Cerebellar Responses Evoked by Nociceptive Leg Withdrawal Reflex as Revealed by Event-Related fMRI

2003 ◽  
Vol 90 (3) ◽  
pp. 1877-1886 ◽  
Author(s):  
A. Dimitrova ◽  
F. P. Kolb ◽  
H.-G. Elles ◽  
M. Maschke ◽  
M. Forsting ◽  
...  
Keyword(s):  
Mossy Fiber ◽  
Anterior Lobe ◽  
Functional Brain Imaging ◽  
Emg Activity ◽  
Medial Malleolus ◽  
Posterior Lobe ◽  
Withdrawal Reflex ◽  
Lateral Posterior ◽  
Crus I ◽  
Withdrawal Reflexes

The aim of the present study was to examine nociceptive leg withdrawal reflex–related areas in the human cerebellum using event-related functional brain imaging (fMRI). Knowledge about cerebellar areas involved in unconditioned limb withdrawal reflex control has some relevance in understanding data of limb withdrawal reflex conditioning studies. Sixteen healthy adult subjects participated. Nociceptive leg withdrawal reflexes were evoked by electrical stimulation of the left tibial nerve behind the medial malleolus. An event-related fMRI paradigm was applied with a total of 30 stimuli being delivered pseudorandomly during 500 consecutive MR scans. Surface electromyographic (EMG) recordings were performed from the left anterior tibial muscle. Only trials with significant reflex EMG activity were used as active events in fMRI statistical analysis. The specified contrasts compared the active event condition with rest. Leg withdrawal reflex–related areas were located within the vermis, paravermis, and lateral posterior cerebellar hemispheres bilaterally. Vermal and paravermal areas in lobules III/IV in the anterior lobe and in lobule VIII in the posterior lobe agree with the cerebellar representation of climbing and mossy fiber hindlimb afferents and voluntary leg movements. They are likely related to efferent modulation of the leg withdrawal reflex and/or sensory processing of afferent inputs from the reflex and/or the noxious stimulus. Additional activation within vermal lobule VI and hemispheral lobules VI/Crus I may be related to other pain-related processes (e.g., facial grimacing, fear, and startlelike reactions).

scholarly journals The Detailed Organization of the Human Cerebellum Estimated by Intrinsic Functional Connectivity Within the Individual

2020 ◽  
Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Anterior Lobe ◽  
Higher Order ◽  
The Body ◽  
Central Field ◽  
Posterior Lobe ◽  
Multiple Networks ◽  
Crus I ◽  
The Individual ◽  
Functional Connectivity Mri

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While cerebellar organization has been examined in group-averaged data, study of individuals provides an opportunity to discover features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned 31 times). Connectivity to somatomotor cortex showed the expected crossed laterality and topography of the body maps. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended at Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each network could be detected in both individuals, and seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.

scholarly journals The Detailed Organization of the Human Cerebellum Estimated by Intrinsic Functional Connectivity Within the Individual

2020 ◽  
Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Anterior Lobe ◽  
Higher Order ◽  
The Body ◽  
Central Field ◽  
Posterior Lobe ◽  
Multiple Networks ◽  
Depth Study ◽  
Crus I ◽  
The Individual

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While key properties of cerebellar organization have been revealed in group-averaged data, in-depth study of individuals provides an opportunity to discover functional-anatomical features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned across 31 MRI sessions). Connectivity to somatomotor cortex showed the expected crossed laterality and inversion of the body maps between the anterior and posterior lobes. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended near Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks around the Crus I/II apex revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each of these networks could be detected in both individuals, and small seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.

scholarly journals An fMRI Study of Intra-Individual Functional Topography in the Human Cerebellum

2010 ◽  
Vol 23 (1-2) ◽  
pp. 65-79 ◽  
Author(s):  
Catherine J. Stoodley ◽  
Eve M. Valera ◽  
Jeremy D. Schmahmann
Keyword(s):  
Mental Rotation ◽  
Anterior Lobe ◽  
Finger Tapping ◽  
Single Subject ◽  
Posterior Lobe ◽  
Single Individual ◽  
Fmri Study ◽  
Functional Topography ◽  
Crus I ◽  
Verb Generation

