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

Direct electrical stimulation of either the dorsal or ventral hippocampal formation elicits wet dog shakes and overt seizures. Destruction of dentate granule cells in the dorsal hippocampal formation does not significantly reduce the number of wet dog shakes elicited by ventral hippocampal stimulation. However, destruction of dentate granule cells in the ventral hippocampus virtually eliminates wet dog shaking elicited by dorsal hippocampal stimulation. Destruction of either dorsal or ventral dentate granule cells lowers the threshold for eliciting forelimb clonus with rearing. These results suggest that dentate granule cells in the ventral hippocampus are essential for wet dog shakes elicited by intrahippocampal stimulation. However, dentate granule cells throughout the hippocampal formation appear to play an important inhibitory role in the spread of seizure activity within the hippocampus.
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PMID:Differential effects of colchicine lesions of dentate granule cells on wet dog shakes and seizures elicited by direct hippocampal stimulation. 223 60

Using the techniques of selective breeding, mouse lines have been developed that express severe (Withdrawal Seizure Prone: WSP) or mild (Withdrawal Seizure Resistant: WSR) handling induced convulsions after cessation of chronic ethanol exposure. These lines differ at least ten-fold in severity of withdrawal after identical ethanol treatment. One feature of the genetic model is that other traits which distinguish these lines are presumably influenced by those genes determining ethanol withdrawal severity. WSP and WSR mice do not differ markedly in the metabolism of ethanol. In addition to handling induced convulsions, they also differ in other withdrawal signs: for example, WSP mice show more pronounced tremor. WSP and WSR mice do not differ in sensitivity to ethanol's hypothermic, anesthetic, or locomotor stimulant effects, nor in the magnitude of tolerance development to these responses. This suggests that sensitivity, tolerance and dependence are distinct genetic entities. WSP mice also display more severe withdrawal from diazepam, phenobarbital, and nitrous oxide than WSR mice, suggesting that some genes generally predispose mice to withdrawal from depressants. WSP mice display withdrawal handling induced convulsions after a single dose of ethanol, pentobarbital, or diazepam. The effective dose for producing drug seizures is not markedly different between WSP and WSR mice for a number of compounds with varied mechanisms of action. However, WSP mice are more sensitive than WSR mice to the effects of acute doses of convulsants to elevate handling induced convulsions. WSP mice have more binding sites in hippocampus for the N-methyl-D-aspartate antagonist MK 801. Binding of this ligand is increased during ethanol dependence in both mouse lines.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alcohol dependence and withdrawal: a genetic animal model. 224 62

Electroencephalographic (EEG) activity was continuously monitored from the hippocampus, amygdala, reticular formation and frontal cortex in freely moving Sprague-Dawley rats exposed to 91 atmospheres absolute pressure (ATA) using compression rates of 1 or 3 ATA/min. Videotape recordings were made for subsequent behavioural analysis. Tremor, myoclonic jerks and tonic extensions of the tail were observed in all animals but did not appear to correlate with epileptiform activity. Convulsions occurred between 66.5 and 91 ATA in all subjects compressed at 3 ATA/min, but in only 1 rat (at 91 ATA) in the 1 ATA/min group. Tonic-clonic motor seizures developed explosively and involved the entire body. EEG records showed continuous spiking at all sites during the generalized convulsive state. There was no evidence of differential susceptibility of the various brain regions examined to the epileptogenic effects of high pressure. The behavioural and EEG data indicate that hyperbarically induced seizures differ from the classical limbic type.
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PMID:Electroencephalographic and behavioural correlates of seizure development in rats in response to hyperbaric exposure. 229 48

