Perspectives on cognitive domains, H3 receptor ligands and neurological disease

Histamine H-3 receptor agonists and antagonists have been evaluated in numerous in vitro and in vivo animal models to better understand how H-3 receptors modulate neurotransmitter function in the central nervous system. Likewise, behavioural models have explored the hypothesis that changes in neurotransmitter release could enhance cognitive function in human diseases. This review examines the reported effects of H-3 receptor ligands and how they influence cognitive behaviour. These data are interpreted on the basis of different cognitive domains that are relevant to neuropsychiatric diseases. Because of the diversity of H-3 receptors, their function and their influence on neurotransmitter systems, considerable promise exists for H-3 ligands to treat diseases in which aspects of learning and memory are impaired. However, because of the complexities of the histaminergic system and H-3 receptors and the lack of clinical data so far, proof of principle for use in human disease remains to be established.