Neuroimaging studies report cerebellar activation during both motor and non-motor paradigms, and suggest a functional topography within the cerebellum. Sensorimotor tasks activate the anterior lobe, parts of lobule VI, and lobule VIII, whereas higher-level tasks activate lobules VI and VII in the posterior lobe. To determine whether these activation patterns are evident at a single-subject level, we conducted functional magnetic resonance imaging (fMRI) during five tasks investigating sensorimotor (finger tapping), language (verb generation), spatial (mental rotation), working memory (N-back), and emotional processing (viewing images from the International Affective Picture System). Finger tapping activated the ipsilateral anterior lobe (lobules IV-V) as well as lobules VI and VIII. Activation during verb generation was found in right lobules VII and VIIIA. Mental rotation activated left-lateralized clusters in lobules VII-VIIIA, VI-Crus I, and midline VIIAt. The N-back task showed bilateral activation in right lobules VI-Crus I and left lobules VIIB-VIIIA. Cerebellar activation was evident bilaterally in lobule VI while viewing arousing vs. neutral images. This fMRI study provides the first proof of principle demonstration that there is topographic organization of motor execution vs. cognitive/emotional domains within the cerebellum of a single individual, likely reflecting the anatomical specificity of cerebro-cerebellar circuits underlying different task domains. Inter-subject variability of motor and non-motor topography remains to be determined.

On the content of prolan in the pituitary gland

1934 ◽  
Vol 30 (6) ◽  
pp. 634-634
Author(s):  
P. Badul
Keyword(s):  
Pituitary Gland ◽  
Histological Examination ◽  
Anterior Lobe ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
Posterior Pituitary Lobe

The posterior lobe of the pituitary gland in a bull is free of prolan, while in a human it contains prolan. Only here it can be found in that part of the posterior pituitary lobe adjacent to the anterior lobe. In the bull, too, this part of the pituitary gland is completely free of prolan content. Histological examination shows that in humans, this part of the posterior lobe is crossed by bands of cells from the anterior lobe, which consist exclusively of basophilic cells.

Adaptation to Visuomotor Rotation and Force Field Perturbation Is Correlated to Different Brain Areas in Patients With Cerebellar Degeneration

2009 ◽  
Vol 101 (4) ◽  
pp. 1961-1971 ◽  
Author(s):  
K. Rabe ◽  
O. Livne ◽  
E. R. Gizewski ◽  
V. Aurich ◽  
A. Beck ◽  
...  
Keyword(s):  
Force Field ◽  
Decisive Role ◽  
Anterior Lobe ◽  
Magnetic Resonance Images ◽  
Cerebellar Degeneration ◽  
The Other ◽  
Posterior Lobe ◽  
Visuomotor Rotation ◽  
Dynamic Errors ◽  
And Gender

Although it is widely agreed that the cerebellum is necessary for learning and consolidation of new motor tasks, it is not known whether adaptation to kinematic and dynamic errors is processed by the same cerebellar areas or whether different parts play a decisive role. We investigated arm movements in a visuomotor (VM) rotation and a force field (FF) perturbation task in 14 participants with cerebellar degeneration and 14 age- and gender-matched controls. Magnetic resonance images were used to calculate the volume of cerebellar areas (medial, intermediate, and lateral zones of the anterior and posterior lobes) and to identify cerebellar structure important for the two tasks. Corroborating previous studies, cerebellar participants showed deficits in adaptation to both tasks compared with controls ( P < 0.001). However, it was not possible to draw conclusions from the performance in one task on the performance in the other task because an individual participant could show severe impairment in one task and perform relatively well in the other (ρ = 0.1; P = 0.73). We found that atrophy of distinct cerebellar areas correlated with impairment in different tasks. Whereas atrophy of the intermediate and lateral zone of the anterior lobe correlated with impairment in the FF task (ρ = 0.72, 0.70; P = 0.003, 0.005, respectively), atrophy of the intermediate zone of the posterior lobe correlated with adaptation deficits in the VM task (ρ = 0.64; P = 0.015). Our results suggest that adaptation to the different tasks is processed independently and relies on different cerebellar structures.

scholarly journals Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the6-OHDA Lesioned Rat

1994 ◽  
Vol 5 (2) ◽  
pp. 89-102 ◽  
Author(s):  
Bruce E. Pulford ◽  
Andrea R. Mihajlov ◽  
Howard O. Nornes ◽  
L. Ray Whalen
Keyword(s):  
Spinal Cord ◽  
Glyoxylic Acid ◽  
Reflex Activity ◽  
Emg Activity ◽  
Lumbar Region ◽  
Adrenal Chromaffin Cell ◽  
Electrophysiological Testing ◽  
Withdrawal Reflexes ◽  
6 Hydroxydopamine ◽  
Adrenal Chromaffin

