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Effects of levetiracetam on axon excitability and synaptic transmission at the crayfish neuromuscular junction
Author(s) -
Alshuaib Shaikhah,
Mosaddeghi Julie,
Lin JenWe
Publication year - 2020
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.22154
Subject(s) - orthodromic , antidromic , neuroscience , axon , neurotransmission , inhibitory postsynaptic potential , excitatory postsynaptic potential , neuromuscular junction , crayfish , synaptic pharmacology , synapse , levetiracetam , chemistry , postsynaptic potential , motor neuron , biology , biophysics , electrophysiology , synaptic fatigue , receptor , biochemistry , epilepsy , fishery , spinal cord
Abstract Levetiracetam (LEV) is a widely prescribed antiepileptic drug, but its actions on neuronal function are not fully characterized. Since this drug is believed to enter neurons by binding to a vesicular protein during endocytosis, we used motor axons of the crayfish opener neuromuscular junction to examine potential impacts of LEV on axon excitability. Two electrode current clamp from the inhibitory axon of the opener showed that LEV reduced action potential (AP) amplitude (AP amp ) and suppressed synaptic transmission, although the latter occurred with a longer delay than the reduction in AP amp . Comparison of antidromic and orthodromic conducting APs in LEV suggested that this drug preferentially reduced excitability of the proximal axon, despite the expectation that it entered the axon at the terminals and should affect the distal branches first. Results presented here suggest that LEV modulates axonal excitability, which may in turn contribute to its antiepileptic effects.