Answer & Solution
Answer: Option A
Solution:
Strychnine sulphate is a toxic alkaloid that affects the central nervous system. When strychnine is ingested or enters the body, it acts as a potent stimulant on the spinal cord and the central nervous system.
Strychnine blocks the inhibitory neurotransmitter glycine in the spinal cord, which normally suppresses nerve impulses. By blocking the inhibitory signals, strychnine allows excitatory signals to be transmitted without restraint, leading to hyperexcitability of the spinal cord.
This excessive excitation of the spinal cord results in severe muscle spasms and convulsions. The spasms primarily affect the muscles involved in controlling posture and movement, leading to rigid and jerky movements.
Therefore, the correct answer is A. Stimulation, as strychnine sulphate stimulates the spinal cord by blocking inhibitory signals and causing hyperexcitability, which manifests as muscle spasms and convulsions.