The effects of implantation of cultured adrenal medullary cells on the recovery of neurotransmitter specific reflex activity were studied in the rat spinal cord using electrophysiological testing methods. Cell suspensions of cultured neonatal adrenal medullary chromaffin (AM) cells (which produce catecholamines), or Schwann (Sc) cells (controls) were implanted into the lumbar region of the spinal cord 2 weeks after catecholamine (CA) denervation by intracisternal injection of 6-hydroxydopamine (6-OHDA). All cells were taken from 7 day neonates and cultured for 10 days in the presence of nerve growth factor (NGF). Three months after implantation, the extent of implant-associated recovery of reflex activity was determined by measuring electromyogram (EMG) activity and force associated with the long latency component of the hindlimb withdrawal reflex (which is CA modulated). After the electrophysiological testing, rats were anesthetized, and the spinal cords were rapidly removed and frozen. Spinal cords were sectioned longitudinally, and implanted cells were visualized using glyoxylic acid techniques. Labelled sections were examined to determine cell survival. Results indicate that 1) chromaffin cells survive for 3 months in the segments of the cord into which they have been implanted and 2) rats implanted with AM cells have significantly more forceful withdrawal reflexes than those that received Sc cells or received no implant after lesioning.

scholarly journals Expression of 3 beta-hydroxysteroid dehydrogenase/isomerase in the female rat pituitary

2000 ◽  
Vol 166 (1) ◽  
pp. 95-101 ◽  
Author(s):  
S Vidal ◽  
A Roman ◽  
L Moya ◽  
K Kovacs
Keyword(s):  
Present Report ◽  
Hydroxysteroid Dehydrogenase ◽  
Anterior Lobe ◽  
Female Rats ◽  
Endocrine Function ◽  
Pars Intermedia ◽  
Posterior Lobe ◽  
Female Rat ◽  
Target Organs ◽  
Almost All

3 beta-Hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) catalyses an essential step in the biosynthesis of steroid hormones and is widely distributed in peripheral steroid target organs. The present report describes for first time the expression of this enzyme in the pituitary of female rats. Immunohistochemistry at the light microscopic level was performed on pro-oestrous and ovariectomized rat pituitaries. Immunoreactive cells were scattered and randomly distributed throughout the anterior lobe, whereas cells located in the posterior lobe and pars intermedia were immunonegative. Differences were observed in cell morphology and in the number of 3 beta-HSD-immunopositive cells between ovariectomized and pro-oestrous female rat pituitaries, suggesting that steroidogenic activity is affected by ovarian endocrine function. Apart from adenohypophyseal immunoreactive cells, 3 beta-HSD immunopositivity was also noted in endothelial cells of almost all pituitary capillaries located in the anterior and posterior lobes.

scholarly journals Immunocytochemical demonstration of tissue-type plasminogen activator in endocrine cells of the rat pituitary gland.

1985 ◽  
Vol 101 (1) ◽  
pp. 305-311 ◽  
Author(s):  
P Kristensen ◽  
L S Nielsen ◽  
J Grøndahl-Hansen ◽  
P B Andresen ◽  
L I Larsson ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Endocrine Cells ◽  
Large Population ◽  
Cell Types ◽  
Anterior Lobe ◽  
Tissue Type ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Rat Pituitary

We immunocytochemically stained rat pituitary glands using antibodies against plasminogen activators of the tissue type (t-PA) and the urokinase type (u-PA). A large population of endocrine cells in the anterior lobe of the gland displayed intense cytoplasmic immunoreactivity with anti-t-PA. In some areas of the intermediate lobe we found a weak staining, and we observed weakly staining granular structures in the posterior lobe. Controls included absorption of the antibodies with highly purified t-PA. In addition, SDS PAGE followed by immunoblotting of pituitary gland extracts revealed only one band with an electrophoretic mobility similar to that of t-PA when stained with anti-t-PA IgG. No u-PA immunoreactivity was detected in the rat pituitary gland. Sequential staining experiments using antibodies against growth hormone and t-PA demonstrated that the t-PA-immunoreactive cells constitute a large subpopulation of the growth hormone-containing cells. These findings represent the first direct evidence for the presence of t-PA in cell types other than endothelial cells in the intact normal organism. In this article we discuss the implications of the results for a possible role of t-PA in the posttranslational processing of prohormones.

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