What characteristic does excitatory neurotransmitter activity contribute to?

Excitatory neurotransmitter activity is primarily associated with the stimulation of neurons and the promotion of neural communication. When excitatory neurotransmitters, such as glutamate, bind to their receptors on a postsynaptic neuron, they lead to depolarization of that neuron. This depolarization is crucial because it makes the neuron's membrane potential more positive, thus moving it closer to the threshold required to trigger an action potential.

An action potential is an all-or-nothing electrical signal that travels down the axon of a neuron and is essential for transmitting information throughout the nervous system. The increased likelihood of generating an action potential in response to excitatory neurotransmitter signaling is a foundational aspect of how neurons communicate and process information.

In contrast, decreased cellular activity, inhibition of impulse control, and enhanced relaxation are more closely associated with inhibitory neurotransmitters, which serve to decrease the likelihood of an action potential or calm neuronal activity. Thus, the characteristic that excitatory neurotransmitter activity contributes to is fundamentally the increased likelihood of an action potential occurring, facilitating active signaling within the brain and nervous system.