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PubMed1998

An electromechanical testing device for assessment of hand motor function.

Instrumentation was designed and constructed to assess the strength and function of the intrinsic muscles of the index and long fingers of the hand. The device consisted of two beams instrumented with strain gages, signal conditioners, and a microprocessor-based embedded controller. A study conducted on four weak spinal cord injury (SCI), three nonweak SCI, and 21 control subjects demonstrated a trend of reduced maximum pinching force between the index and long fingers in weak SCI subjects compared with the other two groups. Weak SCI subjects also demonstrated a significantly slower rapid alternating movement speed of the index finger compared with the other two groups. The instrument has potential use as a clinical tool for quantitative evaluation of the progression of hand motor dysfunction.

Biomechanical Phenomena↗

PubMed1988

Protein redistribution diet restores motor function in patients with dopa-resistant "off" periods.

Sixteen parkinsonians with acquired drug-resistant "off" periods without dyskinesia were placed on a diet in which virtually all protein was concentrated in the evening meal. Restoration of sensitivity to levodopa resulted in 88%. Ten patients (62%) have continued to comply with the diet for 7 months (mean). Two patients were studied in detail. Immobility correlated with elevated plasma levels of large neutral amino acids (LNAA), normality with low LNAA.

Amino Acids↗

PubMed1978

Autosomal dominant system degeneration in Portuguese families of the Azores Islands. A new genetic disorder involving cerebellar, pyramidal, extrapyramidal and spinal cord motor functions.

We studied 40 patients in 15 families from the Portuguese Azores Islands. Each family was affected by an autosomal dominant genetic disorder. Symptoms began between ages 20 and 50. Ataxia, ophthalmoplegia, pyramidal signs, dystonia, rigidity, and distal atrophy were the major clinical findings. Evidence suggested that this was a single genetic disease, with variable phenotypic expression. Machado disease, nigrospinodentatal degeneration with nuclear ophthalmoplegia, and autosomal dominant striatonigral degeneration may be variations of this same genetic disease.

Adult↗

PubMed1980

[Motor functions in developmental-neurological diagnosis. Longitudinal study of low-risk infants. I. Normalization tendency, reflexes].

In a prospective longitudinal study, we investigated 91 low-risk infants on five occasions up to the end of their first year of life. We see that also after low-risk delivery, only four infants showed optimal neurological functions but it was shown too, that borderline-symptoms of the neonatal period have a clear tendency to normalize. We have selected some reflex-mechanisms in infancy and presented their changes. In comparison with other reports, we found that important differences between the results are dependent on techniques of examination and evaluation. The changes in reflex-mechanisms provide an insufficient basis therefore for developmental diagnosis (see second part).

Child Development↗

PubMed1985

Substantia nigra projection to medullary reticular formation: relevance to oculomotor and related motor functions in the cat.

Wheat germ lectin-horseradish peroxidase was injected into the medial medullary reticular formation in 4 cats. Retrogradely labeled cell bodies were observed in the ipsilateral substantia nigra pars reticulata and bilaterally in the superior colliculus, oculomotor nucleus and fastigial nucleus of the cerebellum. The nigral projection to this reticular formation area, which receives diffuse afferents from cortex, cerebellum, oculomotor system and vestibular nucleus and projects to spinal cord, may be of some relevance in understanding the nigral role in postural, head- and eye-movement control.

Animals↗

PubMed1997

Transition from growth cone to functional motor nerve terminal in Drosophila embryos.

As a motor axon grows from the CNS to its target muscle, the terminal has the form of a flattened growth cone with a planar central region, lamellipodia, and filopodia. A mature terminal usually has a stereotyped shape that may be elongated with varicosities, as in several invertebrate species, or have short branches with boutons, as in mammals. We examined in Drosophila the developmental changes between growth cone and mature terminal using ultrastructural and immunocytochemical methods. The transition period, which occurs 2-3 hr after the first growth cone reaches its target muscle, is marked by the formation of "prevaricosities," smoothly contoured enlargements of the axons at the point where the nerve trunk first contacts the muscle fiber (MF). There is a 15-30 min ventral-to-dorsal gradient in the formation of prevaricosities on the individual abdominal MFs. Multineuronal innervation of each MF has occurred by this time, and two or more different axons undergo prevaricosity formation while they are intimately intertwined at the nerve entry point (NEP). Presynaptic active zones, both nerve-nerve and nerve-muscle, occur within the prevaricosities along broad contact regions. Synaptotagmin immunoreactive clusters form concurrently. The first varicosities then develop as a result of constrictions of the larger prevaricosities rather than as enlargement of discrete portions of the filopodia or neurites. The prevaricosity stage therefore may include the key steps that lead to the differentiation of functional differences in terminal subtypes as well as those leading to the formation of a stable neuromuscular junction.

