Mechanism of action of tetanospasmin is

Tetanus toxin acts presynaptically. It specifically blocks synaptic inhibition in the spinal cord, presumably at inhibitory terminals that use glycine and GABA as neurotransmitters. The abolition of spinal inhibition causes the uncontrollrd spread of impulses initiated anywhere in the central nervous system. This results in muscle rigidity and spasms. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 265