scholarly journals Investigation of multi-site micro recordings of subthalamic nucleus neurons using machine learning MER with DBS in Parkinson`s – A simulation study

2022 ◽  
Vol 7 (4) ◽  
pp. 287-291
Author(s):  
Venkateshwarla Rama Raju
Keyword(s):  
Data Clustering ◽  
Cell Layer ◽  
Statistical Test ◽  
Electrode Site ◽  
Damping Factor ◽  
Volume Conduction ◽  
Identified Neuron ◽  
Vector Computing ◽  
Spike Bursts ◽  
Electrode Point

Multineural spikes were acquired with a multisite electrode placed in the hippocampus pyramidal cell layer of non-primate anesthetized snitch animals. If the impedance of each electrode-site is relatively low and the distance amongst electrode sites is appropriately miniatured, a spike generated by a neuron is parallelly recorded at multielectrode sites with different amplitudes. The covariance between the spike of the at each electrode-point and a template was computed as a damping-factor due to the volume conduction of the spike from the neuron to electrode-site. Computed damping factors were vectorized and analyzed by simple but elegant hierarchical-clustering using a multidimensional statistical-test. Since a cluster of damping vectors was shown to correspond to an antidromically identified neuron, spikes of distinct neurons are classified by suggesting to the scatterings of damping vectors. Errors in damping vector computing due to partially overlapping spikes were minimized by successively subtracting preceding spikes from raw data. Clustering errors due to complex-spike-bursts (i.e., spikes with variable-amplitudes) were prevented by detecting such bursts and using only the first spike of a burst for clustering.

Changes in colonic myoelectric spiking activity during stimulation by bisacodyl

1986 ◽  
Vol 64 (1) ◽  
pp. 39-43 ◽  
Author(s):  
J. C. Schang ◽  
M. Hémond ◽  
M. Hébert ◽  
M. Pilote
Keyword(s):  
Considerable Increase ◽  
Flexible Sigmoidoscopy ◽  
Anal Verge ◽  
Colonic Transit ◽  
Electrode Site ◽  
Complete Suppression ◽  
Bipolar Electrodes ◽  
Before And After ◽  
Spike Bursts ◽  
Spiking Activity

The purpose of this study was to determine some relationships between colonic myoelectric spiking activity and intraluminal propulsion when colonic peristalsis was stimulated by bisacodyl. Myoelectric recordings were obtained in 12 subjects by means of a 50 cm long Silastic tube equipped with four bipolar electrodes fixed at 10-cm intervals. The tube was introduced into the left colon by flexible sigmoidoscopy and the electrodes were located at 50, 40, 30, and 20 cm from the anal verge. A small polyethylene catheter opening at the proximal end of the Silastic tube was used for introducing the laxative into the colon. One hour recording sessions were obtained before and after bisacodyl administration (5 mL of 0.4% solution). The control tracings showed that colonic spiking activity was made of rhythmic stationary bursts that ocurred at only one electrode site and of sporadic bursts that were either propagating over the whole colonic segment or nonpropagating. Administration of bisacodyl was followed by (i) complete suppression of the rhythmic stationary activity; (ii) a considerable increase in the sporadic spiking activity, propagating as well as nonpropagating; (iii) the occurrence of abdominal cramps and urgency to defecate, both associated with the propagating sporadic spike bursts. It is concluded that colonic propulsion induced by bisacodyl may be dependent upon the production of the sporadic bursts, particularly the propagating ones, while the rhythmic stationary bursts do not seem to play a significant role in colonic transit.

Stimulation of colonic peristalsis by vasopressin: electromyographic study in normal subjects and patients with chronic idiopathic constipation

1987 ◽  
Vol 65 (10) ◽  
pp. 2137-2141 ◽  
Author(s):  
Jean-Claude Schang ◽  
Michel Dapoigny ◽  
Ghislain Devroede
Keyword(s):  
Control Period ◽  
Colonic Motility ◽  
Normal Subjects ◽  
Electrode Site ◽  
Idiopathic Constipation ◽  
Chronic Idiopathic Constipation ◽  
Recording Session ◽  
Different Types ◽  
Before And After ◽  
Spike Bursts

The effects of vasopressin on colonic motility were investigated in 6 healthy subjects and 10 patients with chronic idiopathic constipation. Recordings of the colonic myoelectric spiking activity were performed by means of 50-cm long silastic tube, equipped with four bipolar ring electrodes fixed at 10-cm intervals, which was introduced by flexible colonoscopy into the left colon. Tracings were obtained for 1 h in the fasting state and for another hour after an intramuscular injection of a pharmacological dose of vasopressin (0.3 U/kg). The different types of spike bursts generated by the colonic smooth muscle were compared before and after vasopressin injection. In both controls and patients, the tracings showed (i) rhythmic stationary spike bursts (RSB) that were seen at only one electrode site; and (ii) sporadic bursts that were either propagating over all four electrodes (SPB) or nonpropagating (SNPB). Injection of vasopressin in controls was followed for 30 min by a significant increase in the number of propagating bursts from 2.7 ± 0.6 (mean ± SEM) to 5.2 ± 1.4 bursts (p < 0.05); RSB and SNPB were not altered by vasopressin. In the constipated patients, the number of propagating bursts during the control period was significantly lower (0.8 ± 0.2 bursts/30 min) than in the volunteers (p < 0.05). After vasopressin, there was a significant increase to 3.6 ± 0.8 bursts/30 min(p < 0.001); RSB and SNPB also did not show significant alteration after vasopressin. Finally, 4 out of the 10 patients passed stools during the recording session. Since propagating bursts are known to be associated with colonic propulsion, these results indicate that vasopressin at pharmacological doses may stimulate colonic peristalsis and therefore, may be useful in the treatment of some severe idiopathic constipations.

