[Excitotoxicity: theories and diseases].

Excitotoxic cell death is a direct consequence of the glutamate interaction with its receptors, through which the neuronal excitatory impulses are transmitted. Despite some well characterized aspects of this process--such as a subsequent increase in intracellular calcium concentrations and the activation of some enzymatic mechanisms--the specific intracellular pathways which mediate this cell death mechanism are still unknown. In this article, we summarize the different theories which try to explain how the neurotoxic effect development goes on beyond the glutamate receptor interaction. Apart from that, since there is a lot of evidence for the role of excitotoxicity in the aetiology and the progression of many human neurodegenerative diseases, we mention some of the experimental evidence relating certain pathologies to this form of cell death. Finally, and due the increasing necessity of more effective treatments for such diseases, we describe some anti-excitotoxic agents and its mechanisms of action.