Diversity of laminar connections linking periarcuate and lateral intraparietal areas depends on cortical structure

• DOI: 10.1111/j.1460-9568.2005.04522.x
• Publication Date: 2006-01-18T23:36:05Z
• Authors: M. Medalla; H. Barbas
• Keywords: Laminar organization

Abstract Lateral prefrontal and intraparietal cortices have strong connectional functional associations but it is unclear how their common visuomotor, perceptual working memory functions arise. The hierarchical scheme of cortical processing assumes that cortex issues ‘feedback’ projections to parietal cortex. However, the architectonic heterogeneity these raises question whether distinct areas laminar‐specific interconnections underlying complex relationship. Using quantitative procedures, we showed connections between (areas 46 8) lateral (LIPv, LIPd 7a) in Macaca mulatta , studied with neural tracers, varied systematically according rules determined by laminar architecture linked areas. We found axons from rostral 8 terminated heavily layers I–III all areas, as did caudal area LIPv, suggesting communication. contrary previous assumptions, mostly IV–V 7a, ‘feedforward’ These patterns were highly correlated consistent differences neuronal density When a origin was lower than destination, most terminations layer I concomitant decrease IV. opposite occurred when had higher target. findings indicate can reliably predict may form basis understanding complexity prefrontal–intraparietal interactions cognition.