Co-existence in DUM neurones of two GluCl channels that differ in their picrotoxin sensitivity

V. Raymond, D. B. Sattelle, B. Lapied

    Research output: Contribution to journalArticlepeer-review


    Whole cell patch-clamp electrophysiology was used to study the effects of L-glutamate on dissociated cockroach (Periplaneta americana) dorsal unpaired median (DUM) neurones. Application of L-glutamate via pressure-ejection pipette resulted in a two-component hyperpolarization, consisting of an initial transient and a second, prolonged phase. Under voltage-clamp, using isotonic chloride in the saline and intrapipette solutions, two L-glutamate-gated inward currents were characterized. Their reversal potentials were close to the equilibrium potential for chloride ions. One component was selectively activated by ibotenate and was sensitive to picrotoxin (100 μM), BIDN (10 μM) and the phenylpyrazole insecticide fipronil (10 μM), known to be potent blockers of insect GABA-gated chloride channels. The second component was insensitive to picrotoxin (100 μM) and BIDN (10 μM). These findings demonstrated, for the first time, the co-existence of two pharmacologically distinct native insect neuronal L-glutamategated chloride channels. (C) 2000 Lippincott Williams and Wilkins.
    Original languageEnglish
    Pages (from-to)2695-2701
    Number of pages6
    Issue number12
    Publication statusPublished - 21 Aug 2000


    • BIDN
    • Fipronil
    • Insect neurones
    • L-glutamate-gated chloride channels
    • Picrotoxin


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