Cortical networks for ethologically relevant behaviors in primates

Area of Science:

• Neuroscience
• Evolutionary Biology
• Primate Studies

Background:

• Parietal-frontal networks are crucial for mediating actions in primate brains.
• Consistent organization of these networks is observed across diverse primate lineages, including prosimians and monkeys.

Purpose of the Study:

• To investigate the evolutionary origins and functional organization of parietal-frontal networks in primates.
• To determine if specific functional domains within the posterior parietal cortex (PPC) and frontal motor cortex (FMC) are preferentially interconnected.

Main Methods:

• Electrical microstimulation of PPC and FMC in various primate species to evoke ethologically relevant actions.
• Optical imaging of FMC concurrently with PPC stimulation to map functional connectivity.
• Comparative anatomical analysis of PPC size in primates and related species.

Main Results:

• Electrical stimulation evoked complex movements like reaching and grasping from specific domains in both PPC and FMC.
• PPC domains showed preferential connectivity with matching functional domains in FMC.
• Functional domains within PPC and FMC exhibited consistent organization across different primate branches.

Conclusions:

• Parietal-frontal networks with interconnected functional domains emerged early in primate evolution.
• The posterior parietal cortex (PPC) likely played a limited role in motor behavior before the emergence of archaic primates.
• Functional domains may have evolved in the motor cortex even before the appearance of archaic primates.