The Connectivity–Based Parcellation of The Angular Gyrus: Fiber Dissection And MR Tractography Study

Abstract The angular gyrus (AG) wraps the posterior end of the superior temporal sulcus (STS), so it is considered as a continuation of the superior/middle temporal gyrus and forms the inferior parietal lobule (IPL) with the supramarginal gyrus (SMG). The AG was functionally divided in the literature, but there is no fiber dissection study in this context. This study divided AG into superior (sAG) and inferior (iAG) parts by focusing on STS. Red blue silicone injected eight human cadaveric cerebrums were dissected via the Klingler method focusing on the AG. White matter (WM) tracts identified during dissection were then reconstructed on the Human Connectome Project 1065 individual template for validation. According to this study, superior longitudinal fasciculus (SLF) II and middle longitudinal fasciculus (MdLF) are associated with sAG; the anterior commissure (AC), optic radiation (OR) with iAG; the arcuate fasciculus (AF), inferior frontooccipital fasciculus (IFOF), and tapetum (Tp) with both parts. In cortical parcellation of AG based on STS, sAG and iAG were found to be associated with different fiber tracts. Although it has been shown in previous studies that there are functionally different subunits with AG parcellation, here, for the first time, different functions of the subunits have been revealed with cadaveric dissection and tractography images.

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Microsurgical and Tractographic Anatomical Study of Transtemporal-Transchoroidal Fissure Approaches to the Ambient Cistern

Operative Neurosurgery ◽

10.1093/ons/opaa272 ◽

2020 ◽

Cited By ~ 1

Author(s):

Emrah Egemen ◽

Pinar Celtikci ◽

Yücel Dogruel ◽

Fatih Yakar ◽

Defne Sahinoglu ◽

...

Keyword(s):

White Matter ◽

Anterior Commissure ◽

Temporal Cortex ◽

Anatomical Study ◽

Middle Temporal Gyrus ◽

Detailed Knowledge ◽

Fiber Tractography ◽

Human Connectome Project ◽

Fiber Dissection ◽

Ambient Cistern

Abstract BACKGROUND Approaching ambient cistern lesions is still a challenge because of deep location and related white matter tracts (WMTs) and neural structures. OBJECTIVE To investigate the white matter anatomy in the course of 3 types of transtemporal-transchoroidal fissure approaches (TTcFA) to ambient cistern by using fiber dissection technique with translumination and magnetic resonance imaging fiber tractography. METHODS Eight formalin-fixed cerebral hemispheres were dissected on surgical corridor from the temporal cortex to the ambient cistern by using Klingler's method. The trans-middle temporal gyrus, trans-inferior temporal sulcus (TITS), and trans-inferior temporal gyrus (TITG) approaches were evaluated. WMTs that were identified during dissection were then reconstructed on the Human Connectome Project 1021 individual template for validation. RESULTS The trans-middle gyrus approach interrupted the U fibers, arcuate fasciculus (AF), the ventral segment of inferior frontoocipital fasciculus (IFOF), the temporal extensions of the anterior commissure (AC) posterior crura, the tapetum (Tp) fibers, and the anterior loop of the optic radiation (OR). The TITS approach interrupted U fibers, inferior longitudinal fasciculus (ILF), IFOF, and OR. The TITG approach interrupted the U fibers, ILF, and OR. The middle longitudinal fasciculus, ILF, and uncinate fasciculus (UF) were not interrupted in the trans-middle gyrus approach and the AF, UF, AC, and Tp fibers were not interrupted in the TITS/gyrus approaches. CONCLUSION Surgical planning of the ambient cistern lesions requires detailed knowledge about WMTs. Fiber dissection and tractography techniques improve the orientation during surgery and may help decrease surgical complications.

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Spatiotemporal Human Brain Activities on Recalling Names of Body Parts

Journal of Advanced Computational Intelligence and Intelligent Informatics ◽

10.20965/jaciii.2013.p0386 ◽

2013 ◽

Vol 17 (3) ◽

pp. 386-391 ◽

Cited By ~ 3

Author(s):

Takahiro Yamanoi ◽

◽

Yoshinori Tanaka ◽

Mika Otsuki ◽

Shin-ichi Ohnishi ◽

...