Postnatal behavioral development and learning ability of operant performance were examined in spontaneously epileptic rats (SER: zi/zi, tm/tm), and the original tremorous mutant strains of rats, tremor rats (tm/tm) and zitter rats (zi/zi) and their controls. Before the eyes opened, the increase in body weight and the age of achieving the righting reflex on a surface were no significantly different between the SER and their littermates without epileptic seizures (SER-N: zi/zi, tm/+ or zi/zi, +/+), and between tremor rats and the original strain Kyo: Wistar rats. After the eyes opened, the increase in body weight, age of achieving the righting reflex in air and traction performance, and the development of rotarod performance, were delayed in SER and tremor rats in comparison with other groups of rats. The zitter rats were apparently inferior in their development of rotarod performance in comparison with the same zitter homozygous SER-N. Operant performance was more inferior in SER than in SER-N and in tremor rats than in Kyo: Wistar rats. The differences were much more marked between SER and SER-N than between tremor and Kyo: Wistar rats. Thus, homologous tm genes and the coexistence of homologous tm and zi genes have an inhibitory effect on postnatal behavioral development and learning ability.
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PMID:Delayed postnatal behavioral development in spontaneously epileptic rats and tremor rats, and poor operant performance in spontaneously epileptic rats. 230 98

A five-year-old male was admitted to the hospital with generalized seizures. Enlarged lymph nodes raised the suspicion of cat-scratch disease. The diagnosis was confirmed by a positive history of a cat bite, typical histopathologic findings in the biopsy of the lymph nodes, and a positive skin test. Brain CT scan and LP were repeatedly normal. The clinical course was remarkable for recurrent episodes of status epilepticus refractory to usual anticonvulsant therapy and prolonged encephalopathy consisting of mental confusion, hemiparesis, tremor, chorea, and vomiting. All neurologic symptoms gradually resolved within nine months, without sequelae. Cat-scratch encephalopathy should be suspected in a child presenting with status epilepticus and enlarged lymph nodes. Aggressive and prolonged anticonvulsant therapy is strongly recommended.
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PMID:Cat-scratch encephalopathy presenting as status epilepticus and lymphadenitis. 232 Apr 87

We have identified three examples of female Wistar rats exhibiting the tremor and seizures characteristic of the X-linked myelin deficiency (md) mutation, which is ordinarily seen only in males. Cytogenetic study of two of these animals has shown them to have 41 chromosomes instead of the normal 42. The missing chromosome was identified as an X chromosome by G-banding analysis. These animals thus have an XO genotype comparable to that in Turner's syndrome. Anatomically, one of the animals, which was studied in detail, showed no abnormality of the uterus, and the ovaries, although somewhat smaller than normal, were histologically indistinguishable from those in a normal female rat. No evidence of endocardial fibroelastosis was detected, nor was there any anomaly of the aorta. The myelin deficiency in the central nervous system was comparable to that in hemizygous mutant male rats. XO monosomy in the Wistar rat thus has little effect on phenotype and is more comparable to that in mice than to Turner's syndrome in man. The myelin-deficient rat is useful for studies of X-chromosome monosomy since XO females can readily be identified by the neurological syndrome characteristic of the md mutation.
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PMID:X-chromosome monosomy in the myelin-deficient rat mutant. 232 8

The sensitivity of spontaneously epileptic rats (SER), double homozygotes of zitter and tremor mutations, to external stimuli that induce seizures was studied in comparison with tremor (tm/tm) and zitter (zi/zi) rats, and with normal Kyo: Wistar and F 344/N rats. Touching their body, a blinking light (1200 lux, 1 sec interval) or a big sound (8 and 12 kHz, 95 dB) induced tonic extension only in the SER. The response frequency was 22 to 44% at 9 weeks of age and 75 to 100% at 13 weeks of age. Electric stimulus at 30 mA induced tonic-clonic convulsions in all Kyo: Wistar and F 344/N rats. At 20 mA the incidence of seizures decreased with age, from 100% at 5 weeks of age to 33% at 13 weeks of age in Kyo: Wistar rats and from 100 to 71% in F344/N rats. In SER, 10-mA stimuli induced tonic extension at 9 and 13 weeks of age, and 20 and 30 mA induced tonic convulsions, generalized or partial convulsions, and wild jumping or running episodes at 5, 9 and 13 weeks of age. At 30 mA, the incidence of convulsive seizures decreased with age in both tremor (tm/tm) and zitter (zi/zi) rats. Apparently external stimuli acted as simple triggers in the induction of tonic extension, since characteristic tonic extension is induced in the SER by each of the stimuli used in the present study, and induced convulsions closely resembled spontaneously occurring convulsions. The threshold of external stimuli in the induction of tonic extension became lower with aging in the SER, indicating that they are appropriate models for evaluating anticonvulsant drugs, as reported previously.
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PMID:Sensitivity of spontaneously epileptic rats to external stimuli that induce seizures. 236 23

