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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three patients of different ages with evidence of essential tremor of familial origin are reported. Pneumoencephalography demonstrated in these cases presence of hydrocephalus. The size of the cerebral ventricles was assessed by means of the index of Schiermann and Evans. No correlation was observed between the degree of changes in the ventricular system and the duration of the disease. Abnormalities moencephalograms concerned only the Evans index.
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PMID:[Pneumoencephalographic appearance of cerebral ventricles in spontaneous tremor]. 47 Nov 59

Systemic administration of drugs that augment 5-HT2 activity generally induces 'wet dog' shaking (WDS) in rats. This suggests that the naturally occurring form of WDS seen in untreated rats may also serve as a behavioral index of 5-HT2 receptor activation, during the performance of other behaviors. Indeed, spontaneously occurring WDS has previously been reported to be inversely related to male rat copulatory proficiency. In order to examine a potential central nervous system mechanism subsuming these behaviors, male rats were tested for WDS and sexual behavior after brainstem administration of the 5-HT2 agonist DOI. Male Long-Evans rats were implanted with cannulae terminating in the region of the nucleus raphe obscurus/inferior olive, through which they received injections of DOI (0.1-10 micrograms). DOI produced a dose-dependent decrease in sexual behavior and concurrent increase in WDS. Pretreatment with the 5-HT2 antagonist ritanserin effectively blocked the effects of DOI. The results suggest that WDS and copulatory behaviors are modulated by a shared brainstem substrate. It is possible that the results may be the behavioral concomitant of recently described brainstem cells, with bifurcating axons, that project to both the medial preoptic area and the cervical spinal cord.
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PMID:Concurrent wet dog shaking and inhibition of male rat copulation after ventromedial brainstem injection of the 5-HT2 agonist DOI. 150 96

Cerebellar Purkinje neurons accumulated propidium iodide, granular blue, and horseradish peroxidase conjugated to wheat germ agglutinin but not unconjugated horseradish peroxidase, bisbenzimide, or Evans blue when these compounds were infused into the lateral cerebral ventricles of awake, unrestrained rats. Accumulation of propidium iodide by Purkinje neurons of the vermis was associated with a reproducible behavioral abnormality characterized by truncal tremor, ataxia, and nystagmus. Both the accumulation of propidium iodide in Purkinje cells and the behavioral abnormality were prevented by prior intracerebroventricular administration of ouabain or colchicine, drugs that block neuronal transport processes. The ability of cerebellar Purkinje neurons to extract small and large molecules from the cerebrospinal fluid has important implications for their physiology and pathology.
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PMID:Selective extraction of small and large molecules from the cerebrospinal fluid by Purkinje neurons. 258 Mar 50

Long-Evans dams were fed either a vitamin B6-deficient or a control diet from day 13-14 of gestation and throughout lactation. A control pair-fed group was also included because of differences in food intake between vitamin B6-deficient and control ad libitum dams. The progeny of vitamin B6-deficient dams had all the classic symptoms of B6 deficiency. These included weight loss, ataxia, tremor, and epileptic seizures. Concentrations of the neurotransmitter dopamine (DA), and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), as well as D-2 dopamine receptor binding, 3,4-dihydroxyphenylalanine (DOPA) decarboxylase activity, and vitamin B6 levels were measured in the corpus striatum of progeny at 7, 14, and 18 days after birth. Striatal DA and HVA levels were significantly decreased in B6-deficient animals when compared to ad libitum or pair-fed controls. Daily injections of vitamin B6 to deprived animals from the 14th to 18th day after birth improved the abnormal movement and normalized the concentration of DA but not of HVA in corpus striatum. Striatal D-2 dopamine receptor binding using [3H]spiperone as ligand was significantly reduced in 18-day-old animals as compared to ad libitum and pair-fed controls. No significant differences were found at 14 days. The administration of vitamin B6 to deprived animals did not raise the level of D-2 receptor binding during the period of observation. Scatchard plots indicated that the differences in binding were due to changes in receptor number and not in KD. Corpus striatum DOPA decarboxylase activity with and without the addition of exogenous pyridoxal phosphate was significantly reduced in 14- and 18-day-old animals when compared to pair-fed controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of perinatal vitamin B6 deficiency on dopaminergic neurochemistry. 379 15

