Which of the following are mechanisms of action of anticonvulsants?

The mechanism of action for anticonvulsants is diverse and plays a critical role in their ability to prevent or control seizures. Inhibiting NMDA receptors is indeed a pertinent mechanism; these receptors are involved in excitatory neurotransmission in the central nervous system. By reducing the activity of NMDA receptors, anticonvulsants can decrease excitatory neurotransmission, which helps to stabilize the neuronal membrane and reduce the likelihood of seizure activity.

While the other options may be associated with neuronal signaling, they do not specifically align with the targeted mechanisms of commonly used anticonvulsants. For example, inhibiting the actions of GABA would not be useful for anticonvulsants, as GABA is the primary inhibitory neurotransmitter and enhancing its action generally helps suppress seizures. Similarly, inactivation of sodium channels and limiting calcium channel activation are indeed mechanisms used by some anticonvulsants, but since NMDA receptor inhibition directly contributes to controlling excitatory signaling, it stands out as a crucial mechanism in the context of managing seizures.