Which of the following is the site of action of strychnine poison for its toxicity?
High-Yield Explanation
Strychnine competitively blocks ventral horn motor neuron postganglionic receptor sites in the spinal cord and prevents the effects of glycine, an inhibitory neurotransmitter released by postsynaptic inhibitory neurons in the spinal cord. Strychnine binds to the chloride ion channel, causing increased neuronal excitability and exaggerated reflex arcs. This results in generalized seizure-like contraction of skeletal muscles. Simultaneous contraction of opposing flexor and extensor muscles causes severe muscle injury, with rhabdomyolysis, myoglobinuria, and, in some cases, acute renal failure. Ref: Nordt S.P. (2012). Chapter 145. Strychnine. In K.R. Olson (Ed), Poisoning & Drug Overdose, 6e.