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Current Opinion in Psychology Oct 2019Cerebellar cortex, which is cytoarchitectonically homogenous, can be functionally differentiated by connectivity differences across the cerebral cortex. The cerebral... (Review)
Review
Cerebellar cortex, which is cytoarchitectonically homogenous, can be functionally differentiated by connectivity differences across the cerebral cortex. The cerebral cortical dorsal attention network exhibits strong, selective connectivity with a set of cerebellar circuits, including lobule VIIb/VIIIa. Recent findings demonstrate that lobule VIIb/VIIIa exhibits functional properties characteristic of the cortical dorsal attention network: task-specific activation; working memory load-dependent responses; and the representation of visuospatial location. Moreover, functional cortico-cerebellar subnetworks exhibit topographic specialization for different aspects of visual attentional processing. Thus, cerebellar lobule VIIb/VIIIa, rather than simply supporting motor functions, appears to be an integral part of the brain's visual attentional circuitry. More generally, these findings suggest that parallel cortico-cerebellar networks may play highly specific functional roles in a broad range of cognitive processes.
Topics: Attention; Brain; Brain Mapping; Cerebral Cortex; Humans; Magnetic Resonance Imaging; Memory, Short-Term; Neural Pathways
PubMed: 31202085
DOI: 10.1016/j.copsyc.2019.05.003 -
Frontiers in Neuroscience 2022Tinnitus is the perception of sound without an external source. The flocculus (FL) and paraflocculus (PFL), which are small lobules of the cerebellum, have recently been...
Tinnitus is the perception of sound without an external source. The flocculus (FL) and paraflocculus (PFL), which are small lobules of the cerebellum, have recently been implicated in its pathophysiology. In a previous study, the volume of the (P)FL-complex correlated with tinnitus severity in patients that had undergone cerebellopontine angle (CPA) tumor removal. In this study, the relation between tinnitus and gray matter volume (GMV) of the (P)FL-complex, GMV of the other cerebellar lobules and GMV of the cerebellar nuclei is investigated in otherwise healthy participants. Data was processed using the SUIT toolbox, which is dedicated to analysis of imaging data of the human cerebellum. GMV of all cerebellar lobules and nuclei were similar between tinnitus and non-tinnitus participants. Moreover, no relation was present between tinnitus severity, as measured by the Tinnitus Handicap Inventory, and (P)FL-complex GMV, tonsil GMV, or total cerebellar cortical GMV. These results suggest that in otherwise healthy participants, in contrast to participants after CPA tumor removal, no relation between the GMV of neither the (P)FL-complex nor other cerebellar lobules and tinnitus presence and severity exists. These findings indicate that a relation only exists when the (P)FL-complex is damaged, for instance by a CPA tumor. Alternatively, it is possible that differences in (P)FL-complex GMVs are too small to detect with a voxel-based morphometry study. Therefore, the role of the (P)FL-complex in tinnitus remains to be further studied.
PubMed: 35573294
DOI: 10.3389/fnins.2022.862873 -
BMC Neuroscience Mar 2022Pituitary adenoma (PA) may compress the optic apparatus, resulting in impaired vision. Some patients can experience improved vision rapidly after surgery. During the...
BACKGROUND
Pituitary adenoma (PA) may compress the optic apparatus, resulting in impaired vision. Some patients can experience improved vision rapidly after surgery. During the early period after surgery, however, the change in neurofunction in the extravisual cortex and higher cognitive cortex has yet to be explored.
OBJECTIVE
Our study focused on the changes in the extravisual resting-state networks in patients with PA after vision restoration.
METHODS
We recruited 14 patients with PA who experienced visual improvement after surgery. The functional connectivity (FC) of 6 seeds [auditory cortex (A1), Broca's area, posterior cingulate cortex (PCC) for the default mode network (DMN), right caudal anterior cingulate cortex for the salience network (SN) and left dorsolateral prefrontal cortex for the executive control network (ECN)] were evaluated. A paired t test was conducted to identify the differences between two groups of patients.