Keyword(s):

Right Hemisphere ◽

Event Related Potentials ◽

Angular Gyrus ◽

Middle Temporal Gyrus ◽

Dipole Source ◽

Body Parts ◽

Current Dipole ◽

Middle Temporal ◽

Related Potentials ◽

The Right

The authors measure electroencephalograms (EEGs) from a subject looking at line drawings of body parts and recalling their names silently. The equivalent current dipole source localization (ECDL) method is applied to the event related potentials (ERPs): summed EEGs. As the dominant language area of the subject is considered to be in the right hemisphere in the previous research study, ECDs are localized to the right middle temporal gyrus: the angular gyrus. Then ECDs are localized to the right fusiform gyrus, the right middle temporal pole (TEP), and the right inferior temporal white matter (TWM). ECDs are located in the ventral pathway. The areas are related to the integrated process of visual recognition of pictures and the recalling of words. Some of these areas are also related to image recognition and word generation.

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Exploring the Neural Correlates of Social Stereotyping

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2009.21091 ◽

2009 ◽

Vol 21 (8) ◽

pp. 1560-1570 ◽

Cited By ~ 48

Author(s):

Susanne Quadflieg ◽

David J. Turk ◽

Gordon D. Waiter ◽

Jason P. Mitchell ◽

Adrianna C. Jenkins ◽

...

Keyword(s):

Gender Stereotypes ◽

Neural Activity ◽

Neural Correlates ◽

Middle Temporal Gyrus ◽

Supramarginal Gyrus ◽

Cultural Stereotypes ◽

Middle Temporal ◽

Ventral Medial Prefrontal Cortex ◽

Action Knowledge ◽

The Brain

Judging people on the basis of cultural stereotypes is a ubiquitous facet of daily life, yet little is known about how this fundamental inferential strategy is implemented in the brain. Using fMRI, we measured neural activity while participants made judgments about the likely actor (i.e., person-focus) and location (i.e., place-focus) of a series of activities, some of which were associated with prevailing gender stereotypes. Results revealed that stereotyping was underpinned by activity in areas associated with evaluative processing (e.g., ventral medial prefrontal cortex, amygdala) and the representation of action knowledge (e.g., supramarginal gyrus, middle temporal gyrus). In addition, activity accompanying stereotypic judgments was correlated with the strength of participants' explicit and implicit gender stereotypes. These findings elucidate how stereotyping fits within the neuroscience of person understanding.

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Automatic and Controlled Semantic Retrieval: TMS Reveals Distinct Contributions of Posterior Middle Temporal Gyrus and Angular Gyrus

Journal of Neuroscience ◽

10.1523/jneurosci.4705-14.2015 ◽

2015 ◽

Vol 35 (46) ◽

pp. 15230-15239 ◽

Cited By ~ 83

Author(s):

J. Davey ◽

P. L. Cornelissen ◽

H. E. Thompson ◽

S. Sonkusare ◽

G. Hallam ◽

...

Keyword(s):

Angular Gyrus ◽

Middle Temporal Gyrus ◽

Semantic Retrieval ◽

Middle Temporal

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Brain Damage Associated with Impaired Sentence Processing in Acute Aphasia

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01478 ◽

2020 ◽

Vol 32 (2) ◽

pp. 256-271 ◽

Cited By ~ 4

Author(s):

Sigfus Kristinsson ◽

Helga Thors ◽

Grigori Yourganov ◽

Sigridur Magnusdottir ◽

Haukur Hjaltason ◽

...

Keyword(s):

