Neurotransmitter systems, neuroanatomical pathology and cell death in schizophrenia: update and perspectives

Schizophrenia is a thought disorder characterized by delusional thinking which may be accompanied by hallucinations involving any sensory modality. Schizophrenia may be associated with several neurologic and psychiatric disorders. Also, it may be induced by drugs. In spite of the similarity in psychoses symptomatology, it is unknown if it involves the same underlying neurobiologic mechanisms in those cases. Schizophrenic patients exhibit not only neuroanatomical alterations, but also, distortion of several neurotransmitter systems. Nowadays, the main theories in this regard involve dopaminergic hyperfunction and glutama- tergic hypofunction. Additionally, other systems involved in the schizophrenia pathophysiology are the nitric oxide pathway as well as GABAergic, glycinergic and serotonergic systems. Fur- thermore, those systems interact with each other to modulate nervous system development and cell survival. The alterations described in this paper may be part of a single cascade of events. Research in this field should focus on the elucidation of this chain to find its limits, the initial stage that originates it, and the final stage that has therapeutic implications.