An excitatory neurotransmitter is a type of chemical messenger in the brain that promotes the transmission of signals between nerve cells, or neurons. When released, these neurotransmitters bind to specific receptors on the receiving neuron, leading to an increase in the likelihood that the neuron will fire an action potential. This process is essential for various brain functions, including learning and memory. One of the most well-known excitatory neurotransmitters is glutamate. It plays a crucial role in synaptic plasticity, which is the ability of synapses to strengthen or weaken over time, influencing how information is processed in the brain. Proper balance between excitatory and inhibitory neurotransmitters is vital for maintaining healthy brain function.