[Pharmacologic treatment for cognitive disorders: an update]

Today, the memory is regarded as a network of memories which is sustained by distinct interconnected neuronal pathways. These diverse neuronal pathways are differentially impaired during cerebral ageing. Consequently, according to their molecular and cellular targets, cognitive enhancing therapies will be specifically applied to some neurodegenerative diseases or to age-related cognitive disorders. During recent decades, cognition enhancers have been devised in order to facilitate or to serve as substitutes for the effects of deficient neurotransmitters, particularly acetylcholine. These pharmacological approaches have allowed the proposition of acetylcholinesterase inhibitors and muscarinic agents. At present, these targets remain in progress but research is orientated on the discovery of nicotinic agents and acetylcholine releasers. Simultaneously, intense research activity has been undertaken around the other major systems of neurotransmission and/or neuromodulation such as the glutamatergic, monoaminergic and peptidergic pathways. Although research has always given precedence to symptomatic treatments (cognition enhancers) over organic treatments (neuroprotective agents), those are the subject of intensive research activity as they could be capable of counteracting the neuronal death and decrease of synaptic plasticity that occur during neurodegenerative diseases and ageing, respectively.