Test models and new directions in dementia research

Psychopharmacology research in the dementia field is particularly difficult because there are no effective treatments on which to base models. Much effort is devoted to attempts to replace defective brain chemical transmitters or neuropeptides, with particular emphasis on the cholinergic system. There is also interest in noradrenaline, serotonin and somatostatin deficits. New directions include the study of glutamate-related excitotoxins such as quinolinic acid as possible causative agents for cerebral degeneration in dementia. Glutamate receptor antagonists, e.g. MK-801, may have the potential to limit or slow down neurodegenerative processes. Neurotrophic factors, e.g. nerve growth factor, may also possess the ability to protect neurons from irreversible loss.