RESULTS
Compared with their preoperative counterparts, patients with PA with improved vision exhibited decreased FC with the right A1 in the left insula lobule, right middle temporal gyrus and left postcentral gyrus and increased FC in the right paracentral lobule; decreased FC with the Broca in the left middle temporal gyrus and increased FC in the left insula lobule and right thalamus; decreased FC with the DMN in the right declive and right precuneus; increased FC in right Brodmann area 17, the left cuneus and the right posterior cingulate; decreased FC with the ECN in the right posterior cingulate, right angular and right precuneus; decreased FC with the SN in the right middle temporal gyrus, right hippocampus, and right precuneus; and increased FC in the right fusiform gyrus, the left lingual gyrus and right Brodmann area 19.
CONCLUSIONS
Vision restoration may cause a response of cross-modal plasticity and multisensory systems related to A1 and the Broca. The DMN and SN may be involved in top-down control of the subareas within the visual cortex. The precuneus may be involved in the DMN, ECN and SN simultaneously.
Topics: Brain; Brain Mapping; Humans; Magnetic Resonance Imaging; Parietal Lobe; Pituitary Neoplasms; Visual Cortex
PubMed: 35300588
DOI: 10.1186/s12868-022-00701-3 -
NeuroImage Aug 2023Tactile and movement-related somatosensory perceptions are crucial for our daily lives and survival. Although the primary somatosensory cortex is thought to be the key...
Tactile and movement-related somatosensory perceptions are crucial for our daily lives and survival. Although the primary somatosensory cortex is thought to be the key structure of somatosensory perception, various cortical downstream areas are also involved in somatosensory perceptual processing. However, little is known about whether cortical networks of these downstream areas can be dissociated depending on each perception, especially in human. We address this issue by combining data from direct cortical stimulation (DCS) for eliciting somatosensation and data from high-gamma band (HG) elicited during tactile stimulation and movement tasks. We found that artificial somatosensory perception is elicited not only from conventional somatosensory-related areas such as the primary and secondary somatosensory cortices but also from a widespread network including superior/inferior parietal lobules and premotor cortex. Interestingly, DCS on the dorsal part of the fronto-parietal area including superior parietal lobule and dorsal premotor cortex often induces movement-related somatosensations, whereas that on the ventral one including inferior parietal lobule and ventral premotor cortex generally elicits tactile sensations. Furthermore, the HG mapping results of the movement and passive tactile stimulation tasks revealed considerable similarity in the spatial distribution between the HG and DCS functional maps. Our findings showed that macroscopic neural processing for tactile and movement-related perceptions could be segregated.
Topics: Cerebral Cortex; Somatosensory Cortex; Touch Perception; Humans; Male; Female; Adolescent; Young Adult; Adult; Motion Perception; Transcranial Direct Current Stimulation; Drug Resistant Epilepsy; Brain Mapping
PubMed: 37245558
DOI: 10.1016/j.neuroimage.2023.120197 -
Scientific Reports Jun 2023Transcutaneous auricular vagus nerve stimulation (taVNS) shows excellent effects on relieving clinical symptoms in migraine patients. Nevertheless, the neurological...
Transcutaneous auricular vagus nerve stimulation (taVNS) shows excellent effects on relieving clinical symptoms in migraine patients. Nevertheless, the neurological mechanisms of taVNS for migraineurs remain unclear. In recent years, voxel-wise degree centrality (DC) and functional connectivity (FC) methods were extensively utilized for exploring alterations in patterns of FC in the resting-state brain. In the present study, thirty-five migraine patients without aura and thirty-eight healthy controls (HCs) were recruited for magnetic resonance imaging scans. Firstly, this study used voxel-wise DC analysis to explore brain regions where abnormalities were present in migraine patients. Secondly, for elucidating neurological mechanisms underlying taVNS in migraine, seed-based resting-state functional connectivity analysis was employed to the taVNS treatment group. Finally, correlation analysis was performed to explore the relationship between alterations in neurological mechanisms and clinical symptoms. Our findings indicated that migraineurs have lower DC values in the inferior temporal gyrus (ITG) and paracentral lobule than in healthy controls (HCs). In addition, migraineurs have higher DC values in the cerebellar lobule VIII and the fusiform gyrus than HCs. Moreover, after taVNS treatment (post-taVNS), patients displayed increased FC between the ITG with the inferior parietal lobule (IPL), orbitofrontal gyrus, angular gyrus, and posterior cingulate gyrus than before taVNS treatment (pre-taVNS). Besides, the post-taVNS patients showed decreased FC between the cerebellar lobule VIII with the supplementary motor area and postcentral gyrus compared with the pre-taVNS patients. The changed FC of ITG-IPL was significantly related to changes in headache intensity. Our study suggested that migraine patients without aura have altered brain connectivity patterns in several hub regions involving multisensory integration, pain perception, and cognitive function. More importantly, taVNS modulated the default mode network and the vestibular cortical network related to the dysfunctions in migraineurs. This paper provides a new perspective on the potential neurological mechanisms and therapeutic targets of taVNS for treating migraine.
