Which neurotransmitter is known for its excitatory functions and is involved in memory?

The neurotransmitter that is known for its excitatory functions and plays a significant role in memory is glutamate. Glutamate is the most abundant excitatory neurotransmitter in the brain and is essential for synaptic plasticity, which is the ability of synapses to strengthen or weaken over time. This plasticity is a fundamental mechanism underlying learning and memory processes.

Glutamate works by binding to its receptors, such as NMDA and AMPA receptors, which facilitate the transport of ions across the neuron’s membrane, leading to depolarization and the propagation of excitatory signals. This process is critical in forming new connections between neurons, which is essential for memory formation and retrieval.

Other neurotransmitters mentioned, like dopamine and acetylcholine, have important roles in brain function, but neither is as directly associated with the excitatory function and memory facilitation that glutamate provides. Endorphins mainly function to relieve pain and induce feelings of euphoria, not primarily involved in memory or excitation. Thus, glutamate stands out as the correct answer for its crucial roles in both excitatory signaling and memory.