Single sodium channels, effects pyrethroids

Song JH, Narahashi T (1996) Differential effects of the pyrethroid tetramethrin on tetrodotoxin-sensitive and tetrodotoxin-resistant single sodium channels. Brain Res 712 258-264... 

Intoxication with DDT results in ataxia, loss of coordination, convulsions, and hyperexcitation of insects and mammals. Various regions of the nervous system were stimulated to discharge repetitively either in response to a single stimulus or spontaneously. These included sensory cells, synapses, and nerve fibers (2.3.36.37). Repetitive after-discharges in nerve fibers were due to an increase in the depolarizing (negative) after-potential by DDT (M, 39). Repetitive responses in neuromuscular junctions have been shown to originate in presynaptic nerve terminals (40). It appears that DDT and pyrethroids exert similar effects on the nerve membrane sodium channel (41). Detailed analyses as described below clearly show that this is actually the case. 

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