A comprehensive analysis of variability in the sulci that define the inferior frontal gyrus in the chimpanzee ( <scp> <i>Pan troglodytes</i> </scp> ) brain

International audienceObjectives: In the human brain, the inferior frontal gyrus (IFG) is comprised of three morphological regions, which include the pars opercularis, pars triangularis, and pars orbitalis. These brains regions are implicated in a number of cognitive and linguistic functions, and the pars opercularis and pars triangularis of the language dominant hemisphere are collectively referred to as Broca's area. Evolution of the morphology of the IFG has been a topic of study in comparative neuroscience. Materials and Methods: Using magnetic resonance images (MRI) from 294 chimpanzees with known pedigrees, we quantified the folding patterns, surface area, and depth of three sulci and their subdivisions that define the IFG. Results: Chimpanzees show considerable individual variation in IFG sulci. A higher proportion of males and chimpanzees with better orofacial motor control had a bifurcation in the dorsal limb of the fronto-orbital sulcus. For surface area and depth, chimpanzees with better orofacial motor control had greater leftward asymmetries in surface area and increased gyrification for the fronto-orbital sulcus and greater rightward biases for the inferior precentral sulcus. Quantitative genetic analyses revealed that the average surface area and depth for three of the five sulci subdivisions were significantly heritable. By contrast, we found no evidence for heritability in asymmetries for any of the sulci

Sulcal Morphology in Cingulate Cortex is Associated with Voluntary Oro-Facial Motor Control and Gestural Communication in Chimpanzees (Pan troglodytes)

International audienceAbstract Individual differences in sulcal variation within the anterior and mid-cingulate cortex of the human brain, particularly the presence or absence of a paracingulate sulcus (PCGS), are associated with various motor and cognitive processes. Recently, it has been reported that chimpanzees possess a PCGS, previously thought to be a unique feature of the human brain. Here, we examined whether individual variation in the presence or absence of a PCGS as well as the variability in the intralimbic sulcus (ILS) are associated with oro-facial motor control, handedness for manual gestures, and sex in a sample of MRI scans obtained in 225 chimpanzees. Additionally, we quantified the depth of the cingulate sulcus (CGS) along the anterior–posterior axis and tested for association with oro-facial motor control, handedness, and sex. Chimpanzees with better oro-facial motor control were more likely to have a PCGS, particularly in the left hemisphere compared to those with poorer control. Male chimpanzees with better oro-facial motor control showed increased leftward asymmetries in the depth of the anterior CGS, whereas female chimpanzees showed the opposite pattern. Significantly, more chimpanzees had an ILS in the left compared to the right hemisphere, but variability in this fold was not associated with sex, handedness, or oro-facial motor control. Finally, significant population-level leftward asymmetries were found in the anterior portion of the CGS, whereas significant rightward biases were evident in the posterior regions. The collective results suggest that the emergence of a PCGS and enhanced gyrification within the anterior and mid-cingulate gyrus may have directly or indirectly evolved in response to selection for increasing oro-facial motor control in primates

Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging

Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently developed a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience

Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging

Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently devel-oped a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience