Search results for " Nerve"
showing 10 items of 885 documents
SETD7 mediates spinal microgliosis and neuropathic pain in a rat model of peripheral nerve injury
2019
Abstract Gene transcription regulation is critical for the development of spinal microgliosis and neuropathic pain after peripheral nerve injury. Using a model of chronic constriction injury (CCI) of the sciatic nerve, this study characterized the role of SET domain containing lysine methyltransferase 7 (SETD7) which monomethylates histone H3 lysine 4 (H3K4me1), a marker for active gene transcription. SETD7 protein expression in the spinal dorsal horn ipsilateral to nerve lesion was increased from one day to 14 days after CCI, concomitantly with the expression of inflammatory genes, Ccl2, Il-6 and Il-1β. The CCI-induced SETD7 expression was predominantly localized to microglia, as demonstra…
Pancreatic polypeptide stimulates mouse gastric motor activity through peripheral neural mechanisms
2016
Background Pancreatic polypeptide (PP) is supposed to be one of the major endogenous agonists of the neuropeptide Y4 receptor. Pancreatic polypeptide can influence gastrointestinal motility, acting mainly through vagal mechanisms, but whether PP acts directly on the stomach has not been explored yet. The aims of this study were to investigate the effects of PP on mouse gastric emptying, on spontaneous tone of whole stomach in vitro and to examine the mechanism of action. Methods Gastric emptying was measured by red phenol method after i.p. PP administration (1–3 nmol per mouse). Responses induced by PP (1–300 mmol L−1) on gastric endoluminal pressure were analyzed in vitro in the presence o…
Backfiring of the isolated rat phrenic nerve does not collide with impulse propagation following repetitive nerve stimulation at 1-50 Hz.
1991
Acetylcholinesterase inhibition with neostigmine in the isolated rat phrenic nerve-hemidiaphragm preparation induced axonal backfiring and repetitive compound muscle action potentials following single nerve stimulation. The duration of backfiring and the repetitive compound muscle action potentials did not exceed 55 ms. With repetitive nerve stimulation at frequencies ranging from 1 to 50 Hz, backfiring was present only with the first stimulus and the amplitude of the second compound muscle action potential was maximally reduced, while the subsequent responses recovered gradually. However, the amplitudes of the concommitant antidromic nerve action potentials remained unchanged during the en…
Acute effects of 15min static or contract-relax stretching modalities on plantar flexors neuromuscular properties
2010
The present study aimed to investigate the immediate effects of 15 min static or sub-maximal contract-relax stretching modalities on the neuromuscular properties of plantar flexor muscles. Ten male volunteers were tested before and immediately after 15 min static or contract-relax stretching programs of plantar flexor muscles (20 stretches). Static stretching consisted in 30s stretches to the point of discomfort. For the contract-relax stretching modality, subjects performed 6s sub-maximal isometric plantar flexion before 24s static stretches. Measurements included maximal voluntary isometric torque (MVT) and the corresponding electromyographic activity of soleus (SOL) and medial gastrocnem…
Inhibitory responses to exogenous adenosine in murine proximal and distal colon”
2006
The aims of the present study were firstly, to characterize pharmacologically the subtypes of P(1) purinoreceptors involved in the inhibitory effects induced by exogenous adenosine in longitudinal smooth muscle of mouse colon, and secondly, to examine differences in the function and distribution of these receptors between proximal and distal colon. Adenosine (100 microM-3 mM) caused a concentration-dependent reduction of the amplitude of spontaneous contractions in the proximal colon, and muscular relaxation in the distal colon. In the proximal colon, adenosine effects were antagonized by a selective A(1) receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10 nM), but were not m…
Changes of the ratio between myelin thickness and axon diameter in human developing sural, femoral, ulnar, facial, and trochlear nerves
1988
Previous studies on sural nerves were extended to human femoral, ulnar, facial and trochlear nerves. As asynchronous development of axon diameter and myelin sheath thickness was noted in all nerves studied. Whereas axons reach their maximal diameter by or before 5 years of age, maximal myelin sheath thickness is not attained before 16-17 years of age, i.e., more than 10 years later. The slope of the regression lines for the ratio between axon diameter and myelin thickness is significantly steeper in older than in younger individuals; it also differs if small and large fibers with more or less than 50 myelin lamellae are evaluated separately. The number of Schmidt-Lanterman incisures during …
Changes of the ratio between myelin thickness and axon diameter in the human developing sural nerve
1978
Axon caliber and myelin sheath thickness of individual nerve fibers were evaluated in the developing human sural nerve using three different methods of measurement: 1. ocular micrometer evaluation of large fibers, 2. photographic enlargements for evaluating large numbers of nerve fibers of all sizes, and 3. electron microscopic enlargements for more precise measurements in selected nerves. The average axonal diameter doubles from 5 months gestation to about 5 years of age. Large fiber group axons increase, during the same period, by a factor of 3--3.5 with a slight decrease thereafter. The myelin thickness increases more slowly, but continuously, between 5 months gestation until the age of …
Muscular performances at the ankle joint in young and elderly men.
2005
The effect of aging on mechanical and electromyographic characteristics of ankle joint muscles was investigated in 11 young (mean age 24 years) and 12 elderly (mean age 77 years) males. Maximal and submaximal isometric voluntary torques were measured during ankle plantarflexion and dorsiflexion. Electromyographic activities of triceps surae and tibialis anterior muscles were recorded. The elderly group developed equal maximal dorsiflexion torques (42 vs 45 N.m, p >.05), but in plantarflexion, the elderly group was weaker (80 vs 132 N.m, p <.001) and presented a decreased twitch amplitude (11 vs 16 N.m) and lower coactivation (8% vs 15%) than that of the young adults. We established a linear…
STIMULATION OF ?1-ADRENOCEPTORS ENHANCES ELECTRICALLY EVOKED [3H]-ACETYLCHOLINE RELEASE FROM RAT PHRENIC NERVE
1990
1. The effects of isoprenaline, noradrenaline and fenoterol on the electrically evoked release of [3H]-acetylcholine from the rat phrenic nerve were investigated. 2. Isoprenaline (0.1 mumol/L) and noradrenaline (1 mumol/L) enhanced evoked [3H]-acetylcholine release by about 90%, an effect which was abolished by CGP 20712A (0.1 mumol/L), a specific antagonist at beta 1-adrenoceptors. Noradrenaline still enhanced [3H]-acetylcholine release in the presence of phentolamine (1 mumol/L). 3. The enhancing effect of both isoprenaline and noradrenaline decreased at prolonged exposure times (24-32 min). A pre-exposure of the tissue to a low concentration (0.01 mumol/L) of isoprenaline prevented the e…