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PubMed1991

Acute effects of cocaine on spontaneous and discriminative motor functions: relation to route of administration and pharmacokinetics.

Rats administered cocaine i.p. and p.o. (7.5-30 mg/kg) showed dose-related increases in locomotor (LM) and small-movement activities, with LM rates decreasing over the 2-hr session, except at the largest i.p. dose, for which rates were greater in the 2nd hr. Lidocaine p.o. (15-30 mg/kg) did not increase activity. Relating the area under the curve measures for serum cocaine (concentration-time) and LM activity (LM activity-time) for 2 hr postadministration indicated that cocaine was about twice as potent i.p., compared to p.o., in increasing LM activity. Cocaine (i.p. and p.o.) produced dose-related decrements in both discriminative motor control performance and in task work rate, whereas lidocaine p.o. did not. The motor control decrements produced by cocaine were approximately comparable by i.p. and p.o. routes, whereas effects on LM rates were much greater by i.p. than by p.o. administration. The effects of cocaine by both routes on LM rates were proportionally much greater than its effect on motor control performance. Changes in LM rates and motor control performance over the postadministration period were related to the pharmacokinetic features (maximum serum concentration, time to maximum serum concentration and elimination half-life) of cocaine observed for the routes explored (i.p., p.o. and s.c.). Tail-tip serum samples, although yielding conservative estimates of cocaine concentration, correlated well with trunk serum and brain cocaine levels.

Administration, Oral↗

PubMed1997

Hindbrain effects of PACAP on gastric motor function in the rat.

Pituitary adenylate cyclase-activating polypeptide (PACAP)-like immunoreactive cell bodies and fibers are visualized in hindbrain nuclei that are involved in the regulation of autonomic function, yet little is known about the gastric and cardiovascular effects of this peptide in the dorsal vagal complex, nucleus raphe obscurus, and nucleus ambiguus. Therefore, multiple-barreled micropipettes were used to inject PACAP-38 (1-100 pmol) into each of these nuclei in alpha-chloralose anesthetized rats, while intragastric pressure, pyloric and greater curvature smooth muscle contractile activity, blood pressure, and heart rate were recorded. For comparison, the effect of L-glutamate (15 nmol) microinjected into the same sites on gastric motor activity was also assessed. L-Glutamate microinjected into each nucleus before PACAP-38 significantly increased intragastric pressure, both in terms of the peak increase and the total area of the response. Microinjections of PACAP-38 (10 and 100 pmol) into each of the nuclei significantly increased peak intragastric pressure, but the total area of the response was only significantly increased by the highest dose (100 pmol) in the case of the dorsal vagal complex and nucleus raphe obscurus. No consistent changes in heart rate and mean arterial blood pressure were noted after microinjection of PACAP-38 into each of the three nuclei. Bilateral vagotomy abolished the increase in intragastric pressure in response to microinjection of PACAP-38 into the dorsal vagal complex and nucleus raphe obscurus. We conclude that PACAP-38 in the dorsal vagal complex and nucleus raphe obscurus is involved in vagally mediated gastric motor excitation.

Animals↗

PubMedDate not supplied

Manometric assessment of impaired esophageal motor function in primary Sjögren's syndrome.