Spontaneously epileptic rats (SER) are homozygous for two mutations, zitter (zi) and tremor (tm), and spontaneously exhibit both absence-like seizure and tonic convulsion. In addition, wild jumping or running episodes sometimes appear without any previous stimuli. We recorded the behaviour on a video camera and/or a vibration response apparatus to examine the behavioural characteristics. All wild jumping or running episodes appeared within 27 s after termination of tonic convulsion with a frequency of 2.1%, and the episode could be detected even in the dark by using the vibration response apparatus. A rapid increase of high motor activity around the episodes was recorded as a single peak with high amplitude by the vibration response apparatus. The wild jumping or running episode appeared in all 4 SER at 8-14 weeks of age with a variable frequency, 0-9 times in the light period and 0-6.7 times in the dark period 8 h each week. Thus, the wild jumping or running episode was found to occur not only during the light period but also during the dark period without any significant difference in frequency.
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PMID:Behavioural characteristics of wild jumping or running episodes in the double mutant spontaneously epileptic rat. 236 10

The spontaneously epileptic rat (SER), a mutant homozygous for both zitter and tremor genes, exhibits absence-like seizures and tonic convulsions without external stimulation from 7 to 8 weeks of age. Histopathological studies of the central nervous system revealed the following abnormalities. The 35-day-old SERs which exhibit body tremor, and which have never shown seizures, had marked vacuolation and hypomyelination in the brainstem and cerebellum. The vacuoles were produced by splitting of the myelin sheaths and swelling of the dendrites and were related to primary swelling of the astrocytes. The 2- to 3-month-old SERs with staggering gait and seizures showed focal axonal swelling ('torpedo') and advanced vacuolation in the granular cell layer of the cerebellum in addition to the abnormalities observed at 35 days of age. Degenerative neurons and spheroidal bodies were observed in the substantia nigra and ventral tegmental nucleus. These brain areas are known to be related to tonic convulsions in the several experimental models. The SER is believed to be a useful tool for the investigation of the relationship between the structure and function of the central nervous system in epilepsy. It is probable that the more severe changes in the cerebellum are responsible for the staggering gait.
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PMID:The spontaneously epileptic rat (SER), a zitter*tremor double mutant rat: histopathological findings in the central nervous system. 237 85

Several mouse mutations cause unstable locomotion, tremor, seizures, and a reduced lifespan because of deficient myelin formation in the central nervous system. Mutant alleles at the shiverer (shi) locus are the only ones in this series with a selective molecular defect, namely, in myelin basic proteins (MBPs), which are virtually absent in shi homozygotes and 50% reduced in heterozygotes. In the present study, backcross and intercross matings indicate recombination of 21.2 +/- 3.3% between myelin deficient, shimld, and fused phalanges, syfp, a marker near the middle of chromosome 18. Recombination of shimld with twirler (Tw), a marker near the centromere, is 45.7 +/- 4.9%. Thus, the shi locus maps near the distal end of mouse chromosome 18 and is the first available marker for this region. Given the evidence of other workers that an MBP locus maps to the same mouse chromosome, and that part of this chromosome may be syntenic with an MBP-PEPA region on human chromosome 18, it is likely that shi is in or near an MBP gene.
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PMID:Shiverer gene maps near the distal end of chromosome 18 in the house mouse. 241 73


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