Benzodiazepines (BDZs) bind to the gamma sub-unit of the GABA-A receptor. Their binding causes an allosteric (structural) modification of the receptor that results in an increase in GABA A receptor activity. BDZs do not substitute for GABA, which bind at the alpha sub-unit, but increase the frequency of channel opening events which leads to an increase in chloride ion conductance and inhibition of the action potential
Free radicals, such as superoxide, hydroxyl ions and nitric oxide all contain an unpaired electron. These radicals can have a negative effect on cells causing oxidative damage that leads to cell death. Antioxidants, such as vitamin E, prevent cell damage by binding to the free radical and neutralising its unpaired electron. For example, vitamin E binds to OO· or O2· they form an intermediate structure that is converted to a-tocopherylquinone. A recent population based study of antioxidants concluded that a diet rich in foods containing vitamin E might help protect some people against Alzheimer’s disease (AD). Vitamin E in the form of supplements was not associated with a reduction in the risk of AD.