Which neurotransmitter is primarily associated with excitatory signals in the brain?

Glutamate is the neurotransmitter primarily associated with excitatory signals in the brain. It plays a crucial role in synaptic plasticity, which is essential for learning and memory. As the most abundant excitatory neurotransmitter in the central nervous system, glutamate facilitates communication between neurons by binding to specific receptors, such as NMDA and AMPA receptors, leading to increased neuronal activity. This excitatory action is vital for various cognitive functions, including the formation of new synaptic connections, thus underscoring its importance in overall brain function.

Other neurotransmitters, such as dopamine and serotonin, have diverse roles, including modulation of mood and reward pathways, but they are not primarily classified as excitatory. Gamma-Aminobutyric Acid (GABA) is the principal inhibitory neurotransmitter, leading to a decrease in neuronal excitability. Therefore, glutamate stands out as the key player in excitatory signaling within the brain.