Answer and Explanation:
Botulinum toxin (BT), popularly known as "botox", is a protein produced by the bacterium Clostridium botulinum. When administered orally in large quantities, it blocks nerve signals from the brain to the muscle, causing widespread paralysis called botulism.
However, by injecting very small amounts into a specific facial muscle, only the thrust that guides this muscle will be blocked, causing local relaxation. Thus, botulinum toxin acts as a blockade of the underlying musculature of unwanted lines.
The hypothesis of the toxin not only moved over the nerve to which it connected through the neuromuscular junction, but moved to the next medullary and central synapses could be true. However, this toxin migration was limited to the target muscle brain projection cells and could theoretically potentiate the local effect of the injection. For a direct action of BT on the Central Nervous System it would be necessary to have a blood-brain barrier failure, such as capillary phenomena through which it would enter. BT also could act on neurotransmitters, other than acetylcholine, and could induce peripheral sensitization, which will lead to peripheral and central changes.