Alpha- and beta-adrenergic receptor function in the brain during senescence.

Alpha- and beta-adrenergic receptors and their second messengers play an important role in brain neurotransmission. Changes in receptor function with age may be involved in the age-related changes in arousal, mood and memory. The predominance of data indicates there is decreased beta-adrenergic receptors in all areas of the brain with the exception of the cortex. Evidence suggests a decreased rate of receptor synthesis may be contributing to this loss of receptors with age. Alpha-adrenergic receptor synthesis is also diminished with age. The modulation of receptor concentrations by hormonal factors is impaired with age, especially the time to recover from receptor down-regulation.