Assessment of the Potential Role of Tryptophan as the Precursor of Serotonin and Melatonin for the Aged Sleep-wake Cycle and Immune Function: Streptopelia Risoria as a Model

• Main Authors: Sergio D. Paredes, Carmen Barriga, Russel J. Reiter, Ana B. Rodríguez
• Format: Article
• Language: English
• Published: SAGE Publishing 2009-01-01
• Series: International Journal of Tryptophan Research
• Subjects: Neuroscience; neurology
• Online Access: http://www.la-press.com/assessment-of-the-potential-role-of-tryptophan-as-the-precursor-of-ser-a1271

In the present review we summarize the relationship between the amino acid, tryptophan, the neurotransmitter, serotonin, and the indole, melatonin, with the rhythms of sleep/wake and the immune response along with the possible connections between the alterations in these rhythms due to aging and the so-called “serotonin and melatonin deficiency state.” The decrease associated with aging of the brain and circulating levels of serotonin and melatonin seemingly contributes to the alterations of both the sleep/wake cycle and the immune response that typically accompany old age. The supplemental administration of tryptophan, e.g. the inclusion of tryptophan-enriched food in the diet, might help to remediate these age- related alterations due to its capacity of raise the serotonin and melatonin levels in the brain and blood. Herein, we also summarize a set of studies related to the potential role that tryptophan, and its derived product melatonin, may play in the restoration of the aged circadian rhythms of sleep/wake and immune response, taking the ringdove (Streptopelia risoria) as a suitable model.