Topics: Humans; Migraine without Aura; Vagus Nerve Stimulation; Brain; Headache; Epilepsy
PubMed: 37311825
DOI: 10.1038/s41598-023-36437-1 -
Journal of Integrative Neuroscience Jan 2022The hallmark of Multiple Sclerosis (MS) pathophysiology is the damage to the myelin sheath around axons. The cerebellum is a predilection site for demyelination with a...
The hallmark of Multiple Sclerosis (MS) pathophysiology is the damage to the myelin sheath around axons. The cerebellum is a predilection site for demyelination with a well-recognized role in motor and a rather understudied contribution to cognitive functions. The aim of this study is to investigate patterns of cerebellar grey and white matter pathology, expressed as reduced volume, as well as cortical thickness and their potential contribution to cognitive performance and disability status of patients with MS. 24 patients with MS underwent extensive neuropsychological assessment using paper and pencil tests and the Brain Health Assessment (BHA) tablet-based battery. Cerebellar lobular volumes and thickness were calculated using a volumetric analysis with automated segmentation of the cerebellum and its lobules. The main findings are a reduction of cerebellar grey matter (CGMV) and white matter volumes (CWMV) in lobule X and a widespread cerebellar cortical thinning in patients. Overall disease severity and neurological disability, assessed with the Expanded Disability Status Severity Scale, was correlated with fatigue and information processing speed tasks, but not with CGMV and CWMV. CWMV and CGMV of lobule I-II was negatively correlated with information processing speed, as well as visuospatial memory tests and, finally, inverse cortical thinning associations were noted between the whole cerebellum, lobule I-II, lobule III, lobule VI, Crus I, lobule VIIIA and information processing speed and verbal fluency tasks. The inverse associations observed may represent a compensatory mechanism activated in MS engaging additional high-level cortical areas functionally interconnected with the damaged cerebellum, in order to cope with the cognitive demands of a task.
Topics: Adult; Cerebellar Cortex; Cerebellum; Cognitive Dysfunction; Female; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Multiple Sclerosis; White Matter
PubMed: 35164449
DOI: 10.31083/j.jin2101013 -
National Journal of Maxillofacial... 2022Morphometric studies of the auricle find its place in many areas, such as esthetics, forensic medicine, biology, anthropology, mythology, arts, and acupuncture.
INTRODUCTION
Morphometric studies of the auricle find its place in many areas, such as esthetics, forensic medicine, biology, anthropology, mythology, arts, and acupuncture.
AIMS AND OBJECTIVE
This study aims at establishing the anatomical variations in the auricular dimensions in North Indian population. The objectives of this study were to measure auricle height in males and females, to measure auricle width in both sexes, to measure lobular height (LH) in both sexes, to measure lobular width (LW) in both sexes, to calculate the auricle index in both sexes, and to calculate lobular index in both sexes.
MATERIALS AND METHODS
This study was conducted on 130 subjects (78 males and 52 females), in the age group of 18-25 years, without history of genetic disorders, injuries, or any disease of the auricle.
RESULTS
The average length of the auricle was 6.28 cm (right) and 6.23 cm (left), and the average width was 3.21 cm (right) and 3.28 cm (left). The average height of the lobule was 1.76 cm and 1.77 cm on the right and left sides, respectively, while the lobule width was 1.90 cm on the right side and 2.01 cm on the left side.
CONCLUSION
Total right auricle height and total auricle width of both the right and left ears are more in males as compared to females, and the difference between both the sides was significant. Both right- and left-side LH and LW were higher in males as compared to females.
PubMed: 36051810
DOI: 10.4103/njms.njms_347_21 -
La Clinica Terapeutica Nov 2021The human auricle has attracted the attention of forensic scientists since a long for its unique morphological characteristics. In modern times, these unique features...
