Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Massive abnormalities of parvalbumin-immunoreactive cortical neurons were observed in the cerebral biopsy samples of 3 patients with Creutzfeldt-Jakob disease. Immunoreactive cells had reduced and short, often fragmented, dendrites, and large numbers of dendritic varicosities were observed. Since parvalbumin-immunoreactive neurons are the most important inhibitory cells in the cerebral cortex, the damage to these neurons may account, in part, for the impaired cortical function, and may play a role in the appearance of myoclonus and electroencephalographic patterns in patients with Creutzfeldt-Jakob disease.
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PMID:Parvalbumin-immunoreactive cortical neurons in Creutzfeldt-Jakob disease. 825 May 37

There is a distinctive pattern of hippocampal involvement in Creutzfeldt-Jakob disease (CJD) and evidence for selective vulnerability of GABAergic neurons in experimental and human prion disease. We studied hippocampus and temporal cortex from human CJD and control autopsy brains and surgical cryptogenic temporal lobe epilepsy specimens for distribution and density of parvalbumin (PV) and calbindin-D28K (Cal) -positive neurons that are subpopulations of GABAergic neurons. Pathology was evaluated semiquantitatively in 8 regions in 23 CJD brains for severity of spongiform change, astrogliosis and pathological prion protein deposition. In CJD, pathology was severe in pre-parasubiculum and temporal cortex, and little or absent in CA1-4; PV+ neurons were severely reduced or absent in all cases, whereas Cal+ neurons were largely preserved. In controls, the density of PV+ neurons was highest in pre-parasubiculum and temporal cortex, and lowest in CA1-4. In cTLE, loss of PV+ neurons was seen only in CA1-4. The diffuse and severe loss of PV+ neurons in CJD, and the topographical correlation of tissue lesioning in CJD with density of PV+ neurons in controls suggest selective vulnerability and early loss of this subset of inhibitory neurons in CJD. This might relate to characteristic CJD symptoms such as myoclonus and the distinctive EEG pattern.
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PMID:Distribution of parvalbumin-immunoreactive neurons in brain correlates with hippocampal and temporal cortical pathology in Creutzfeldt-Jakob disease. 932 55

Little is known about the pathogenetic basis of characteristic symptoms in transmissible spongiform encephalopathies (TSEs) such as myoclonus and characteristic EEG hyperactivity. We investigated the GABAergic system and its subpopulations in mice inoculated with experimental scrapie (ME7, RML, 22A strains) and Creutzfeldt-Jakob disease (CJD; Fujisaki strain), to study damage to inhibitory neurons. Since recent studies have shown electrophysiological changes in prion protein (PrP) knockout mice, we also studied mice lacking or overexpressing the PrP gene. Antibodies against glutamic acid decarboxylase (GAD), parvalbumin (PV), calbindin (CB), and calretinin (CR) were used to stain GABAergic neurons, and isolectin-B4 to stain perineuronal nets around PV+ neurons. In scrapie infected mice, cortical PV+ neurons were severely reduced while CB+ and CR+ neurons were well preserved. In CJD inoculated mice, loss of PV+ neurons was severe and occurred very early after inoculation. PrP-/- and tg20 mice showed normal appearance of PV, CB, CR, GAD+ neurons and their neuropil, and of isolectin-B4+ perineuronal nets. The early, severe and selective loss of cortical PV+ neurons in experimental scrapie and CJD suggest selective loss of PV+ GABAergic neurons as important event during disease development, possibly as one basis of excitatory symptoms in TSEs.
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PMID:Severe, early and selective loss of a subpopulation of GABAergic inhibitory neurons in experimental transmissible spongiform encephalopathies. 980 71