OBJECTIVE: To evaluate by manometry the esophageal motility changes in patients with primary Sjögren's syndrome (SS). METHODS: Esophageal manometry was carried out in 25 (F/M: 22/3) primary SS patients with systemic manifestations and in 42 control subjects. The primary SS patients also completed a dysphagia scoring questionnaire and underwent whole salivary flow measurements. RESULTS: As compared with the controls the primary SS patients exhibited a decreased lower esophageal sphincter (LES) pressure (P < 0.01) and a prolongation of LES relaxations (P < 0.02). In the esophageal body (EB) a decreased peristaltic velocity (p < 0.01), an increased duration of contractions (p < 0.01) and a higher occurrence of simultaneous waves (p < 0.01) were detected. Since decreased peristaltic velocity was the most frequent motor abnormality (11/25 cases), two groups of patients were formed for further analysis: patients with a decreased (group I, n = 11) and patients with a normal (group II, n = 14) peristaltic velocity. The SS patients with a decreased EB propagation velocity (< or = 2.7 cm/s, group I) displayed more significantly decreased pressures (p < 0.01) and more prolonged relaxation times (p < 0.05) in the LES, with higher rates of simultaneous contractions on dry swallows (p = 0.05) in the EB, as compared with those who had a normal peristaltic velocity (group II). Of the clinical parameters, the decreased EB peristaltic velocity was associated with a smaller whole saliva production both in the basal state and after stimulation. Furthermore, this group of patients had a significantly higher liquid requirement for swallowing than those who had normal peristaltic velocities (p = 0.05). CONCLUSIONS: Primary SS patients with systemic manifestations exhibit several esophageal motility abnormalities. In this study, a decreased EB peristaltic velocity was the most common manometric change, and showed an association with impaired saliva production and higher liquid requirement for swallowing, but not with the laboratory parameters or with the systemic manifestations of the disease.

Adult↗

PubMed1986

Control of human colonic motor function.

Human colonic motility is governed by control mechanisms involving the electrical activity of the smooth muscle cell membranes, the intrinsic and extrinsic nervous activity, and hormonal action. The structural bases for neural and myogenic control have not been demonstrated. However, gap junctions are lacking between muscle cells, and nerves are not close to smooth muscle cells. The myogenic control, as observed in vitro, is described and compared with results obtained from different in vivo techniques. In vitro and in vivo measurements are critically evaluated, and a reconciliation between them attempted. No appropriate animal model is available to help resolve different findings and interpretations. Neural control of colon motility is exerted probably through modulation of myogenic activity as well as directly. The activities of extrinsic nerves, intrinsic motor nerves and afferent nerves are integrated within the colon, at prevertebral ganglia and in the spinal cord in animals, but similar data are not available for the human. There is a lack of studies directly relating transit to motility and conventional beliefs need reexamination.

Animals↗

PubMedDate not supplied

[Effects of early rehabilitative treatment on neurological development and cognitive and perceptual-motor functions of preterm infants at risk].

Longterm effects of early rehabilitative treatment are evaluated in 37 premature infants at neurological risk. The late neurological and psychomotor development of this group of children (experimental group) is compared with that of another 35 at risk premature infants (control group), who received only conventional follow-up care. The two groups do not differ in birth-weight, gestational age, sex and neonatal disorders. At 6 years of age the children of the experimental group have a significantly better neurological status and score higher than the control group, on mean mental indices. They also have lower incidence of neurodevelopmental sequelae (learning disabilities and behaviour problems). However children both in the experimental group and the control group have poor visual-motor integration. Similar results are found also in children, who were low-risk premature infants and who have normal intelligence. Our data suggest that a prescribed early rehabilitative treatment for high-risk preterm infants appears enhance the quality of late development. Treated children have the greatest improvement in all measured outcomes at 6 years (included neurological status, motor and overall development), but do not achieve the same level of neurological and behavioral development as full-term control children. One might question whether the latter finding indicate limited efficacy of early treatment or rather the need to consider separate series of norms for the preterm infant in assessing its outcome. This question requires additional follow-up studies.

Child↗

PubMed1994

[Experimental and clinical studies on lower esophageal sphincter motor function with special reference to the influence of vagal denervation].

