The principal excitatory neurotransmitter in the central nervous system is glutamate. Glutamate is involved in a variety of functions throughout the brain, including learning and memory, sensory processing, and motor control. When glutamate is released by presynaptic neurons, it binds to and activates receptors on the postsynaptic neuron, leading to depolarization of the postsynaptic membrane and an increase in the likelihood of the neuron firing an action potential.

Glutamate is synthesized from precursor molecules within the presynaptic neuron, and it is stored in synaptic vesicles until it is released in response to an action potential. Once released, glutamate can bind to several different types of receptors, including ionotropic receptors and metabotropic receptors.

Ionotropic glutamate receptors are directly coupled to ion channels and can lead to rapid changes in the postsynaptic membrane potential. These receptors include the NMDA receptor, the AMPA receptor, and the kainate receptor. Metabotropic glutamate receptors, on the other hand, are coupled to intracellular signaling pathways and can lead to slower, more sustained changes in neuronal activity.

Dysregulation of glutamate signaling has been implicated in a variety of neurological and psychiatric disorders, including epilepsy, stroke, schizophrenia, and addiction. Understanding the mechanisms underlying glutamate signaling is critical for developing treatments for these disorders and optimizing neural function.