Mongolian gerbils are epilepsy-prone animals. In adult gerbils two major groups can be differentiated according to their seizure behavior: Highly seizure-sensitive gerbils exhibit facial and forelimb clonus or generalized tonic-clonic seizures from the first test on, while kindled-like gerbils are seizure free for the first three to six consecutive tests, later develop forelimb myoclonus, and eventually progress to generalized tonic-clonic seizures. In the hippocampus, seizure history of the individual animal is mirrored in the intensity in which GABAergic neurons are immunostained for the calcium-binding protein parvalbumin: they lose parvalbumin with increasing seizure incidence. In a first step to clarify the influence of hippocampal projection neurons on spontaneous seizure behavior and related parvalbumin expression, we induced degeneration of the CA1 pyramidal cells by transient forebrain ischemia. This results in a decreased seizure sensitivity in highly seizure-sensitive gerbils. The kindling-like process, however, is not permanently blocked by the ischemic nerve cell loss, suggesting that an intact CA1 field is not a prerequisite for the development of seizure behavior. The seizure-induced loss of parvalbumin from the ischemia-resistant interneurons recovers after ischemia. Thus, changes in parvalbumin content brought about by repeated seizures are not permanent but can rather be modulated by novel stimuli.
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PMID:Ischemia-induced degeneration of CA1 pyramidal cells decreases seizure severity in a subgroup of epileptic gerbils and affects parvalbumin immunoreactivity of CA1 interneurons. 1125 24

The pathogenesis underlying the typical findings in Creutzfeldt-Jakob disease (CJD) such as periodic EEG changes or myoclonus is not fully understood. The thalamus possesses a high density of inhibitory neurones and serves as a crucial pacemaker of rhythmic EEG activity. As inhibitory neurones expressing parvalbumin (PV) are reduced in the cerebral cortex and hippocampus in sporadic CJD (sCJD), we studied the distribution and number of PV-immunoreactive neurones in sCJD thalami in order to determine whether damage to them could account for certain clinical findings. Immuno histochemical analysis was performed on the thalami from 21 sCJD patients and five controls. The number of PV+ neurones was counted in the thalamic nuclei and compared with clinical and molecular findings. In sCJD patients, PV+ neurones were significantly reduced in the ventrolateral posterior (VLp), ventrolateral anterior (VLa), anteroventral (AV), lateral dorsal (LD), mediodorsal (MD) and reticular (Re) thalamic nuclei (P < 0.05). The VLp was especially damaged in sCJD patients with homozygosity for methionine at codon 129 and scrapie prion protein (PrP(Sc)) type 1. Patients with typical EEG changes [periodic sharp wave complexes (PSWCs)] and myoclonus had a predominant loss of PV+ cells in the reticular thalamic nucleus. In conclusion, our data support the hypothesis that the damage to PV-immunoreactive neurones determines the generation of certain typical clinical features of CJD, i.e. PSWCs associated with myoclonus.
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PMID:Clinical findings in sporadic Creutzfeldt-Jakob disease correlate with thalamic pathology. 1239 Sep 80

Infantile spasms syndrome (ISS) is a catastrophic pediatric epilepsy with motor spasms, persistent seizures, mental retardation, and in some cases, autism. One of its monogenic causes is an insertion mutation [c.304ins (GCG)(7)] on the X chromosome, expanding the first polyalanine tract of the interneuron-specific transcription factor Aristaless-related homeobox (ARX) from 16 to 23 alanine codons. Null mutation of the Arx gene impairs GABA and cholinergic interneuronal migration but results in a neonatal lethal phenotype. We developed the first viable genetic mouse model of ISS that spontaneously recapitulates salient phenotypic features of the human triplet repeat expansion mutation. Arx((GCG)10+7) ("Arx plus 7") pups display abnormal spasm-like myoclonus and other key EEG features, including multifocal spikes, electrodecremental episodes, and spontaneous seizures persisting into maturity. The neurobehavioral profile of Arx mutants was remarkable for lowered anxiety, impaired associative learning, and abnormal social interaction. Laminar decreases of Arx+ cortical interneurons and a selective reduction of calbindin-, but not parvalbumin- or calretinin-expressing interneurons in neocortical layers and hippocampus indicate that specific classes of synaptic inhibition are missing from the adult forebrain, providing a basis for the seizures and cognitive disorder. A significant reduction of calbindin-, NPY (neuropeptide Y)-expressing, and cholinergic interneurons in the mutant striatum suggest that dysinhibition within this network may contribute to the dyskinetic motor spasms. This mouse model narrows the range of critical pathogenic elements within brain inhibitory networks essential to recreate this complex neurodevelopmental syndrome.
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PMID:A triplet repeat expansion genetic mouse model of infantile spasms syndrome, Arx(GCG)10+7, with interneuronopathy, spasms in infancy, persistent seizures, and adult cognitive and behavioral impairment. 2012 36