scholarly journals Vagal and spinal mechanosensors in the rat stomach and colon have multiple receptive fields

2001 ◽  
Vol 280 (5) ◽  
pp. R1371-R1381 ◽  
Author(s):  
Hans-Rudolf Berthoud ◽  
Penny A. Lynn ◽  
L. Ashley Blackshaw
Keyword(s):  
Receptive Fields ◽  
Splanchnic Nerve ◽  
Distal Colon ◽  
Chemical Information ◽  
Visceral Sensation ◽  
Motor Patterns ◽  
Vagal Nerves ◽  
The Central Nervous System ◽  
Perifusion System

Mechano- and chemosensitive extrinsic primary afferents innervating the gastrointestinal tract convey important information regarding the state of ingested nutrients and specific motor patterns to the central nervous system via splanchnic and vagal nerves. Little is known about the organization of peripheral receptive sites of afferents and their correspondence to morphologically identified terminal structures. Mechano- and chemosensory characteristics and receptive fields of single vagal fibers innervating the stomach as well as lumbar splanchnic nerves innervating the distal colon were identified using an in vitro perifusion system. Twenty-three (17%) of one-hundred thirty-six vagal units identified were found to have multiple, punctate receptive fields, up to 35 mm apart, and were distributed throughout the stomach. Evidence was based on similarity of generated spike forms, occlusion, and latency determinations. Most responded with brief bursts of activity to mucosal stroking with von Frey hairs (10–200 mg) but not to stretch, and 32% responded to capsaicin (10−5M). They were classified as rapidly adapting mucosal receptors. Four (8%) of fifty-three single units recorded from the lumbar splanchnic nerve had more than one, punctate receptive field in the distal colon, up to 40 mm apart. They responded to blunt probing, particularly from the serosal side, and variously to chemical stimulation with 5-hydroxytryptamine and capsaicin. We conclude that a proportion of gastrointestinal mechanosensors has multiple receptive fields and suggest that they integrate mechanical and chemical information from an entire organ, constituting the generalists in visceral sensation.

H2O2 sensitivity of afferent splanchnic C fiber units in vitro

1996 ◽  
Vol 76 (1) ◽  
pp. 371-380 ◽  
Author(s):  
D. W. Adelson ◽  
J. Y. Wei ◽  
L. Kruger
Keyword(s):  
Receptive Fields ◽  
Splanchnic Nerve ◽  
Mechanical Stimuli ◽  
H2o2 Treatment ◽  
Response Latencies ◽  
C Fibers ◽  
Afferent Fibers ◽  
Unit Impulse ◽  
Species Production

1. Single-unit impulse activity evoked by transient, focal application of hydrogen peroxide (H2O2) to identified visceral receptive fields has been characterized in an in vitro rat splanchnic nerve-mesentery preparation. In addition to H2O2 responsiveness, units were characterized in terms of sensitivity to mechanical stimuli, warming, and bradykinin. 2. Mesenteric receptive fields of single splanchnic afferent C fibers in vitro were located with the use of warm (approximately 45 degrees C saline) or mechanical search stimuli. After delimitation of the warm-sensitive and/or mechanosensitive receptive field, units were tested for responsiveness to transient, focal application of H2O2. Microliter volumes (usually 1 microliter) of H2O2 (88-880 mM) evoked responses in 25 of 42 (60%) units with identified warm-sensitive and/or mechanosensitive receptive fields, and in an additional 10 units for which H2O2 was the only effective stimulus. 3. Tachyphylaxis to repeated H2O2 stimulation was observed with interstimulus intervals <30 min, but did not indicate irreversible inactivation of the terminal, because 1) during this period warm and mechanical stimuli elicited responses equal to or greater than those before H2O2 treatment, and 2) H2O2 sensitivity was restored after units were allowed to recover. 4. Eight units unresponsive to an initial dose of H2O2 responded vigorously to a repeated application at the same site, suggesting a potentiating effect of prior H2O2 exposure. 5. Sixty-two percent (8 of 13) of H2O2-responsive units, but no (0 of 6) H2O2-unresponsive units responded to transient, focal bradykinin (9-90 nM) application. 6. An indirect mode of H2O2-evoked afferent excitation in some units was suggested by several observations, including the prolonged (up to 8 min) duration of the response of some units to transient H2O2 application, and the occasionally long (>2 min) response latencies to focal application of H2O2 to defined receptive fields. 7. Excitation of splanchnic neurons by H2O2 may be relevant to the modulation of reactive oxygen species production by immunocompetent cells, because sensory neuropeptides contained in these afferent fibers are known to influence the respiratory burst of macrophages and neutrophils.

