The principal serotonin centres in the brain are the caudal and rostral raphe nuclei. The transmission of serotonin from both of these nuclei to all areas of the brain is thought to be increased in mania compared with a non-diseased brain.
Neurotransmitters and psychiatric disorders. In: Psychiatric disorders with a biochemical basis. Donaldson D. Carnthorn, UK: The Parthenon Publishing Group Inc, 1998: 45–55.