Which receptor is blocked by Tetanus toxin?

Tetanus toxin primarily affects the nervous system by blocking neurotransmitter release at the presynaptic level, specifically targeting the GABA receptors. GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system. The toxin prevents the release of GABA, leading to unopposed excitatory signals since inhibitory control is lost. This disturbance in neurotransmitter balance causes the characteristic muscle spasms associated with tetanus.

Understanding the function of GABA receptors is crucial, as they play a significant role in dampening neuronal excitability throughout the nervous system. When Tetanus toxin inhibits the release of GABA, the inhibition of motor neurons is reduced, resulting in continuous muscle contraction or spasms known as opisthotonos and trismus.

The other options involve receptors that are not directly impacted by Tetanus toxin. For example, post-synaptic dopamine receptors are involved in different aspects of brain function, including reward and motor control; adrenergic receptors are related to the sympathetic nervous system and response to stress; and histamine receptors are primarily involved in immune and inflammatory responses. These receptors do not play a role in the mechanism of action for Tetanus toxin, which specifically affects presynaptic G