The human auricle has attracted the attention of forensic scientists since a long for its unique morphological characteristics. In modern times, these unique features can be captured by CCTV cameras, which may be extremely useful during the identification process in a criminal investigation. Unique morphological characteristics such as Darwin's tubercle, shape, and size of the ear, different morphological features of the helix, tragus, lobule, etc. are frequently used in the identification and individualization process. The human ear was not only accessi-ble for its morphological and morphometric variations, but also its existing bilateral, sex, and population differences. The present study was conducted on 140 individuals (71 males and 69 females) aged between 18 and 30 years. The data were collected from the colleges of Nahan city of Sirmaur district in Himachal Pradesh state of North India. Various anthropometric measurements were taken independently on the left and right ear of each individual with the help of a pair of sliding calipers using a standard method. These linear measurements were physiognomic ear length, physiognomic ear breadth, ear length above tragus, distance from tragus to antihelix, distance from tragus to the helix, lobule height, and lobule width. Auricular index, lobular index, and lobular ear index were calculated from the aforementioned measurements. Further, an independent t-test/ Mann Witney U test and paired sample t-test/ Wilcoxon Signed Rank test were applied for the evaluation of sex differences and bilateral differences in the human ear, respectively. For the prediction of sexual dimorphism, discriminant function analysis was applied. Physiognomic ear length, physiognomic ear breadth, ear length above tragus, distances from tragus to antihelix (left ear only), and tragus to helix exhibited significant sex differences on both sides (p<0.05). Significant bilateral differences (p<0.05) were reported for all the measurements of the ear in males except for lobule height, whereas, significant side differences (p<0.05) were shown for ear length above tragus, distance from tragus to helix, and lobule width among females. The discriminant function model showed 82.10% accuracy for determining sexual dimorphism. The study highlighted sexual dimorphism and bilateral differences in ear morphometry in a north Indian population and provided a database of anthropometric variables in the human ear for forensic and anthropological uses.
Topics: Adolescent; Adult; Anthropometry; Ear, External; Female; Forensic Anthropology; Forensic Medicine; Humans; India; Male; Sex Characteristics; Young Adult
PubMed: 34821348
DOI: 10.7417/CT.2021.2374 -
Communications Biology Apr 2021How do brain size and proportions relate to ecology and evolutionary history? Here, we use virtual endocasts from 38 extinct and extant rodent species spanning 50+...
How do brain size and proportions relate to ecology and evolutionary history? Here, we use virtual endocasts from 38 extinct and extant rodent species spanning 50+ million years of evolution to assess the impact of locomotion, body mass, and phylogeny on the size of the brain, olfactory bulbs, petrosal lobules, and neocortex. We find that body mass and phylogeny are highly correlated with relative brain and brain component size, and that locomotion strongly influences brain, petrosal lobule, and neocortical sizes. Notably, species living in trees have greater relative overall brain, petrosal lobule, and neocortical sizes compared to other locomotor categories, especially fossorial taxa. Across millions of years of Eocene-Recent environmental change, arboreality played a major role in the early evolution of squirrels and closely related aplodontiids, promoting the expansion of the neocortex and petrosal lobules. Fossoriality in aplodontiids had an opposing effect by reducing the need for large brains.
Topics: Animals; Biological Evolution; Brain; Fossils; Locomotion; Sciuridae; Tomography, X-Ray Computed
PubMed: 33846528
DOI: 10.1038/s42003-021-01887-8 -
British Journal of Hospital Medicine... Oct 2022Fibroadenoma is the most common cause of benign breast lumps and is typically seen in women under the age of 40 years. Fibroadenomas are classified as simple, complex,...
Fibroadenoma is the most common cause of benign breast lumps and is typically seen in women under the age of 40 years. Fibroadenomas are classified as simple, complex, giant, myxoid or juvenile. They present as smooth, rubbery, mobile masses on palpation. Ultrasonographic and mammographic features typical of fibroadenomas include solid, round, well-circumscribed masses, with or without lobulated features. They are predominantly treated conservatively although clinical pathways recommend referral for triple assessment. Surgical intervention is indicated by the presence of one or more of the following features: the presence of symptoms, a diameter greater than 2 cm, rapid growth rate, complex features, disease recurrence or patient anxiety.
Topics: Female; Humans; Adult; Fibroadenoma; Mammography; Breast Neoplasms; Records
PubMed: 36322437
DOI: 10.12968/hmed.2022.0070