What effect does tetanus toxin have on neurotransmission?

Tetanus toxin specifically acts by inhibiting the release of neurotransmitters that are crucial for inhibitory synaptic transmission in the central nervous system. The toxin targets synaptobrevin, a protein involved in the vesicular release of neurotransmitters. By doing so, it suppresses the release of GABA (gamma-aminobutyric acid) and glycine, both of which are major inhibitory neurotransmitters. This inhibition disrupts the normal balance of excitatory and inhibitory signals in the brain and spinal cord, leading to the characteristic symptoms of tetanus, such as muscle rigidity and spasms.

In contrast, the other options relate to neurotransmission mechanisms that tetanus toxin does not affect. While the enhancement of serotonin release, stimulation of dopamine production, and blocking norepinephrine reuptake are all important processes in neurotransmission, they are not directly influenced by the action of tetanus toxin. Thus, the inhibition of GABA and glycine release is the most accurate representation of the toxin's effects on neurotransmission.