Melatonin treatment in old mice enables a more youthful response to LPS in the brain

Melatonin modulates the expression of a number of genes related to inflammation and immunity. Declining levels of melatonin with age may thus relate to some of the changes in immune function that occur with age. mRNA expression levels in murine CNS were measured using oligonucleotide microarrays in order to determine whether a dietary melatonin supplement may modify age-related changes in the response to an inflammatory challenge. CB6F1 male mice were fed 40ppm melatonin for 9 weeks prior to sacrifice at 26.5 months of age, and compared with age-matched untreated controls and 4.5-month-old controls. A subset of both young and old animals was injected i.p. with lipopolysaccharide (LPS). After 3 hours, total RNA was extracted from whole brain (excluding brain stem and cerebellum), and individual samples were hybridized to Affymetrix Mouse 430-2.0 arrays. Data were analyzed in Dchip and GeneSpring. Melatonin treatment markedly altered the response in gene expression of older animals subjected to an LPS challenge. These changes in general, caused the response to more closely resemble that of young animals subjected to the same LPS challenge. Thus melatonin treatment effects a major shift in the response of the CNS to an inflammatory challenge, causing a transition to a more youthful mRNA expression profile

The impact of excessive alcohol use on prospective memory: A brief review

Research into the cognitive consequences of chronic excessive alcohol use continues to grow. Despite this, little research has investigated what impact excessive alcohol use might have upon everyday remembering. An important aspect of everyday remembering is prospective memory (PM), which refers to the cognitive ability of remembering to carry out an intended action at some future point in time. The majority of the studies which have focused on what impact excessive alcohol use has upon PM in teenagers and young adults have consistently found that the excessive drinkers reported more lapses in their short term (e.g., forgetting to lock one’s door upon leaving home) and long term (e.g., forgetting to post a letter on time) aspects of everyday PM, when compared to low-dose alcohol users or non-users. It is concluded from this review that PM deficits should be added to the growing list of neuropsychological sequelae associated with excessive alcohol use. The magnitude of the effects of alcohol on PM depends upon the amount of alcohol consumed and how long one has been drinking. Major limitations of these studies include their reliance upon the use of self-report measures of PM, the issue of polydrug use complicating the picture, the need to control for the co-morbidity of other conditions - such as depression, and better drug-screening methods. Therefore, further studies need to employ objective measures alongside self-report measures of PM, incorporate better controls for the use of other drugs and mood states, as well as extending the focus of the research to study what effect different patterns of alcohol use might have upon PM, e.g., what impact binge drinking has upon everyday PM. These findings have educational and applied relevance within the alcohol field