Glutamate (neurotransmitter)
In neuroscience, glutamate refers to the anion of glutamic acid in its role as a neurotransmitter: a chemical that nerve cells use to send signals to other cells. It is by a wide margin the most abundant excitatory neurotransmitter in the vertebrate nervous system. It is used by every major excitatory function in the vertebrate brain, accounting in total for well over 90% of the synaptic connections in the human brain. It also serves as the primary neurotransmitter for some localized brain regions, such as cerebellum granule cells.
Animal model of schizophrenia
Glutamate is the most abundant excitatory neurotransmitter in vertebrate nervous systems. Evidence for the involvement of glutamate in schizophrenia includes analogous symptoms which are produced by glutamate NMDA receptor antagonists such as phencyclidine (PCP) and ketamine. PCP is a non-competitive NMDA receptor antagonist which produces hallucinations and delusions in normal subjects. In rat models, disturbed cognition, deficits in social interaction, locomotor anomalies, and prepulse inhibition deficits are seen on acute administration of PCP. Evidence that persistent PCP use and abuse in humans results in lasting deficits beyond the period of treatment has led to the suggestion that this regime in rodents may be a more accurate model of schizophrenia than acute administration. A number of protocols for chronic PCP animal models have been developed, with different effects. The effects of some, but not all protocols can be reversed by treatment with antipsychotics. In a primate model, PCP was found to induce cognitive impairments which were reversed with clozapine.