have not revealed direct connections with the OFC (50), making OFC an unlikely source of direct information to BA2 [but weak direct connections may exist between the tongue representation of SI and the OFC for integration of texture and taste (54,55)].…”

“…Our PPI analysis further constrains these routes by showing that, of the regions showing increased activation during the visually female compared with the visually male caress condition, only two, the visual cortex and the posterior parietal lobe, displayed the augmented functional connectivity that would be expected from a region that modulates SI across the sex conditions. As BA2 has anatomical connections with the posterior parietal lobe but not the visual cortex (47)(48)(49)(50)(51)56), the posteriorparietal lobe is the most likely source of visual information to SI.…”

Early Binding of Gaze, Gesture, and Emotion: Neural Time Course and Correlates

“…This region is likely equivalent to the macaque area F5c (Rizzolatti et al, 2001). It is strongly connected to the SMA, primary motor area M1, PFop, and SII (Luppino et al, 1993;Rozzi et al, 2006;Gerbella et al, 2011) and hosts visuomotor representations (Rizzolatti et al, 2001).…”

The functional role of the parieto-frontal mirror circuit: interpretations and misinterpretations

“…both these areas are heavily connected with F5: pFG mostly with F5c, and the AIp with F5a 14 . both area pFG and the AIp receive higher-order visual information from the cortex located inside the superior temporal sulcus (STS) [13][14] . STS areas, like mirror areas, encode biological motion, but they lack motor properties.…”