Abdominal Muscles↗

PubMed1987

Effect of aging on striatal dopamine receptor subtype recovery following N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline blockade and relation to motor function in Wistar rats.

Recovery of D1- and D2-dopamine receptors in Wistar rat corpora striata were assessed following N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ blockade). Absolute recovery declines during senescence approximately 25 and 40% for the D1- and D2-subtypes, respectively. Net biosynthetic reductions are comparable to the overall age-related decreases in receptor concentrations for this rat strain. EEDQ administration also induces catalepsy behavior and impairs ability of animals to remain on an inclined screen. Recovery of inclined screen performance is also reduced with age, but is not strictly proportional to recovery of receptor concentrations.

Aging↗

PubMed1985

Separation of the associative and non-associative effects of brain serotonin released by p-chloroamphetamine: dissociable serotoninergic involvement in avoidance learning, pain and motor function.

p-Chloramphetamine (PCA, 0.63-5 mg/kg IP) injected 30-60 min before testing produced a dose-related impairment of avoidance acquisition, prolonged reaction time in the hot-plate test and increased locomotor activity. Pretreatment with the selective serotonin (5-HT) uptake inhibitor zimeldine (10 mg/kg IP) blocked these behavioral effects. Degeneration of brain 5-HT neurons by a high neurotoxic dose of PCA (2 X 10 mg/kg IP) or inhibition of tryptophan hydroxylase by p-chlorophenylalanine (300 mg/kg IP) also blocked the behavioral effects of PCA. There was a complete blockade of the PCA-induced avoidance deficit following pretreatment with metergoline, a central 5-HT receptor blocking agent. On the other hand, metergoline failed to block the hot-plate analgesia and the increased locomotion caused by PCA. Depletion of brain NA and DA by the tyrosine hydroxylase inhibitor H44/68 did not counteract the PCA effect on avoidance or hot-plate performance, but reduced the locomotor stimulating effect. The selective NA neurotoxin DSP4 (50 mg/kg IP) or the opiate antagonist naloxone (1 mg/kg) failed to affect the PCA-induced modulations of the behaviours studied. In addition, PCA administration in doses that caused avoidance deficits, did not result in motor impairment as assessed by the tread mill test. The above results support the hypothesis that the PCA-induced impairment of active avoidance acquisition does not involve changes in nociception or altered locomotor activity. It is concluded that behavioural processes related to serotonergic neurotransmission can be independently modified, suggesting differences in the underlying 5-HT mechanisms.

Amphetamines↗

PubMed1991

Motor functions in rat hindlimb muscles following neonatal sciatic nerve crush.

The sciatic nerve was crushed in the right hindlimb in newborn (3-8 h old) rats. Two to four months later, electromyographic activity was recorded from both the control and reinnervated ankle extensor muscles soleus or lateral gastrocnemius and from the ankle flexor muscle tibialis anterior. Tonic postural activity was present in the extensor muscles on both sides during quiet stance. The control flexor muscles were usually silent in this situation, but the reinnervated flexors exhibited abnormal sustained activity. During locomotion, the control extensors were activated during the stance phase and their mean burst made up 61.5% of the step cycle. The control tibialis anterior muscle fired only during the swing phase, with the burst lasting 18.1% of the step cycle. In the reinnervated extensor muscles, the mean burst duration was decreased (46% of the cycle) but the basic locomotor pattern was not impaired. The reinnervated tibialis muscle, however, was activated abnormally, with one appropriate flexor burst during the swing phase and an "extensor-like" burst during the stance phase of the step. Reflex responses to stretch were weak or absent on the operated side. Histological examination showed that the reinnervated soleus and tibialis muscles were almost devoid of muscle spindles. The motor unit mean firing rates in the reinnervated soleus (22 imp/s) and lateral gastrocnemius (45 imp/s) matched those of the control muscles (25 and 42 imp/s, respectively). In contrast to the phasic, high-frequency firing (52-80 imp/s) in the control tibialis, the reinnervated tibialis motor units fired at significantly lower rates (22-56 imp/s).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2000

Motor function and disability in the dementias.

