VX enhances neuronal excitability and alters membrane properties of Rana catesbeiana sympathetic ganglion neurons.
1. The effects of VX (10 microM) were examined on sympathetic ganglion neurons from the bullfrog using intracellular recording techniques. 2. VX significantly increased the amplitude of the residual EPSP from 4.8 +/- 0.86 mV (n = 4) to 13.7 +/- 1.23 mV (n = 4). 3. VX significantly decreased the membrane potential 5.2 +/- 0.75 mV (n = 6). The input resistance and the duration of the spike afterhyperpolarization (AHP) were also reduced 69.8% and 69.6% of control, respectively. 4. VX increased neuronal excitability greater than 200% (n = 5) of control. 5. The VX-induced neuronal excitability may result from a reduction in the duration of the AHP and contribute to the CNS toxicity.
Department of Anatomy and Neurobiology, University of Vermont College of Medicine, Burlington 05405.
T J
TJ
Heppner
J F
JF
Fiekers
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D005728:Ganglia, Sympathetic / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D007424:Intracellular Fluid / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009946:Organothiophosphorus Compounds / Q000494:pharmacology*; D011892:Rana catesbeiana; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects
D002800:Cholinesterase Inhibitors; D009946:Organothiophosphorus Compounds; C009680:VX-agent