An In vitro distal colon-inferior splanchnic nerve preparation: Single unit responses to colorectal distension and bradykinin

2001 ◽  
Vol 120 (5) ◽  
pp. A328
Author(s):  
Jen Yu Wei ◽  
Yu Hua Wang ◽  
James A. McRoberts ◽  
Ameran A. Mayer
Keyword(s):  
Single Unit ◽  
Splanchnic Nerve ◽  
Distal Colon ◽  
Colorectal Distension

The depressing (negative) effect of oestradiol benzoate on the in vitro secretion of LH and FSH by the pituitary gland of the LRH-pretreated long-term ovariectomized rat changes into the augmentative (positive) effect after discontinuation of the LRH-pretreatment

1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter
Keyword(s):  
Depressing Effect ◽  
Ovx Rats ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate ◽  
Negative Effect ◽  
Positive Effect ◽  
Perifusion System

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.

Effect of [Asu,]eel calcitonin on prolactin release in normal subjects and patients with prolactinoma

1985 ◽  
Vol 108 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Hidesuke Kaji ◽  
Kazuo Chihara ◽  
Naoto Minamitani ◽  
Hitoshi Kodama ◽  
Tetsuya Kita ◽  
...  
Keyword(s):  
Body Weight ◽  
Bolus Injection ◽  
Normal Subjects ◽  
Regular Insulin ◽  
Prolactin Release ◽  
Saline Administration ◽  
The Central Nervous System ◽  
Plasma Prl ◽  
Male Subjects

Abstract. The effect of [Asu]eel calcitonin (ECT), an equipotent analogue of eel CT, on prolactin (Prl) secretion was examined in 12 healthy male subjects and in 6 patients with prolactinoma. In healthy subjects, ECT (0.5 μg/kg body weight · h) or saline was infused for 2 h and TRH was injected iv as a bolus of 500 μg at 1 h of ECT or saline administration. ECT did not affect basal Prl levels during 1 h of infusion. TRH caused a significant increase of plasma Prl with peak values of 75.2 ± 11.6 ng/ml in ECT-infused subjects, which did not differ from those infused with saline (68.5 ± 8.3 ng/ml). Next, an iv bolus injection of regular insulin (0.1 U/kg body weight) was followed by an infusion of ECT or saline alone. Plasma Prl peaks after hypoglycaemic stress were significantly lower in ECT-infused subjects than those in saline-injected controls (ECT, 16.5 ± 3.1 vs 33.5 ± 9.6 ng/ml, P < 0.05). In patients with prolactinoma, basal levels of plasma Prl ranging from 42.0–4130 ng/ml failed to change during iv infusion of ECT. Moreover, ECT (10−9–10−6m) did not affect Prl release from prolactinoma tissues perifused in vitro. These findings suggest that ECT may not act directly on the pituitary to modify Prl release. Rather, peripherally administered ECT appears to suppress Prl release via the central nervous system.

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

scholarly journals Beyond Oncological Hyperthermia: Physically Drivable Magnetic Nanobubbles as Novel Multipurpose Theranostic Carriers in the Central Nervous System

