Disease relevance of High Pressure Neurological Syndrome

• The high pressure neurological syndrome in genetically epilepsy prone rats: protective effect of 2-amino-7-phosphono heptanoate [1].
• Effects of elevated pressures of inert gases on cytosolic free Ca2+ of cultured human neuroblastoma cells stimulated with carbachol: relevance to high pressure neurological syndrome [2].
• The onset pressures for the tremor, myoclonus and convulsions seen in the high pressure neurological syndrome (HPNS) are increased following cis-2,3-piperidine dicarboxylic acid 1 mmol/kg in the rat [3].

Psychiatry related information on High Pressure Neurological Syndrome

• Under these conditions, the extracellular level of dopamine monitored by differential pulse voltammetry was found to be pressure dependent, and hyperlocomotor activity, a behavioral symptom of high-pressure neurological syndrome, was found to be linked to these pressure-induced changes in dopamine release [4].
• In contrast, high pressures of helium-oxygen breathing mixtures of more than 1-2 MPa induce an increase of the striatal dopamine release and an enhancement of motor activity, referred to as the high pressure nervous syndrome (HPNS), and attributed to the effect of pressure per se [5].

High impact information on High Pressure Neurological Syndrome

• Possible NMDA antagonist properties of drugs that affect high pressure neurological syndrome [6].
• The High Pressure Neurological Syndrome (HPNS) encountered by divers breathing He/O2 mixtures at high pressures, and its known antagonism by N2, may be due in part to effects on neuronal [Ca2+]i levels since an increase in these would most likely result in an excitatory response [2].
• It is concluded that antagonism at the AMPA/kainate receptor by GYKI 52466 and LY 293558 beneficially alters HPNS signs but in a manner which is dependent on both the drug and species being studied [7].
• 5. Mephenesin, which is the most potent known drug in ameliorating HPNS, had no significant effect on the response recorded in 1 mM Mg2+ and significantly reduced the number of population spikes recorded in Mg(2+)-free medium, but this effect was only partially reversed by the addition of D-serine [6].
• 3. A derivative of benzimidazole, which shows the clearest structural similarities to known SI-glycine site antagonists and ameliorates HPNS, mirrored the effects of 7CK although it was considerably less potent [6].

Chemical compound and disease context of High Pressure Neurological Syndrome

• The effects of the competitive NMDA receptor antagonist CPP on the high pressure neurological syndrome in a primate model [8].
• Gamma-aminobutyric acid and the high pressure neurological syndrome [9].
• It is concluded that the effect of flurazepam on thresholds for the high pressure neurological syndrome is due to action at benzodiazepine receptors and not to a nonspecific effect [10].
• The effects of some biologically active metabolites of tryptophan on the high pressure neurological syndrome (HPNS) were studied [11].
• 1. The effects of a variety of structural isomers of the centrally acting muscle relaxant mephenesin on the high pressure neurological syndrome have been investigated [12].

Biological context of High Pressure Neurological Syndrome

• The elevated atmospheric pressure at which the main features of the high pressure neurological syndrome (HPNS), i.e. tremor, myoclonus and convulsions, successively appear, have been studied in fed and fasted rats with and without pretreatment with 2-amino-7-phosphonoheptanoic acid (180 mg/kg) [13].
• An area of Chromosome 2 contains a QTL marker for a gene affecting withdrawal from acute and chronic ethanol, nitrous oxide, and high-pressure neurological syndrome Type I clonic convulsions [14].

Anatomical context of High Pressure Neurological Syndrome

• Carbachol (10 nmol), injected into the red nucleus, did not influence the severity of the symptoms of HPNS [15].
• 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 [15].
• Studies on the role of the NMDA receptor in the substantia nigra pars reticulata and entopeduncular nucleus in the development of the high pressure neurological syndrome in rats [16].
• 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 [17].

Gene context of High Pressure Neurological Syndrome

• Our results show that these non-competitive NMDA antagonists had little effect on HPNS, in contrast to competitive NMDA antagonists, such as AP7, which are highly effective [18].
• These and earlier data with 2-amino-7-phosphonoheptanoic acid suggest that excitation at the N-methyl-D-aspartate receptor is important in HPNS tremor, and that excitation at the quisqualate receptor contributes to HPNS convulsions [3].
• Four non-competitive N-methyl-D-aspartate (NMDA) antagonists - MK-801, phencyclidine (PCP), SKF 10,047 and ketamine were tested in rats for effects on the HPNS [18].
• Use of 5-HT1A receptor antagonists may provide an interesting approach to prevention of HPNS [19].
• The results suggest the theta: alpha ratio, which is a one-parameter EEG evaluation in the frequency domain, is a valuable descriptor for the objective HPNS diagnosis [20].

Analytical, diagnostic and therapeutic context of High Pressure Neurological Syndrome

• Although the threshold for pressure-reversal of general anesthesia and expression of the high pressure neurologic syndrome (HPNS) is well above 12 atm abs in mice, the ethanol antagonism by 12 atm abs heliox could result from similar underlying excitatory effects [21].

References