Epidemiological and neuropathological series have identified three predominant dementing processes; Alzheimer's disease (AD), vascular dementia (VaD) and dementia associated with Lewy bodies (termed Parkinson's disease dementia (PDD) in this paper). While each has its own distinguishing features and by definition all impact upon day to day functioning, no random community derived sample has examined clinical features as defined by gait and balance abnormalities and compared disability ratings of the three dementias simultaneously. Six hundred and forty-seven community dwelling subjects participated in the Sydney Older Persons Study and of these 537 participated in a medical assessment. Of these 537,482 informants rated disability. Gait and balance abnormalities of the three major dementias were identified and the association of the dementias with disability examined. The three major dementias showed evidence of both slowing and ataxia in gait and balance tests. This was maximal in those with PDD. Similarly, all showed evidence of disability that was maximal in those with PDD. In conclusion, this study has identified that gait abnormalities are present in all three dementias to a varying degree. It is hypothesised that the varying levels of disability observed are a consequence of the varying levels of motor impairment, resulting in greater levels of disability in those with PDD.

Activities of Daily Living↗

PubMed2005

Dietary restriction alters fine motor function in rats.

A number of standard behavioral tasks in animal research utilize food rewards for positive reinforcement. In order to enhance the motivation to participate in these tasks, animals are usually placed on a restricted diet. While dietary restriction (DR) has been shown to have beneficial effects on recovery after brain injury, life span and aging processes, it might also represent a stressor. Since stress can influence a broad range of behaviors, the purpose of this study was to assess whether DR may have similar effects on skilled movement. Adult male Long-Evans rats were trained and tested in a skilled reaching task both prior to and during a mild food restriction regimen that maintained their body weights at 90-95% of baseline weight for eight days. The observations revealed that DR decreased reaching success and increased the number of attempts to grasp a single food pellet. The animals appeared to be more frantic when attempting to reach for food pellets, and the time taken to reach for 20 pellets decreased following the onset of DR. A second experiment investigating behaviors that do not require food rewards, including a ladder rung walking task and an open field test, confirmed that rats on DR display deficits in skilled movements and are hyperactive. These findings suggest that results obtained in motor tasks using food rewards need to be interpreted with caution. The findings are discussed with respect to stress associated with DR.

Animals↗

PubMed1998

High affinity Ca2+ binding sites of calmodulin are critical for the regulation of myosin Ibeta motor function.

We coexpressed myosin Ibeta heavy chain with three different calmodulin mutants in which the two Ca2+-binding sites of the two N-terminal domain (E12Q), C-terminal domain (E34Q), or all four sites (E1234Q) are mutated in order to define the importance of these Ca2+ binding sites to the regulation of myosin Ibeta. The calmodulin mutated at the two Ca2+ binding sites in N-terminal domain and C-terminal domain lost its lower affinity Ca2+ binding site and higher affinity Ca2+ binding site, respectively. We found that, based upon the change in the actin-activated ATPase activities and actin translocating activities, myosin Ibeta with E12Q calmodulin has the regulatory characteristics similar to myosin Ibeta containing wild-type calmodulin, while myosin Ibeta with E34Q or E1234Q calmodulin lose all Ca2+ regulation. While the increase in myosin Ibeta ATPase activity paralleled the dissociation of 1 mol of calmodulin from myosin Ibeta heavy chain for both wild type (above pCa 5) and E12Q calmodulin (above pCa 6), the Ca2+ level required for the inhibition of actin-translocating activity of myosin Ibeta was lower than that required for dissociation of calmodulin, suggesting that the conformational change induced by the binding of Ca2+ at the high affinity site but not the dissociation of calmodulin is critical for the inhibition of the motor activity. Our results suggest that the regulation of unconventional myosins by Ca2+ is directly mediated by the Ca2+ binding to calmodulin, and that the C-terminal pair of Ca2+-binding sites are critical for this regulation.

Actins↗

PubMedDate not supplied

[Effect of intracerebral injections of somatostatin and neurotensin on motor functions in seizure].

Experiments were performed on male Wistar rats with the aim to study effects exerted by microinjections of somatostatin and neurotensin into lateral ventricle, amygdala, hippocampus and substantia nigra pars reticulata in case of epileptic activity. It was established that the mentioned neuropeptides exerted antiepileptic effect during seizures induced by corazol and picrotoxin, which was expressed by substantial elongation of the seizure latency and a decreasing of seizure intensity. It was shown that antiseizure activity of somatostatin and neurotensin was higher under conditions of picrotoxin-induced epileptic activity, than under conditions of that induced by corazol. A conclusion is made that somatostatin and neurotensin take part in epileptic activity regulation.

Animals↗

PubMed1998

Contribution of type 1 reactions to sensory and motor function loss in borderline leprosy patients and the efficacy of treatment with prednisone.

The changes in nerve function tests in 297 new leprosy patients over an average period of 30 months were measured. The impact of type 1 reactions (T1R) on sensory and voluntary muscle function was measured by standard tests. Sensory function was improved in patients with single episodes of cutaneous T1R, but not improved in patients with neural T1R or with multiple episodes of either kind of T1R. Patients over 40 years of age improved less than younger patients, and patients admitted for treatment of T1R improved more than those treated as outpatients. These data point to a need to find better regimens for the treatment of nerve damage in T1R.