Dysmotility of lower esophageal sphincter (LES) is common following gastric surgery. This may result in gastroesophageal reflux which frequently seen following gastric surgery. The aim of this study was to determine the effect of various surgical procedures on esophagogastric motility in dog and human. Esophago-gastric motility was investigated by strain gauge transducers during fasted and fed state in conscious dogs. Motility recordings were performed in three groups of dogs; 1) control dogs, 2) with truncal vagotomized dogs (TV), 3) with selective proximal vagotomized dogs (SPV). In human, manometric recordings were performed before and after gastric surgery (SPV or distal partial gastrectomy). In control animals, lower esophagus and LES contracted simultaneously with each contractions of the stomach during interdigestive motor contractions in fasted state. In fed state, LES showed tonic contractions, while gastric body showed receptive relaxation. These motility pattern of LES was considered to prevent gastroesophageal reflux in both fasted and fed states. These coordinated LES contractions disappeared following SPV or TV. In human, the amplitude and velocity of esophageal propagating contractions deceased after SPV or distal partial gastrectomy. In conclusion, gastric surgeries such as SPV, TV and/or distal partial gastrectomy caused LES dysmotility. These phenomena explain frequent gastroesophageal reflux following gastric surgery. Supplementation of anti-reflux procedure for gastric surgery should be required in the prevention of gastroesophageal reflux following gastric surgery.

Animals↗

PubMed1991

Chronic oral cocaine self-administration: pharmacokinetics and effects on spontaneous and discriminative motor functions.

Rats receiving repeated doses of oral cocaine (15 mg/kg) showed replicable increases in large-movement and small-movement activity rates, but sensitization to the repeated doses did not develop. With a schedule-induction procedure, as the daily, 3-hr, oral dose of self-administered cocaine increased, marked dose-related increases occurred in both large-movement locomotor activity rate and the time for which these elevations were sustained during the following daily 2-hr activity session. Sensitization developed. At the highest levels of self-administered oral cocaine (about 80 mg/kg), post-administration serum cocaine levels remained undiminished for the activity-session period, as did the large-movement activities of most animals, indicating no development of acute tolerance. Rats receiving repeated doses of oral cocaine (15 mg/kg) showed discriminative motor control deficits as well as increases in work rate. These changes were dose-related in animals self-administering oral cocaine under the schedule-induction procedure. Upon withdrawal of cocaine from the schedule-induction animals, motor behavior returned to precocaine base-line performance for most animals. The behavior of the animal with the largest cocaine intake did not return. After a schedule-induced oral cocaine intake session, the tail-tip and trunk serum measures for cocaine and its metabolites were approximately equivalent, while brain cocaine and norcocaine levels remained markedly elevated over serum values.

Animals↗

PubMed1991

Dopamine sulfate in ventricular cerebrospinal fluid and motor function in Parkinson's disease.

We measured sequential plasma and CSF levodopa and CSF dopamine sulfate levels following a single dose of levodopa/carbidopa in two patients with advanced Parkinson's disease (PD). We obtained CSF from an Ommaya reservoir implanted in the lateral ventricle several months earlier at the time of transplantation of adrenal medulla to caudate nucleus and could detect dopamine only in its sulfconjugated form. Peak CSF levodopa and dopamine sulfate levels occurred 1 to 1.5 hours after peak plasma concentration of levodopa. The time course of clinical improvement and worsening correlated precisely with the appearance and disappearance of both levodopa and dopamine sulfate in the CSF. The precise correlation between CSF dopamine sulfate and levodopa indicates that in patients with advanced PD the brain retains some capacity to convert levodopa to dopamine. The transient nature of the correlation between motor fluctuations, CSF levodopa, and CSF dopamine sulfate is consistent with suggestions that in patients with advanced PD there is a diminished capacity to store dopamine synthesized from exogenous levodopa. Dopamine sulfate appears to be a useful index of the availability of dopamine in the parkinsonian brain.

Carbidopa↗

PubMed2003

Dual sensory-motor function for a molluskan statocyst network.