Pathological changes in the central nervous system in two strains of mice (BALB/c and C57BL/6) and two strains of rats (Long Evans and Sprague Dawley) as a result of trimethyltin (TMT) intoxication were compared. Both strains of mice were administered with trimethyltin chloride at a dosage of 3.0 mg TMT-Cl/kg b.w. while both strains of rats were exposed to 7.5 mg TMT-Cl/kg b.w. Animals were sacrificed at the time of development of observable neurological signs (tremor, aggression): 2 days for both strains of mice, 3 days for Long Evans (LE) rats, and 5 days for Sprague Dawley (SD) rats. It was found that there were both species and strain differences in TMT toxicity. Despite being exposed to a lower dose of TMT and for a shorter duration of time, mice showed more prominent neurological signs and hippocampal lesions than rats. Among the two strains of rats studied, LE rats were more sensitive than SD rats to TMT toxicity. The regional sensitivity of the CNS between mice and rats was also different, with mice showing most lesions in the hippocampal fascia dentata and rats showing more prominent neuronal damages in the olfactory cortices and hippocampal Ammon's horn. Our present investigation provides the first species/strain comparison on lesion development as a result of TMT intoxication.
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PMID:Species and strain comparison of acute neurotoxic effects of trimethyltin in mice and rats. 687 75

Tremors were observed in 15 Long Evans rats beginning at 10 to 12 days of age. These were followed by progressively worsening ataxia, hind limb paresis, episodes of immobility, and seizures by 5 to 14 weeks. Gross lesions were not observed at necropsy in rats euthanized and perfused at 4 to 16 weeks of age. Neurohistologic examination revealed dysmyelination in the central nervous system. Astrogliosis in the white matter with marked increase of expression of the glial fibrillary acid protein marker was accompanied by diffuse microgliosis. Scattered glial cells, interpreted to be oligodendrocytes, contained minute periodic acid-Schiff-positive cytoplasmic granules. Large mineralized periodic acid-Schiff-positive and laminated structures were observed in the cerebellar white matter, midbrain, and thalamus of rats over 6 weeks old. Neuronal degeneration and loss was evident in the cortex, hippocampus, and midbrain. Large axonal spheroids were found in the ventral and lateral funiculi of the spinal cord. An ultrastructural study of four affected rats revealed an almost complete absence of myelinated axons and normal sheaths, and degeneration and necrosis of oligodendrocytes. The Long Evans shaker rat represents a novel myelin mutant with a remarkable survival period and appears to have an autosomal recessive mode of inheritance.
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PMID:Familial dysmyelination in a Long Evans rat mutant. 856 54

Trimethyltin (TMT) produces unique pathological and behavioral changes after a single dose. In this study, TMT was used to examine the ability of a neurobehavioral screening battery (functional observational battery and motor activity) to characterize these behavioral changes in rats. The behavioral profile of TMT was obtained using these tests in male Long-Evans (LE) and Fischer 344 (F344) rats, to assess the influence of rat strain, and in LE males and females to evaluate gender-related differences. All rats were tested before dosing and again at 1, 7, 21, and 42 d after a single dose of either 0, 4, 6, or 8 mg/kg TMT-hydroxide (intravenously). In general, the characteristic syndrome of tremor, increased reactivity, and hyperactivity was observed; however, the magnitude and time course of these effects were much greater in F344 rats. Significant strain- but not gender-related differences were obtained when comparing TMT effects on different domains of neurological function. Comparisons of predosing data between male LE and F344 rats, as well as between male and female LE rats, revealed significant differences in baseline values for about half of the measures of the test battery. These preexisting differences, however, could not account for the observed dissimilarities in treatment effects. Quantitative and qualitative differences were evident to a greater extent when comparing LEs and F344s than between males and females. Therefore, conclusions based on these types of neurobehavioral screening data would be influenced considerably more by the differences between rat strains.
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PMID:Rat strain- and gender-related differences in neurobehavioral screening: acute trimethyltin neurotoxicity. 861 24

