Effect of excitatory amino acid antagonists on the high pressure neurological syndrome in rats

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. Glutamic acid diethyl ester 1–3 mmol/kg has no effect on tremor or myoclonus, but increases the convulsion pressure when 3 mmol/kg is given immediately before compression. 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.