In mollusks, statocyst receptor cells (SRCs) interact with each other forming a neural network; their activity is determined by both the animal's orientation in the gravitational field and multimodal inputs. These two facts suggest that the function of the statocysts is not limited to sensing the animal's orientation. We studied the role of the statocysts in the organization of search motion during hunting behavior in the marine mollusk, Clione limacina. When hunting, Clione swims along a complex trajectory including numerous twists and turns confined within a definite space. Search-like behavior could be evoked pharmacologically by physostigmine; application of physostigmine to the isolated CNS produced "fictive search behavior" monitored by recordings from wing and tail nerves. Both in behavioral and in vitro experiments, we found that the statocysts are necessary for search behavior. The motor program typical of searching could not be produced after removing the statocysts. Simultaneous recordings from single SRCs and motor nerves showed that there was a correlation between the SRCs activity and search episodes. This correlation occurred even though the preparation was fixed and, therefore the sensory stimulus was constant. The excitation of individual SRCs could in some cases precede the beginning of search episodes. A biologically based model showed that, theoretically, the hunting search motor program could be generated by the statocyst receptor network due to its intrinsic dynamics. The results presented support for the idea that the statocysts are actively involved in the production of the motor program underlying search movements during hunting behavior.

Action Potentials↗

PubMed1983

[Effect of motor function disorder on the properties of the muscle fiber membrane].

Experiments on frogs with the use of the microelectrode techniques were made to study the effect of tenotomy and immobilization of a limb with a metal cast in the extension position on the properties of the membrane of muscle fibers. Two weeks after tenotomy there were no changes in the magnitude of the membrane rest potential, input resistance and time constant of the membrane of muscle fibers or in the pattern of its sensitivity to acetylcholine. Two and three weeks after the limb immobilization no changes in the membrane rest potential and passive electrical properties of the muscle membrane were recorded either. However, if the time elapsed after immobilization was 2 and 3 weeks, the zone of the sensitivity of muscle fibers to acetylcholine was slightly greater than in the control. It is suggested that the motor activity in the frog per se is not the determinant of the muscle fiber differentiation preset by the nervous system.

Acetylcholine↗

PubMed1976

[Reflex responses during the early period of recovery of motor function in a transplanted limb].

In immobilized anesthetized rats, monosynaptic reflex responses before and after (3 months) the autoreplantation of the left hind limb were studied. The early period after replantation was characterized by the lowering of excitability, the increase of latency, the decrease of differences between reflex responses to nerves stimulation. Differences existed between responses to stimulation of flexors and extensors but only with a major time summation which suggested that they were due to dendrite processes in chromatotized motoneurons.

Animals↗

PubMed1993

A comparison of (-)-deoxybenzomorphans devoid of opiate activity with their dextrorotatory phenolic counterparts suggests role of sigma 2 receptors in motor function.

Three novel benzomorphans, (+)-N-benzylnormetazocine, (-)-deoxy-N-benzylnormetazocine, and (-)-deoxypentazocine were tested for their ability to produce circling behavior in rats following intranigral microinjections. Dose studies revealed the following rank order of potency: (-)-deoxypentazocine > (-)-deoxy-N-benzylnormetazocine > (+)-N-benzylnormetazocine. This rank order approximates that for affinities for sigma 2 receptors but not sigma 1 receptors. It is very unlikely that the effects of the (-)-deoxybenzomorphans were mediated by opiate receptors for the following reasons: (1) consistent with the known requirement for the phenolic hydroxyl group for opiate activity, both (-)-deoxy compounds showed very low affinity for opiate receptors; (2) naloxone (4 micrograms) co-administered with (-)-deoxy-N-benzylnormetazocine failed to reduce its efficacy; (3) both (-)-deoxy compounds failed to produce marked analgesic effects in the tail flick test following systemic injections of 20 mg/kg s.c. These finding suggest that sigma 2 receptors mediate the motor effects of sigma ligands in rats.

Animals↗

PubMed1995

The effects of low level laser treatment on recovery of nerve conduction and motor function after compression injury in the rat sciatic nerve.