A distinct high-voltage rhythmic spike (HVRS) discharge characterized by a barrage of negative spikes oscillating at 5-12 Hz was observed in chronically implanted Long Evans rats. Spontaneous HVRS discharges were exhibited in 90% of 40 Long Evans rats and occurred during sudden arrest of ongoing behavior (immobility) with occasional facial/whisker twitching. However, the function of HVRS discharges in Long Evans rats remains inconclusive to date and has been associated with alpha tremor/mu rhythm, attentive mu wave, and absence seizure. To elucidate the function of HVRS discharges in Long Evans rats, several experiments were performed. In a 6-h recording session (12:00-18:00), HVRS activities primarily occurred in several specific vigilance states, being particularly abundant in a short-lasting period before vigilance changes. Several characteristics, such as durations, oscillatory frequencies, and interspike intervals (ISIs) of HVRS discharges, were altered during wake-sleep states. Oscillatory frequencies were negatively correlated with durations of HVRS segments. In addition, ISIs of a HVRS episode exhibited a crescendo-decrescendo pattern. These variable ISIs could explain why a negative correlation was found between oscillatory frequencies and durations of HVRS episodes. Moreover, HVRS discharges were demonstrated to have widespread and near-synchronous distribution to bilateral cortical areas. In addition, innocuous electrical stimuli were unable to stop ongoing HVRS discharges. By contrast, noxious stimuli elicited behavioral arousal and immediately terminated most HVRS discharges. Cortical-evoked potentials in response to mild electrical stimulation under HVRS discharges were different from those under waking state but resemble those under slow-wave sleep with a smaller magnitude. Moreover, the temporal and spectral characteristics of spontaneous HVRS activities were analogous to those of seizure activities induced by penicillin and pentylenetetrazol. The incidence of spontaneous HVRS discharges was significantly decreased by ethosuximide administration. Based on these results, HVRS discharge might not be associated with a voluntary mu-rhythm behavior, instead it behaves as an absence-like seizure activity. These results were also collaborated using other genetic absence-seizure rats, such as WAG/Rij and GAERS rats. Possible mechanisms for the generation and termination of paroxysmal HVRS discharges are also discussed.
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PMID:Is spontaneous high-voltage rhythmic spike discharge in Long Evans rats an absence-like seizure activity? 1282 56

We attempted to cryopreserve spermatozoa from closed colonies (Jcl:SD and Jcl:Wistar), and inbred (BN/Crj, F3441 DuCrj, LEW/Crj, Long-Evans and WKY/NCrj), mutant (Zitter [WTC.ZI-zi] and Tremor [TRM]), transgenic (human A-transferase [A], and green fluorescent protein [GFP]) strains of rats. Rat epididymal spermatozoa suspended in cryopreservation solution (23% egg yolk, 8% lactose monohydrate, and 0.7% Equex Stm, pH 7.4, adjusted with 10% Tris [hydroxymethy] aminomethane) were frozen and stored at -196 degrees C. After thawing at 37 degrees C, the spermatozoa were instilled into the tip of each uterine horn of the recipients. A total of five recipient females for each strain were inseminated with cryopreserved spermatozoa, and normal live offspring of all strains (Jcl:SD: 11, Jcl:Wistar: 13, BN/Crj: 9, F344/DuCrj: 28, LEW/Crj: 4, Long-Evans: 6, WKY/NCrj: 8, TRM: 24, WTC.ZI-zi: 27, A: 30 and GFP: 20) were obtained.
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PMID:Cryopreservation of spermatozoa from closed colonies, and inbred, spontaneous mutant, and transgenic strains of rats. 1472 12

A variety of tests have been developed to study neurotoxicant-related changes in motor function. However, despite recent advances, there remains a need for simple and specific tests of fine motor movements. Accordingly, we chose to evaluate whether a method developed for measuring changes in skilled movements following motor pathway lesions in rodents would provide a sensitive, specific, and economical approach to assessing fine motor control in the toxicology laboratory. We measured skilled paw reaching using the "staircase test" developed by Montoya et al. [Prog. Brain Res. 82 (1990) 459], in which a rat retrieves food pellets by reaching down from a central platform to a series of descending steps on either side, grasping the pellets in its forepaw, and lifting them to its mouth. Staircase boxes were scaled for the body weights of young adult male (350 g) and female (250 g) Long-Evans rats. Studies were conducted using harmaline, a tremorigen; scopolamine; methyl scopolamine; and 2,4-dithiobiuret (DTB), a compound that causes muscle weakness by interfering with cholinergic transmission at the neuromuscular junction. Harmaline (0, 1.0, 3.0, and 10.0 mg/kg) reduced pellet retrieval only at a dose that also caused visible tremor. Both scopolamine (0, 0.1, 0.3, and 1.0 mg/kg) and methyl scopolamine (0, 0.104, 0.312, and 1.04 mg/kg) impaired pellet retrieval; scopolamine was more effective than methyl scopolamine. DTB (5 daily doses of 0, 0.1, 0.2, and 0.5 mg/kg) had no effect on retrieval, even when causing visible signs of weakness. These data cast doubt on the utility of this method for detecting and quantifying subtle chemical-induced changes in motor function in rats.
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PMID:Toxicological evaluation of the staircase test for assessing fine motor movements. 1500 Dec 20


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