scholarly journals Connectional asymmetry of the inferior parietal lobule shapes hemispheric specialization in humans, chimpanzees, and rhesus macaques

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Luqi Cheng ◽  
Yuanchao Zhang ◽  
Gang Li ◽  
Jiaojian Wang ◽  
Chet Sherwood ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Rhesus Macaques ◽  
Hemispheric Specialization ◽  
Primate Species ◽  
Inferior Parietal Lobule ◽  
Human Cerebral Cortex ◽  
Anatomical Basis ◽  
Asymmetric Networks ◽  
Parietal Lobule ◽  
Cortical Regions

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.

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 ◽  
...  
Keyword(s):  
Primary Motor Cortex ◽  
Allometric Scaling ◽  
Hemispheric Specialization ◽  
Primate Species ◽  
Inferior Parietal Lobule ◽  
Human Cerebral Cortex ◽  
Macaque Monkeys ◽  
Anatomical Basis ◽  
Asymmetric Networks ◽  
Parietal Lobule

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.

Association of dorsal inferior frontooccipital fasciculus fibers in the deep parietal lobe with both reading and writing processes: a brain mapping study

2014 ◽  
Vol 121 (1) ◽  
pp. 142-148 ◽  
Author(s):  
Kazuya Motomura ◽  
Masazumi Fujii ◽  
Satoshi Maesawa ◽  
Shunichiro Kuramitsu ◽  
Atsushi Natsume ◽  
...  
Keyword(s):  
White Matter ◽  
Parietal Lobe ◽  
Diffusion Tensor ◽  
Inferior Parietal Lobule ◽  
White Matter Tracts ◽  
Reading And Writing ◽  
Writing Processes ◽  
Subcortical Stimulation ◽  
Parietal Lobule ◽  
Cortical Regions

Alexia and agraphia are disorders common to the left inferior parietal lobule, including the angular and supramarginal gyri. However, it is still unclear how these cortical regions interact with other cortical sites and what the most important white matter tracts are in relation to reading and writing processes. Here, the authors present the case of a patient who underwent an awake craniotomy for a left inferior parietal lobule glioma using direct cortical and subcortical electrostimulation. The use of subcortical stimulation allowed identification of the specific white matter tracts associated with reading and writing. These tracts were found as portions of the dorsal inferior frontooccipital fasciculus (IFOF) fibers in the deep parietal lobe that are responsible for connecting the frontal lobe to the superior parietal lobule. These findings are consistent with previous diffusion tensor imaging tractography and functional MRI studies, which suggest that the IFOF may play a role in the reading and writing processes. This is the first report of transient alexia and agraphia elicited through intraoperative direct subcortical electrostimulation, and the findings support the crucial role of the IFOF in reading and writing.

DYNAMICS OF THE PROCESSES OF INTER- AND INTRA-HEMISPHERIC INTERACTIONS (FUNCTIONAL CONNECTIVITY) OF THE BRAIN MOTOR ZONES RESPONSIBLE FOR WALKING IN NEURO-REHABILITATION OF PATIENTS WITH FOCAL DAMAGES OF THE CENTRAL NERVOUS SYSTEM

2020 ◽  
Vol 54 (6) ◽  
pp. 136-143
Author(s):  
I.V. Saenko ◽  
◽  
L.A. Chernikova ◽  
A.E. Khizhnikova ◽  
E.I. Kremneva ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Sensorimotor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Reorganization ◽  
Association Cortex ◽  
Precentral Gyrus ◽  
Inferior Parietal Lobule ◽  
Inhibitory Interaction ◽  
Parietal Lobule ◽  
The Brain

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.

scholarly journals Hemispheric Specialization of the Primate Inferior Parietal Lobule

2021 ◽  
Author(s):  
Sam Vickery ◽  
Simon B Eickhoff ◽  
Patrick Friedrich
Keyword(s):  
Hemispheric Specialization ◽  
Inferior Parietal Lobule ◽  
Parietal Lobule

Human cortical regions activated by wide-field visual motion: an H2(15)O PET study

1995 ◽  
Vol 74 (1) ◽  
pp. 413-427 ◽  
Author(s):  
K. Cheng ◽  
H. Fujita ◽  
I. Kanno ◽  
S. Miura ◽  
K. Tanaka
Keyword(s):  
Visual Motion ◽  
Magnetic Resonance Images ◽  
Brodmann Area ◽  
Wide Field ◽  
Inferior Parietal Lobule ◽  
Superior Parietal Lobule ◽  
Temporal Area ◽  
Middle Temporal ◽  
Parietal Lobule ◽  
Cortical Regions

1. Several areas in the monkey dorsal visual pathway, including the dorsal part of the medial superior temporal area, have been found to contain cells responding to movements of a wide visual field and are suggested to be involved in analyzing self-induced motion information. In the present study, positron emission tomography was used to localize human cortical regions responding to wide-field visual motion. Changes in regional cerebral blood flow (rCBF) were measured when subjects maintained fixation and viewed low-contrast (0.15 log units brighter than the background) dots subtending 80 x 80 degrees and moving either coherently or incoherently. Brain foci were localized after activity in a fixation-only paradigm was subtracted from that in the two moving dot paradigms. 2. Both the coherent and incoherent movements significantly activated the primary/secondary visual cortex and surrounding visual areas in the cuneus and superior occipital gyrus. Subtraction of images between the coherent and incoherent movements showed that the activity caused by the two types of movement was comparable in these early visual cortical regions. 3. In the lateral occipitotemporoparietal cortex, the coherent movement specifically activated two separate areas; a posterior focus was located at the border of the right occipitotemporal gyri, and a dorsoanterior focus was located bilaterally in the temporoparietal cortex. The incoherent movement did not activate these regions. 4. A fine anatomic localization using individual magnetic resonance images was performed for the bilateral activation in the temporoparietal cortex, which was found to be located mainly in the depth of the inferior parietal lobule and a small portion of the superior and middle temporal gyri. 5. Both the coherent and incoherent movements activated a part of the superior parietal lobule located within the intraparietal sulcus (Brodmann area 7). The bilateral foci activated by the coherent movement were located more anteriorly than the focus activated by the incoherent movement. Subtraction images between the coherent and incoherent movements, however, did not reveal any significant rCBF increases in the superior parietal lobule. 6. Several other cortical regions known to be involved in visuospatial and visuomotor functions were also activated by the coherent movement, including the frontal eye field (Brodmann area 8) and premotor cortex (Brodmann area 6) in the frontal lobe. 7. The posteriorly located activation at the border of occipito-temporal gyri corresponds to the homologue of the middle temporal area reported in previous activation studies using small to medium-sized motion stimuli. The bilateral activation in the inferior parietal lobule appeared to rely on wide-field motion stimulation.

scholarly journals Organization of the macaque monkey inferior parietal lobule based on multimodal receptor architectonics

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

Neuroimaging correlates of insight in obsessive compulsive disorder: A fMRI study

2017 ◽  
Vol 41 (S1) ◽  
pp. S409-S409
Author(s):  
A. Gadad ◽  
D.Y.C.J. Reddy ◽  
D.G. Venkatasubramanian ◽  
D.J. C.N
Keyword(s):  
Mental Rotation ◽  
Negative Correlation ◽  
Mental Rotation Task ◽  
Healthy Controls ◽  
Inferior Parietal Lobule ◽  
Good Insight ◽  
Compulsive Disorder ◽  
Accuracy Ratio ◽  
Parietal Lobule ◽  
Medial Frontal Gyrus

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.

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