An animal study is presented examining the effect of low level laser (LLL) treatment on nerve regeneration following axonotmesis. Twenty animals received a standardised injury to the right sciatic nerve using a time, load and length sequence (10 min, 150 N, 5 mm) known to cause extensive axonal degeneration of the rat sciatic nerve. The LLL treatment was administered using a hand-held laser probe in light contact with the skin on the dorsal aspect of the hind leg overlying the site of the axonotmesis injury to the sciatic nerve. A group of 10 animals were treated with 6J of LLL (GaAlAs 830 nm) daily for a period of 28 d. Ten more animals were treated daily with a sham exposure setting and served as controls. Nerve function was assessed by a recognised method of walking tract print analysis; the "Sciatic Functional Index" (SFI), and nerve regeneration was assessed by recording the evoked compound action potentials (cAP) in the common peroneal nerve. At 21 d post-injury, the laser-treated group had a significantly lower median SFI than the sham laser-treated group, indicating that the real laser treatment had improved functional recovery in the nerve. However, no differences were found between the evoked cAP parameters that were measured in the laser-treated and sham laser-treated groups. Histological examination reiterated the lack of difference between the two groups. Consequently, the effects of LLL on recovery must have occurred more peripherally to the point measured.

Animals↗

PubMedDate not supplied

[Motor function study in traumatic lesions of the brachial plexus].

The muscular tone of flexors and extensors was studied in dynamics in patients with trauma of the brachial plexus. The study involved measurement of mechanical resistance of a passive limb periodical movements at the elbow joint. The electrogram was registered synchronously with the mechanogram to study the reactions of the agonists and the antagonists. The results made it possible to judge the maintenance of nerve conduction along the efferent and afferent pathways. The method also enabled the authors to determine the degree of disorders and restoration of functioning of the neuro-muscular connections and to reveal the presence of pathological nerve connections which formed as a result of the trauma and interfered with the performance of voluntary movements. The character of the mechanical reaction of the muscles to passive movements allowed judgement of the presence of muscular contractures or stiffness of the joint.

Arm↗

PubMed1993

Physiology of motor function of the sphincter of Oddi.

Human and experimental studies of the sphincter of Oddi have established that the sphincter is not a simple and passive smooth muscle portion of the biliary system; rather, it plays an active role in modulating bile flow into the duodenum in both the fasted and the postprandial states. The sphincter of Oddi in the opossum, and likely in man, demonstrates spontaneous phasic and perhaps peristaltic activity that affects bile flow into the duodenum. The sphincter appears to be under the control of a smooth muscle pacemaking-like region in the proximal sphincter that controls the frequency and direction of propagation of the phasic contractions. Immunohistochemical studies have documented the presence of dense concentrations of neuropeptide-containing myenteric nerves in the sphincter of Oddi. Physiologic studies have confirmed that these peptides, in combination with the classic gastrointestinal hormones, exert significant effects on biliary motility. Experimental studies of the motor physiology of the sphincter of Oddi have advanced our understanding of human biliary motility and dysmotility. A subset of patients experiences biliary-like pain after cholecystectomy. This pain may be attributable to either mechanical stenosis of the papilla or dysfunction of the sphincter of Oddi. No definitive test currently exists to establish the diagnosis with adequate sensitivity or specificity. It is hoped that further development of ultrasonographic, scintigraphic, manometric, or electromyographic techniques will allow a clearer definition of patients who truly have sphincter dysfunction and who might benefit from medical, endoscopic, or surgical therapy.

Animals↗

PubMed1987

Depression of reticulo-ruminal motor functions through the stimulation of alpha 2-adrenoceptors.