Brain Damage ◽

Sentence Processing ◽

Syntactic Processing ◽

Angular Gyrus ◽

Matching Task ◽

Middle Temporal Gyrus ◽

Broca’S Area ◽

Broca's Area ◽

Middle Temporal ◽

Acute Aphasia

Left-hemisphere brain damage commonly affects patients' abilities to produce and comprehend syntactic structures, a condition typically referred to as “agrammatism.” The neural correlates of agrammatism remain disputed in the literature, and distributed areas have been implicated as important predictors of performance, for example, Broca's area, anterior temporal areas, and temporo-parietal areas. We examined the association between damage to specific language-related ROIs and impaired syntactic processing in acute aphasia. We hypothesized that damage to the posterior middle temporal gyrus, and not Broca's area, would predict syntactic processing abilities. One hundred four individuals with acute aphasia (<20 days poststroke) were included in the study. Structural MRI scans were obtained, and all participants completed a 45-item sentence–picture matching task. We performed an ROI-based stepwise regression analyses to examine the relation between cortical brain damage and impaired comprehension of canonical and noncanonical sentences. Damage to the posterior middle temporal gyrus was the strongest predictor for overall task performance and performance on noncanonical sentences. Damage to the angular gyrus was the strongest predictor for performance on canonical sentences, and damage to the posterior superior temporal gyrus predicted noncanonical scores when performance on canonical sentences was included as a cofactor. Overall, our models showed that damage to temporo-parietal and posterior temporal areas was associated with impaired syntactic comprehension. Our results indicate that the temporo-parietal area is crucially implicated in complex syntactic processing, whereas the role of Broca's area may be complementary.

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III. A comparison of the latency periods of the ocular muscles on excitation of the frontal and occipito-temporal regions of the brain

Proceedings of the Royal Society of London ◽

10.1098/rspl.1887.0158 ◽

1888 ◽

Vol 43 (258-265) ◽

pp. 411-412 ◽

Cited By ~ 4

Keyword(s):

Cerebral Cortex ◽

Occipital Lobe ◽

Superior Temporal Gyrus ◽

Frontal Region ◽

Angular Gyrus ◽

Middle Temporal Gyrus ◽

Middle Temporal ◽

Posterior Limb ◽

The Brain

Conjugate deviation of the eyes to the opposite side is produced by excitation of entirely different regions of the cerebral cortex. The parts which when electrically excited produce this movement are: (1) An area in the frontal region of the hemisphere which is included in the motor or psychomotor zone of authors; (2) the superior temporal gyrus; (3) the upper end of the middle temporal gyrus; (4) the posterior limb of the angular gyrus; (5) the whole cortex of the occipital lobe including its mesial and under surfaces; (6) the quadrate lobule.

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Indirect White Matter Pathways Are Associated With Treated Naming Improvement in Aphasia

Neurorehabilitation and Neural Repair ◽

10.1177/1545968321999052 ◽

2021 ◽

pp. 154596832199905

Author(s):

Janina Wilmskoetter ◽

Julius Fridriksson ◽

Alexandra Basilakos ◽

Lorelei Phillip Johnson ◽

Barbara Marebwa ◽

...

Keyword(s):

White Matter ◽

Treatment Outcomes ◽

Inferior Frontal Gyrus ◽

Brain Regions ◽

Angular Gyrus ◽

Middle Temporal Gyrus ◽

Middle Temporal ◽

Pars Opercularis ◽

Left Hemisphere Stroke ◽

Linear Regressions

Background White matter disconnection of language-specific brain regions associates with worse aphasia recovery. Despite a loss of direct connections, many stroke survivors may maintain indirect connections between brain regions. Objective To determine (1) whether preserved direct connections between language-specific brain regions relate to better poststroke naming treatment outcomes compared to no direct connections and (2) whether for individuals with a loss of direct connections, preserved indirect connections are associated with better treatment outcomes compared to individuals with no connections. Methods We computed structural whole-brain connectomes from 69 individuals with chronic left-hemisphere stroke and aphasia who completed a 3-week-long language treatment that was supplemented by either anodal transcranial direct current stimulation (A-tDCS) or sham stimulation (S-tDCS). We determined differences in naming improvement between individuals with direct, indirect, and no connections using 1-way analyses of covariance and multivariable linear regressions. Results Independently of tDCS modality, direct or indirect connections between the inferior frontal gyrus pars opercularis and angular gyrus were both associated with a greater increase in correct naming compared to no connections ( P = .027 and P = .039, respectively). Participants with direct connections between the inferior frontal gyrus pars opercularis and middle temporal gyrus who received S-tDCS and participants with indirect connections who received A-tDCS significantly improved in naming accuracy. Conclusions Poststroke preservation of indirect white matter connections is associated with better treated naming improvement in aphasia even when direct connections are damaged. This mechanistic information can be used to stratify and predict treated naming recovery in individuals with aphasia.

