Abstract
Age, age-related pathologies, certain psychiatric disorders, head traumas and other conditions are characterised by an impairment of cognitive functions. Cognition is a complex process involving a large number of neurotransmitters that can modulate, positively or negatively, learning and memory; therefore, their receptors may represent suitable targets to develop cognition-enhancing drugs. Among others, the α7 nicotinic cholinergic receptor and the α5 GABAA receptor are emerging as attractive targets for developing therapeutics in this field. The important role of α7 nicotinic receptors has been proven thanks to the discovery of α7-selective agonists, such as GTS-21 and AR-R17779, which has stimulated the synthesis of a large number of new compounds, some of which are in clinical trials. The observation that the classical tranquilliser benzodiazepines (agonists that potentiate GABAA receptor functions), are amnesic, while inverse agonists (that attenuate the functions of the same receptor) improve cognitive tasks, stimulated the search for modulators mainly directed toward the α5-containing GABAA receptor, which seems at present the most important GABAA receptor subtype involved in cognitive processes. This article reviews the patents on modulators of α7 nicotinic acetylcholine and GABAA receptors disclosed during the period 2000 – 2006.