Serotonin-dopamine interaction: Experimental evidence and therapeutic relevance [Interacci�n de la serotonina y la clopamina evidencia experimental e importancia terap�utica]

Both serotonin and dopamine neurotransmitters play a key role in modulating synaptic transmission in the central nervous system. Such serotonin-and-dopamine-mediated modulatory activity has been shown to influence a wide variety of cerebral functions both of instrumental and cognitive nature. Some brain regions strongly involved in cognition such as the prefrontal cortex, hippocampal formation, and corpus striatum, are densely innervated by serotonergic and dopaminergic afferents, proceeding from the raphe complex, and the mesocorticolimbic or nigrostriatal systems, respectively. Learning and memory are strongly modulated by the neurotransmitter activity of serotonin and dopamine; in some cases, they interact interdependently to sustain the psychobiological organization of these cognitive processes. Learning and memory depends -at least in part- on short- or long-lasting changes of synapses taking place mainly on dendritic spines, and the modulatory influence of serotonin and dopamine occurring at synaptic level may affect the codification of mnemonic information on such spines. In this sense, several experimental models of neurotransmitter activity have shown a close association between serotonin-dopamine unbalance and cytoarchitectural changes underlying learning and memory impairments. � INNN, 2009