A study of spontaneous and evoked activity in the rat hippocampus under helium-oxygen high pressure.
High pressures affect the physiology of the central nervous system. For a better understanding of this effect, we examined the hippocampal activity in the rat under high pressures (91 bars) of helium-oxygen. Effects of high pressure on hippocampal physiology are: an abnormally sustained 5-8 Hz pattern of spontaneous activity, followed, in some cases, by seizures; a marked decrease in the responses of CA1 pyramidal cells to stimulation of their commissural afferents; and a 50% decrease in the afterdischarge threshold. On the basis of the relatively well understood hippocampal physiology in normobaric conditions, our observations suggest that high pressures induce hypoexcitability of afferents and/or target cells.
Fagni
L
L
Soumireu-Mourat
B
B
Carlier
E
E
Hugon
M
M
D000818:Animals; D004056:Differential Threshold; D004566:Electrodes; D004569:Electroencephalography; D004827:Epilepsy / Q000209:etiology; D005071:Evoked Potentials; D006371:Helium / Q000494:pharmacology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D009043:Motor Activity; D010100:Oxygen / Q000494:pharmacology*; D011312:Pressure; D051381:Rats; D011919:Rats, Inbred Strains
D006371:Helium; D010100:Oxygen