Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of glutamatergic (NMDA), cholinergic and purinergic neurotransmission in the pedunculopontine nucleus, red nucleus, ventrolateral thalamic nucleus, entopeduncular nucleus, and the substantia nigra in the development of the high pressure neurological syndrome (HPNS) was investigated in the rat. Focal injection of D-2-amino-7-phosphonoheptanoate (D-APH, 5 nmol per side) into the red nucleus or the pedunculopontine nucleus was protective against HPNS-induced convulsions. Carbachol (10 nmol), injected into the red nucleus, did not influence the severity of the symptoms of HPNS. Injection of carbachol into the pedunculopontine nucleus, significantly lowered the threshold pressure for convulsions and increased the threshold pressure for tremor. 2-Chloroadenosine (5 nmol), injected into the red nucleus, produced a potent antitremorgenic effect and a similar but less pronounced effect when injected into the pedunculopontine nucleus. 2-Chloroadenosine, injected into the substantia nigra (12.5 nmol) or the ventrolateral thalamic nucleus (25 nmol), facilitated the development of tremor and, in the entopeduncular nucleus (25 nmol), facilitated the occurrence of convulsions. These results show the complexity of neurotransmitter interactions in different regions of the brain, under high pressure. They also indicate that the biochemical and anatomical substrates, involved in the convulsions produced by HPNS, differ substantially from those in other experimental models of epilepsy.
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PMID:Brain nuclei and neurotransmitters involved in the regulation of the high pressure neurological syndrome in the rat. 168 3

Genetically epilepsy prone rats (GEPR) are hypersensitive to various epileptogenic treatments and undergo characteristic generalized seizures when exposed to potent acoustic stimulation. We have studied the sensitivity of GEPR to high atmospheric pressure. Threshold pressures for behavioral symptoms of the high pressure neurological syndrome (HPNS) were recorded in normal Sprague-Dawley (SD) and GEPR (which originate from the SD strain) of both sexes. The threshold pressure (TP) for tremor and for convulsion was significantly lower in GEPR than in SD rats. The protective action of the NMDA receptor antagonist D-2-amino-7-phosphono-heptanoate (D-APH) was tested on both strains of rats. D-APH, 90 mg/kg ip was more protective against tremor in SD than in GEPR. Female GEPR were not protected against tremor. Protection against clonic seizures was similar in both sexes of GEPR and female SD rats while SD males were not significantly protected. None of the animals treated with D-APH developed the tonic phase of seizures. Blockade of the NMDA receptor with D-APH brought the threshold for convulsions in GEPR to a similar pressure to that obtained in SD vehicle-injected controls. This findings suggests the involvement of the excitatory amino acid system in the hypersensitivity of GEPR to high atmospheric pressure.
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PMID:The high pressure neurological syndrome in genetically epilepsy prone rats: protective effect of 2-amino-7-phosphono heptanoate. 202 31

We report the effect of focal injections of N-methyl-D-aspartate (NMDA, 5 nmol) and 2-amino-7-phosphonoheptanoate (APH, 5 and 10 nmol) into the ventrolateral thalamic nucleus on behavioural symptoms of the high pressure neurological syndrome in rats. The injection of NMDA significantly lowers the threshold pressure for tremor and increases its intensity. The injection of APH significantly increases the threshold pressure for tremor and decreases its intensity. APH, 10 nmol, significantly increases the threshold pressure for myoclonus and convulsions. These protective effects are, however, less pronounced than those produced by either systemic injection of APH or its focal infusion into the basal ganglia output system.
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PMID:Effect of NMDA and 2-amino-7-phosphonoheptanoate focal injection into the ventrolateral thalamic nucleus on the high pressure neurological syndrome in the rat. 215 22

Excitatory amino acid neurotransmission may be involved in the tremor component of the high pressure neurological syndrome (HPNS). 2-Amino-7-phosphonoheptanoic acid (2-APH) is a novel antagonist of excitatory amino acids with preferential activity at the N-methyl-D-aspartate receptor. Rats were injected either i.p. or intracerebroventricularly with 2-APH and subsequently exposed to pressure. The EEG changes that occur after treatment with 2-APH at 1 ATA, namely, a marked increase in delta waves (1-4 Hz) in the centro-occipital region, continue at pressure. However, the apparent duration of action of 2-APH is shorter: the power spectra of delta waves reached its maximum value after a mean time of 37 min (SD 12) compared with 60 min (SD 5) in unpressurized rats. Behavioral results include an increase in the onset pressure for tremor--82.6 ATA (SEM 4.7) in treated rats compared with 49.4 ATA (SEM 3.4) in saline controls (P less than 0.005). It is probable that the antitremor effect and the EEG changes resulting from 2-APH are due to decreased postsynaptic activity of an excitatory neurotransmitter, and these data support the hypothesis that tremor may be central rather than peripheral in origin.
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PMID:Effect of 2-aminophosphonoheptanoic acid on the EEG of rats exposed to high pressure. 372 81