In treating muscle spasms, what is the primary action of Baclofen?

Baclofen is primarily known for its action as a muscle relaxant. It is utilized to alleviate muscle spasms caused by conditions such as multiple sclerosis or spinal cord injuries. The drug works by activating GABA-B receptors in the central nervous system, which results in the inhibition of synaptic transmission and subsequent reduction in muscle tone, effectively relaxing the muscles and decreasing spasticity.

The other options pertain to mechanisms that either do not align with Baclofen's intended use or are contrary to its pharmacological properties. While stimulating muscle contraction, increasing nerve impulses, and enhancing pain response could be relevant in different contexts of neuromuscular function or pain management, they do not accurately describe Baclofen's primary therapeutic effect. Baclofen distinctly focuses on reducing muscle spasms rather than promoting muscle activity or enhancing pain perception.