Adolescent↗

PubMed1987

GABA receptor agonists and extrapyramidal motor function: therapeutic implications for Parkinson's disease.

GABA receptor agonists display a dual action on DA-mediated events. One includes a decrease in DA release, reduction in DA receptor density, and decreased response of postsynaptic cells to dopaminergic stimulation; it results in antidopaminergic effects. The other consists of a reduction of striatal cholinergic activity resulting in a facilitation of dopaminergic effects. These two effects could be dissociated depending on the dose of GABA receptor agonists. This dual action probably explains the results of clinical trials showing either amelioration of parkinsonian symptoms with aggravation of L-DOPA-induced dyskinesia or improvement of dyskinesia without or with aggravation of parkinsonian symptoms.

Acetylcholine↗

PubMed1993

Behavioral evaluating methods in the objective clinical assessment of motor function after experimental brachial plexus reconstruction in the rat.

Unfortunately, the results of brachial plexus surgery have not fulfilled expectations. Although the components of the rat brachial plexus are similar to those of the human plexus, experimental work in this field is limited. No functional test to assess experimental brachial plexus reconstruction has so far been published. We worked out a method of evaluating brachial plexus impairment in rats in the laboratory. It consists of a simple test in which a bowl of water is projected over the animal's head, eliciting grooming movements of the forepaws towards the head. This test is therefore called the 'grooming test'. A system of scoring the animals' performance is suggested. Rats were also submitted to walking tracks analysis, but this was of limited value in assessing brachial plexus impairment.

Animals↗

PubMedDate not supplied

Sensory and motor function of teeth and dental implants: a basis for osseoperception.

1. When dental implants are loaded mechanically, a sensation, often referred to as osseoperception, is evoked. The sensory signals underlying this phenomenon are qualitatively different from the signals evoked when loading a natural tooth. In contrast with osseointegrated dental implants, natural teeth are equipped with periodontal mechanoreceptors that signal information about tooth loads. In the present review, the functional properties of human periodontal mechanoreceptors will be presented, along with a discussion about their likely functional role in the control of human jaw actions. 2. Microneurographic experiments reveal that human periodontal mechanoreceptors adapt slowly to maintained tooth loads. Populations of periodontal receptors encode information about both which teeth are loaded and the direction of forces applied to individual teeth. 3. Most receptors exhibit a markedly curved relationship between discharge rate and force amplitude, featuring the highest sensitivity to changes in tooth load at surprisingly low forces (below 1 N for anterior teeth and 4 N for posterior teeth). Accordingly, periodontal receptors efficiently encode tooth load when subjects first contact, hold and gently manipulate food by the teeth. In contrast, only a minority of receptors encodes the rapid and strong increase in force generated when biting through food. 4. It is concluded that humans use periodontal afferent signals to control jaw actions associated with intra-oral manipulation of food rather than exertion of jaw power actions. Consequently, patients who lack information from periodontal receptors show an impaired fine motor control of the mandible.

Animals↗

PubMed1983

Esophageal motility during food ingestion: a physiologic test of esophageal motor function.

It is unknown whether esophageal motility, as assessed by standard motility testing, bears close relationship to motility occurring during food ingestion. Certainly, many patients, while reporting symptoms during food ingestion, are asymptomatic during standard motility testing; thus, a direct link between abnormal motility and symptomatology is often lacking. Twelve normal subjects and 5 patients with symptomatic esophageal motility disorders, therefore, underwent motility testing during upright ingestion of a meal which consisted of beef cubes and gravy. In normals, contraction parameters during food ingestion could not have been predicted by values obtained during standard testing (r = 0.2, p greater than 0.05). All 5 patients, although asymptomatic during standard testing, reported dysphagia during food ingestion. Evidence of abnormal motility could be observed simultaneously. Patterns of abnormality included nonperistaltic contractions (7.2 +/- 2.5 episodes per meal), instances of incomplete lower esophageal sphincter relaxation (2.8 +/- 0.8 episodes per meal), and instances of lack of complete lower esophageal sphincter relaxation during ongoing esophageal contractions (4.6 +/- 1.0 episodes). These abnormalities were significantly more frequent in patients than in controls (p less than 0.001), and most had not been observed during standard testing in the patients. In addition, bethanechol significantly increased abnormal motility and increased dysphagia during food ingestion in the patients, but was without significant effect in controls. It was concluded, therefore, that recording of esophageal motility during upright food ingestion appears to be of value in the diagnosis and characterization of motor abnormalities in patients with symptoms of esophageal motor dysfunction.

Adult↗