Hello guys, today in this short video we will discuss about the pathogenesis of tetanus. How tetanus toxin works? Here you can see I have drawn a neuron. Here is the motor end plate and here this small neurons are inhibitory neurons.
They are very important part of our nervous system. They are like traffic signal. They secrete inhibitory neurotransmitters like gamma-aminobutyric acid or GABA and glycine, which inhibit or stop the unnecessary stimulus.
They have special property of making sure that our nervous system functions smoothly. Tetanus toxin called tetanusplasmin is extremely potent toxin. Tetany occurs after the tetanus toxin is taken up by the neuromuscular junction or motor end plate and is transported to the central nervous system it transported from the infected locus by retrograde neural flow or blood this point is very important for exam point of view now the toxin acts on the inhibitory range of cell enter neurons and preventing the release of gaba and glycine which are inhibitor neurotransmitters as we have already discussed. This inhibition of inhibitory interneurons allows motor neurons to send a high frequency of impulse to the muscle cells which results in a sustained tetanic contraction.
Here one important thing you should remember that tetanus toxin acts presynaptically at the inhibitory neuron terminals not at the postsynaptic area. On the other hand Thank you. One condition like strychnine poisoning has a similar mechanism except that it acts postsynaptically.