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Surgical Approaches to the Temporal Horn: An Anatomic Analysis of White Matter Tract Interruption

Operative Neurosurgery ◽

10.1093/ons/opw011 ◽

2016 ◽

Vol 13 (2) ◽

pp. 258-270 ◽

Cited By ~ 4

Author(s):

Paulo A. S. Kadri ◽

Jean G. de Oliveira ◽

Niklaus Krayenbühl ◽

Uğur Türe ◽

Evandro P. L. de Oliveira ◽

...

Keyword(s):

White Matter ◽

Anterior Commissure ◽

Anterior Segment ◽

Clinical Manifestations ◽

Fiber Bundles ◽

Surgical Approaches ◽

Middle Temporal Gyrus ◽

Uncinate Fasciculus ◽

Middle Temporal ◽

Temporal Horn

Abstract BACKGROUND: Surgical access to the temporal horn is necessary to treat tumors and vascular lesions, but is used mainly in patients with mediobasal temporal epilepsy. The surgical approaches to this cavity fall into 3 primary categories: lateral, inferior, and transsylvian. The current neurosurgical literature has underestimated the interruption of involved fiber bundles and the correlated clinical manifestations. OBJECTIVE: To delineate the interruption of fiber bundles during the different approaches to the temporal horn. METHODS: We simulated the lateral (trans-middle temporal gyrus), inferior (transparahippocampal gyrus), and transsylvian approaches in 20 previously frozen, formalin-fixed human brains (40 hemispheres). Fiber dissection was then done along the lateral and inferior aspects under the operating microscope. Each stage of dissection and its respective fiber tract interruption were defined. RESULTS: The lateral (trans-middle temporal gyrus) approach interrupted “U” fibers, the superior longitudinal fasciculus (inferior arm), occipitofrontal fasciculus (ventral segment), uncinate fasciculus (dorsolateral segment), anterior commissure (posterior segment), temporopontine, inferior thalamic peduncle (posterior fibers), posterior thalamic peduncle (anterior portion), and tapetum fibers. The inferior (transparahippocampal gyrus) approach interrupted “U” fibers, the cingulum (inferior arm), and fimbria, and transected the hippocampal formation. The transsylvian approach interrupted “U” fibers (anterobasal region of the extreme capsule), the uncinate fasciculus (ventromedial segment), and anterior commissure (anterior segment), and transected the anterosuperior aspect of the amygdala. CONCLUSION: White matter dissection improves our knowledge of the complex anatomy surrounding the temporal horn. Identifying the fiber bundles at risk during each surgical approach adds important information for choosing the appropriate surgical strategy.

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The Unique Fiber Anatomy of Middle Temporal Gyrus Default Mode Connectivity

Operative Neurosurgery ◽

10.1093/ons/opab109 ◽

2021 ◽

Author(s):

Robert G Briggs ◽

Onur Tanglay ◽

Nicholas B Dadario ◽

Isabella M Young ◽

R Dineth Fonseka ◽

...

Keyword(s):

White Matter ◽

Language Processing ◽

Ex Vivo ◽

Diffusion Imaging ◽

Middle Temporal Gyrus ◽

Middle Temporal ◽

Default Mode ◽

Linear Sequence ◽

Human Connectome Project ◽

Association Fibers

Abstract BACKGROUND The middle temporal gyrus (MTG) is understood to play a role in language-related tasks such as lexical comprehension and semantic cognition. However, a more specific understanding of its key white matter connections could promote the preservation of these functions during neurosurgery. OBJECTIVE To provide a detailed description of the underlying white matter tracts associated with the MTG to improve semantic preservation during neurosurgery. METHODS Tractography was performed using diffusion imaging obtained from 10 healthy adults from the Human Connectome Project. All tracts were mapped between cerebral hemispheres with a subsequent laterality index calculated based on resultant tract volumes. Ten postmortem dissections were performed for ex vivo validation of the tractography based on qualitative visual agreement. RESULTS We identified 2 major white matter bundles leaving the MTG: the inferior longitudinal fasciculus and superior longitudinal fasciculus. In addition to long association fibers, a unique linear sequence of U-shaped fibers was identified, possibly representing a form of visual semantic transfer down the temporal lobe. CONCLUSION We elucidate the underlying fiber-bundle anatomy of the MTG, an area highly involved in the brain's language network. Improved understanding of the unique, underlying white matter connections in and around this area may augment our overall understanding of language processing as well as the involvement of higher order cerebral networks like the default mode network in these functions.

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