Effects of GABA Modulator AZD7325 on Cutaneous Sensation

GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the human brain. For years, drugs that enhance its effects (e.g., benzodiazepines such as diazepam/Valium) have been used to treat various diseases such as epilepsy, insomnia, anxiety or movement disorders. However, the use of these medications is often compromised because of their side effects, such as sleepiness, memory problems, and addiction. Therefore, effort has been made to develop drugs that act more selectively in the brain to exert the positive therapeutic effects and are devoid of the unwanted side effects. AZD7325 is one of these drugs. It has been tested in more than 700 people and so far proved to be generally well tolerated. Positron emission tomography (PET) study in humans demonstrated that AZD7325 binds to GABA A receptors in the brain after a single dose. Early clinical studies have shown that it has less sedative and cognitive adverse events as compared with a benzodiazepine lorazepam. The investigators now wish to evaluate if effects of AZD7325 can be objectively measured in healthy volunteers and to establish which of the drug's outcomes could be utilised for further studies in patients with neurological diseases. The investigators are especially interested in the effects of AZD7325 on manual dexterity and skin sensation of the hand. This can be assessed by a number of simple non-invasive tests of object manipulation and detection of different sensory stimuli such as touch, vibration, or temperature. Recent studies show that healthy individuals who performed better in similar tasks had more GABA in relevant areas of their brain. If performance in these tasks in healthy volunteers can be improved by enhancing GABA effects in the brain with AZD7325, this would create the grounds for the use of this medication to treat symptoms of certain neurological disorders in which motor control and sensation of the hand is impaired (e.g., polyneuropathy).