Inhibition of the cyclical contractions of the reticulum and the rumen by detomidine (10-40 micrograms/kg, i.v.), xylazine (20-80 micrograms/kg, i.v.) and clonidine (2.5-10 micrograms/kg, i.v.) were compared in sheep and cattle housed individually in box stalls. Two alpha 2-adrenergic receptor blocking agents, tolazoline and yohimbine, were administered intravenously for prevention (0.1-0.4 mg/kg) or reversal (0.4-1.2 mg/kg) of these effects. Continuous recording of the reticuloruminal contractions and measurement of the volume of ruminal gas eliminated through the upper respiratory tract indicated that the three alpha 2-agonists inhibited the primary ruminal contractions associated with the reticular contractions. The occurrence of secondary ruminal contractions was also blocked in sheep, but only suppressed in cattle. The inhibition of reticulo-ruminal contractions was prevented or reversed competitively by the two alpha 2-blocking agents, suggesting an alpha 2-adrenoceptor mediation of the inhibition of cyclical motor activity of the reticulo-rumen. In contrast with tolazoline, yohimbine was unable to alleviate the accumulation of gas resulting from inhibition of the secondary ruminal contractions.

Adrenergic alpha-Agonists↗

PubMed2003

High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients.

Abnormal riboflavin status in the absence of a dietary deficiency was detected in 31 consecutive outpatients with Parkinson's disease (PD), while the classical determinants of homocysteine levels (B6, folic acid, and B12) were usually within normal limits. In contrast, only 3 of 10 consecutive outpatients with dementia without previous stroke had abnormal riboflavin status. The data for 12 patients who did not complete 6 months of therapy or did not comply with the proposed treatment paradigm were excluded from analysis. Nineteen PD patients (8 males and 11 females, mean age +/- SD = 66.2+/-8.6 years; 3, 3, 2, 5, and 6 patients in Hoehn and Yahr stages I to V) received riboflavin orally (30 mg every 8 h) plus their usual symptomatic medications and all red meat was eliminated from their diet. After 1 month the riboflavin status of the patients was normalized from 106.4+/-34.9 to 179.2+/-23 ng/ml (N = 9). Motor capacity was measured by a modification of the scoring system of Hoehn and Yahr, which reports motor capacity as percent. All 19 patients who completed 6 months of treatment showed improved motor capacity during the first three months and most reached a plateau while 5/19 continued to improve in the 3- to 6-month interval. Their average motor capacity increased from 44 to 71% after 6 months, increasing significantly every month compared with their own pretreatment status (P < 0.001, Wilcoxon signed rank test). Discontinuation of riboflavin for several days did not impair motor capacity and yellowish urine was the only side effect observed. The data show that the proposed treatment improves the clinical condition of PD patients. Riboflavin-sensitive mechanisms involved in PD may include glutathione depletion, cumulative mitochondrial DNA mutations, disturbed mitochondrial protein complexes, and abnormal iron metabolism. More studies are required to identify the mechanisms involved.

Aged↗

PubMed1986

Investigation of catecholamine effects on stomach and duodenum motor functions in unanaesthetized dogs.

The aim of this study was to investigate the effects of catecholamines on motility of stomach and intestine in chronic experiments on dogs with fistulas in stomach and duodenum. The contractions of stomach and duodenum were registered by a balloon method. It was established that i.v. adrenaline and noradrenaline injections in dogs with intact vagi inhibited food-induced motility in stomach and duodenum and did not produce contractions in the empty and quiescent gastrointestinal tract. Beta-adrenoagonist isoprenaline on the contrary produced stomach and duodenum contractions in fed dogs during the quiescent period. In fed dogs isoprenaline caused a 3-phasic reaction: a phase of primary short-term suppression of stomach and duodenum motility, a phase of motility increase and a phase of secondary suppression of stomach and duodenum motility. The contractions evoked by isoprenaline in the stomach resemble in amplitude and shape, periodical activities which are typical for fasting dogs. Vagotomy intensified isoprenaline motor effects in hungry and fed dogs and eliminated the phase of primary suppression in fed dogs. The isoprenaline effects were blocked by propranolol, but not by phentolamine. They were decreased more effectively in the stomach by atropine and by hexomethonium in the duodenum.

Animals↗