scholarly journals Divergent Connectional Asymmetries of the Inferior Parietal Lobule Shape Hemispheric Specialization in Humans, Chimpanzees, and Macaque Monkeys

2021 ◽  
Author(s):  
Luqi Cheng ◽  
Yuanchao Zhang ◽  
Gang Li ◽  
Jiaojian Wang ◽  
William D. Hopkins ◽  
...  

AbstractThe inferior parietal lobule (IPL) is one of the most expanded and structurally and functionally asymmetric regions in the human cerebral cortex. Whether the structural and connectional asymmetries of IPL subdivisions differ across primate species and whether this relates to functional asymmetries remain unclear. We identified IPL subregions that exhibited symmetric positive allometric scaling across macaque monkeys, chimpanzees, and humans. Patterns of IPL subregions asymmetry were similar in chimpanzees and humans, whereas no IPL asymmetries were evident in macaques. Among the comparative sample of primates, humans showed the most widespread asymmetric connections in the frontal, parietal, and temporal cortices, constituting leftward asymmetric networks that may provide an anatomical basis for language and tool use. Unique human asymmetric connectivity between the IPL and the primary motor cortex may be related to handedness. These findings suggest that structural and connectional asymmetries may underlie hemispheric specialization of the human brain.

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Luqi Cheng ◽  
Yuanchao Zhang ◽  
Gang Li ◽  
Jiaojian Wang ◽  
Chet Sherwood ◽  
...  

The inferior parietal lobule (IPL) is one of the most expanded cortical regions in humans relative to other primates. It is also among the most structurally and functionally asymmetric regions in the human cerebral cortex. Whether the structural and connectional asymmetries of IPL subdivisions differ across primate species and how this relates to functional asymmetries remain unclear. We identified IPL subregions that exhibited positive allometric in both hemispheres, scaling across rhesus macaque monkeys, chimpanzees, and humans. The patterns of IPL subregions asymmetry were similar in chimpanzees and humans, but no IPL asymmetries were evident in macaques. Among the comparative sample of primates, humans showed the most widespread asymmetric connections in the frontal, parietal, and temporal cortices, constituting leftward asymmetric networks that may provide an anatomical basis for language and tool use. Unique human asymmetric connectivity between the IPL and primary motor cortex might be related to handedness. These findings suggest that structural and connectional asymmetries may underlie hemispheric specialization of the human brain.


2020 ◽  
Vol 54 (6) ◽  
pp. 136-143
Author(s):  
I.V. Saenko ◽  
◽  
L.A. Chernikova ◽  
A.E. Khizhnikova ◽  
E.I. Kremneva ◽  
...  

The paper discusses the findings of studying neuroplastic transformations in the brain cortex owing to stroke patients therapy using soft multimodel exoskeleton complex (MEC) REGENT in comparison with activation of the cortex structures controlling locomotion in healthy people. The MEC course applied to hemiparetic patients increases walk speed; changes in the activity zones detected by functional magnetic resonance imaging (fMRI) attest to the positive trajectory of neuroplastic processes, i.e. activation in the precentral gyrus (primary motor cortex), secondary association cortex (inferior parietal lobule) on the damaged hemisphere, and right-side primary sensorimotor cortex. Analysis of the functional connectivity between the areas of interest before and after the MEC therapy elicited significant changes in the inter- and intra-hemispheric connections. This positive cortical reorganization has its origin in reduction of excitory interactions between the secondary associative areas (inferior parietal lobules in both hemispheres) and alleviation of the inhibitory interaction between the inferior parietal lobule and primary right-side sensorimotor cortex in the damaged hemisphere.


NeuroImage ◽  
2021 ◽  
Vol 231 ◽  
pp. 117843 ◽  
Author(s):  
Meiqi Niu ◽  
Lucija Rapan ◽  
Thomas Funck ◽  
Seán Froudist-Walsh ◽  
Ling Zhao ◽  
...  

2017 ◽  
Vol 41 (S1) ◽  
pp. S409-S409
Author(s):  
A. Gadad ◽  
D.Y.C.J. Reddy ◽  
D.G. Venkatasubramanian ◽  
D.J. C.N

Aim of the studyTo study the neural substrates of insight in OCD by comparing patients with good insight, patients with poor insight and matched healthy controls using functional MRI.MethodologySubjects were recruited from among patients attending OCD clinic, adult psychiatry services and psychiatry ward inpatients of National Institute of Mental Health And Neurosciences (NIMHANS), Bangalore. They were further divided into ‘good insight’ (n = 30) and ‘poor insight’ (n = 14) using Brown's assessment of belief's scale. Control subjects (n = 30) were recruited from consenting volunteers. 3 T MRI was used mental rotation task was paradigm used for fMRI and analysis was done by SPM 8.ResultsPoor insight patients and good insight patients comparison revealed differential activation in left superior/medial frontal gyrus (corresponding to the DLPFC). A negative correlation between BABS score and activation of right inferior parietal lobule. Mental rotation task behavioural data results: OCD patients as a group had significantly lower accuracy compared to healthy controls. Poor insight group had significantly decreased accuracy ratio compared to good insight group and healthy controls. A negative correlation was noted between BABS score and accuracy ratio, indicating that poorer the insight, greater the errors during the active task.ConclusionInsight has been important prognostic factor in OCD. Poor insight patients had specific deficits in left medial frontal gyrus and right inferior parietal lobule as compared to good insight patients and healthy controls. Together, these indicate that insight has a strong neurobiological underpinning in OCD.Disclosure of interestThe authors have not supplied their declaration of competing interest.


2017 ◽  
Vol 28 (6) ◽  
pp. 2162-2174 ◽  
Author(s):  
Quanjing Chen ◽  
Frank E Garcea ◽  
Robert A Jacobs ◽  
Bradford Z Mahon

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