Desensitization of AMPA receptors limits the amplitude of EPSPs and the excitability of motoneurons of the rat isolated spinal cord

L. Ballerini, E. Bracci, A. Nistri

    Research output: Contribution to journalArticlepeer-review

    Abstract

    Intracellular recording was used to study the effect of cyclothiazide, a selective blocker of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor desensitization, on lumbar motoneurons of the rat isolated spinal cord. Cyclothiazide (25 μM) enhanced the responses to AMPA in a tetrodotoxin-insensitive fashion, without affecting those produced by N-methyl-D-aspartate or γ-aminobutyric acid. Excitatory postsynaptic potentials (EPSPs) evoked by dorsal root stimulation were strongly potentiated in amplitude while paired-pulse depression (produced by applying pairs of pulses at 2 s interval) of the EPSP was decreased. In the presence of cyclothiazide the frequency of spontaneous synaptic events was greatly increased and network-driven bursting activity developed with eventual loss of electrical excitability. The present results suggest that pharmacological block of AMPA receptor desensitization led to strong excitation of motoneurons and indicate a physiological role of desensitization in protecting these nerve cells from overactivity.
    Original languageEnglish
    Pages (from-to)1229-1234
    Number of pages5
    JournalEuropean Journal of Neuroscience
    Volume7
    Issue number6
    DOIs
    Publication statusPublished - 1995

    Keywords

    • AMPA
    • Cyclothiazide
    • Desensitization
    • Glutamate
    • Motoneurons
    • Spinal cord

    Fingerprint

    Dive into the research topics of 'Desensitization of AMPA receptors limits the amplitude of EPSPs and the excitability of motoneurons of the rat isolated spinal cord'. Together they form a unique fingerprint.

    Cite this