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2104 ◽  
Author(s):  
Eleonora Ficiarà ◽  
Shoeb Anwar Ansari ◽  
Monica Argenziano ◽  
Luigi Cangemi ◽  
Chiara Monge ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tumors ◽  
Ad Hoc ◽  
Superparamagnetic Iron Oxide ◽  
Conventional Radiotherapy ◽  
The Central Nervous System ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic Oxygen-Loaded Nanobubbles (MOLNBs), manufactured by adding Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on the surface of polymeric nanobubbles, are investigated as theranostic carriers for delivering oxygen and chemotherapy to brain tumors. Physicochemical and cyto-toxicological properties and in vitro internalization by human brain microvascular endothelial cells as well as the motion of MOLNBs in a static magnetic field were investigated. MOLNBs are safe oxygen-loaded vectors able to overcome the brain membranes and drivable through the Central Nervous System (CNS) to deliver their cargoes to specific sites of interest. In addition, MOLNBs are monitorable either via Magnetic Resonance Imaging (MRI) or Ultrasound (US) sonography. MOLNBs can find application in targeting brain tumors since they can enhance conventional radiotherapy and deliver chemotherapy being driven by ad hoc tailored magnetic fields under MRI and/or US monitoring.

scholarly journals Effects of Platelet-Rich Plasma on Cellular Populations of the Central Nervous System: The Influence of Donor Age

2021 ◽  
Vol 22 (4) ◽  
pp. 1725
Author(s):  
Diego Delgado ◽  
Ane Miren Bilbao ◽  
Maider Beitia ◽  
Ane Garate ◽  
Pello Sánchez ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cellular Response ◽  
Platelet Rich Plasma ◽  
Biological Response ◽  
In Vitro Models ◽  
Molecular Composition ◽  
Cellular Models ◽  
The Central Nervous System

Platelet-rich plasma (PRP) is a biologic therapy that promotes healing responses across multiple medical fields, including the central nervous system (CNS). The efficacy of this therapy depends on several factors such as the donor’s health status and age. This work aims to prove the effect of PRP on cellular models of the CNS, considering the differences between PRP from young and elderly donors. Two different PRP pools were prepared from donors 65–85 and 20–25 years old. The cellular and molecular composition of both PRPs were analyzed. Subsequently, the cellular response was evaluated in CNS in vitro models, studying proliferation, neurogenesis, synaptogenesis, and inflammation. While no differences in the cellular composition of PRPs were found, the molecular composition of the Young PRP showed lower levels of inflammatory molecules such as CCL-11, as well as the presence of other factors not found in Aged PRP (GDF-11). Although both PRPs had effects in terms of reducing neural progenitor cell apoptosis, stabilizing neuronal synapses, and decreasing inflammation in the microglia, the effect of the Young PRP was more pronounced. In conclusion, the molecular composition of the PRP, conditioned by the age of the donors, affects the magnitude of the biological response.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

scholarly journals Design and In Vitro Study of a Dual Drug-Loaded Delivery System Produced by Electrospinning for the Treatment of Acute Injuries of the Central Nervous System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 848
Author(s):  
Luisa Stella Dolci ◽  
Rosaria Carmela Perone ◽  
Roberto Di Gesù ◽  
Mallesh Kurakula ◽  
Chiara Gualandi ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Delivery System ◽  
Synergistic Effects ◽  
In Vitro Release ◽  
Health Priorities ◽  
The Central Nervous System ◽  
Vitro Release ◽  
Dual Drug

Vascular and traumatic injuries of the central nervous system are recognized as global health priorities. A polypharmacology approach that is able to simultaneously target several injury factors by the combination of agents having synergistic effects appears to be promising. Herein, we designed a polymeric delivery system loaded with two drugs, ibuprofen (Ibu) and thyroid hormone triiodothyronine (T3) to in vitro release the suitable amount of the anti-inflammation and the remyelination drug. As a production method, electrospinning technology was used. First, Ibu-loaded micro (diameter circa 0.95–1.20 µm) and nano (diameter circa 0.70 µm) fibers were produced using poly(l-lactide) PLLA and PLGA with different lactide/glycolide ratios (50:50, 75:25, and 85:15) to select the most suitable polymer and fiber diameter. Based on the in vitro release results and in-house knowledge, PLLA nanofibers (mean diameter = 580 ± 120 nm) loaded with both Ibu and T3 were then successfully produced by a co-axial electrospinning technique. The in vitro release studies demonstrated that the final Ibu/T3 PLLA system extended the release of both drugs for 14 days, providing the target sustained release. Finally, studies in cell cultures (RAW macrophages and neural stem cell-derived oligodendrocyte precursor cells—OPCs) demonstrated the anti-inflammatory and promyelinating efficacy of the dual drug-loaded delivery platform.

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