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Analysis of the spinal excitatory action of pentylenetetrazol

, : Analysis of the spinal excitatory action of pentylenetetrazol. Journal of Pharmacology and Experimental Therapeutics 132: 245-250

The effects of pentylenetetrazol (Metrazol) were studied in 39 spinal cord experiments in unanesthetized cats. The doses employed (20 to 60 mg/kg) generally reduced the monosynaptic spike and increased polysynaptic activity. The effects of Metrazol on synaptic recovery in the 2N pathway were complex recovery was enhanced at stimulus intervals less than 200 milliseconds and decreased at longer intervals. Recovery processes of the motoneuron were not directly affected by the drug. The results suggest that Metrazol enhances synaptic recovery by a presynaptic action but that this effect is modified by stimulation of interneuronal systems which are primarily inhibitory. Metrazol enhanced recurrent inhibition. The results indicate that the drug increases the intensity and duration of evoked Renshaw cell discharges. The effect of Metrazol to stimulate inhibitory systems is discussed in relation to the cerebral versus the spinal locus of its convulsant action. All the effects of Metrazol were antagonized by appropriate doses of trimethadione.

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Accession: 030067807

PMID: 13761666

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