Diverse Synaptic Connections Between Peptidergic Radula Mechanoafferent Neurons and Neurons in the Feeding System ofAplysia

2000 ◽  
Vol 83 (3) ◽  
pp. 1605-1620 ◽  
Author(s):  
Steven C. Rosen ◽  
Mark W. Miller ◽  
Colin G. Evans ◽  
Elizabeth C. Cropper ◽  
Irving Kupfermann
Keyword(s):  
Motor Neurons ◽  
Synaptic Connections ◽  
Buccal Ganglion ◽  
Motor Programs ◽  
Rhythmic Motor ◽  
Identified Neuron ◽  
Low Threshold ◽  
Sensory Responses ◽  
Fast Chemical ◽  
Spike Bursts

The buccal ganglion of Aplysia contains a heterogeneous population of peptidergic, radula mechanoafferent (RM) neurons. To investigate their function, two of the larger RM cells (B21, B22) were identified by morphological and electrophysiological criteria. Both are low-threshold, rapidly adapting, mechanoafferent neurons that responded to touch of the radula, the structure that grasps food during ingestive and egestive feeding movements. Sensory responses of the cells consisted of spike bursts at frequencies of 8–35 Hz. Each cell was found to make chemical, electrical, or combined synapses with other sensory neurons, motor neurons and interneurons involved in radula closure and/or protraction-retraction movements of the odontophore. Motor neurons receiving input included the following: B8a/b, B15, and B16, which innervate muscles contributing to radula closing; and B82, a newly identified neuron that innervates the anterodorsal region of the I1/I3 muscles of the buccal mass. B21 and B22 can affect buccal motor programs by way of their connections to interneurons such as B19 and B64. Fast, chemical, excitatory postsynaptic potentials (EPSPs) produced by RM neurons, such as B21, exhibited strong, frequency-dependent facilitation, a form of homosynaptic plasticity. Firing B21 also produced a slow EPSP in B15 that increased the excitability of the cell. Thus a sensory neuron mediating a behavioral response may have modulatory effects. The data suggest multiple functions for RM neurons including 1) triggering of phase transitions in rhythmic motor programs, 2) adjusting the force of radula closure, 3) switching from biting to swallowing or swallowing to rejection, and 4) enhancing food-induced arousal.

SEM of Hepatocytes and Biliary Passages in Goldfish Liver

1977 ◽  
Vol 35 ◽  
pp. 556-557
Author(s):  
Waykin Nopanitaya ◽  
Joe W. Grisham ◽  
Johnny L. Carson
Keyword(s):  
Carassius Auratus ◽  
Cell Layer ◽  
Three Dimensional ◽  
Cell Types ◽  
Biliary System ◽  
Fish Food ◽  
Commercial Fish ◽  
Goldfish Carassius Auratus ◽  
Commercial Fish Food

An interesting feature of the goldfish liver is the morphology of the hepatic plate, which is always formed by a two-cell layer of hepatocytes. Hepatic plates of the goldfish liver contain an infrequently seen second type of cell, in the centers of plates between two hepatocytes. A TEH study by Yamamoto (1) demonstrated ultrastructural differences between hepatocytes and centrally located cells in hepatic plates; the latter were classified as ductule cells of the biliary system. None of the previous studies clearly showed a three-dimensional organization of the two cell types described. In the present investigation we utilize SEM to elucidate the arrangement of hepatocytes and bile ductular cells in intralobular plates of goldfish liver.Livers from young goldfish (Carassius auratus), about 6-10 cm, fed commercial fish food were used for this study. Hepatic samples were fixed in 4% buffered paraformaldehyde, cut into pieces, fractured, osmicated, CPD, mounted Au-Pd coated, and viewed by SEM at 17-20 kV. Our observations were confined to the ultrastructure of biliary passages within intralobular plates, ductule cells, and hepatocytes.

Anchoring Fibrils in Arterial Endothelium

1969 ◽  
Vol 27 ◽  
pp. 274-275
Author(s):  
A. Trillo
Keyword(s):  
Carotid Arteries ◽  
Animal Species ◽  
Cell Layer ◽  
Present Communication ◽  
Internal Elastic Lamina ◽  
Endothelial Cell Layer ◽  
Structural Details ◽  
Rats And Mice ◽  
Arterial Endothelium ◽  
Elastic Lamina

There are conflicting reports regarding some fine structural details of arteries from several animal species. Buck denied the existence of a sub-endothelial space, while Karrer and Keech described a space of variable width which separates the endothelium from the underlying internal elastic lamina in aortas of aging rats and mice respectively.The present communication deals with the ultrastrueture of the interface between the endothelial cell layer and the internal elastic lamina as observed in carotid arteries from rabbits of varying ages.

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

1453: Lonidamine Reduces Prostate Weight in Rodents and is Accompanied by Apoptosis and Disruption of the Epithelial Cell Layer

2006 ◽  
Vol 175 (4S) ◽  
pp. 469-469
Author(s):  
W. Steve Ammons ◽  
Tatyana Lukoyanova ◽  
Amber Durnal ◽  
Geoffrey Del Rosario ◽  
Alan Colowick
Keyword(s):  
Epithelial Cell ◽  
Cell Layer ◽  
Prostate Weight ◽  
Epithelial Cell Layer

Self-Damping Mechanism in Blood Coagulation

1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Calcium Ions ◽  
Control Mechanism ◽  
Factor Vii ◽  
Damping Factor ◽  
Factor V ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Two Systems

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.

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