Age-related changes in brain proDynorphin gene expression in the rat.
Dynorphin has a well-established role in feeding and gustation. Alterations in taste perception and feeding behavior are common with age. We hypothesized that proDynorphin gene expression in brain areas involved in taste and feeding declines with age. Male Sprague-Dawley rats were housed individually with ad libitum access to food and water. Brain punches of the selected regions were dissected out in groups of rats aged 4-6, 12-14 and 18-21 months. ProDynorphin mRNA (measured using a cDNA probe) decreased significantly with age in arcuate nucleus and amygdala; increased significantly with age in hippocampus; and was not significantly affected in nucleus of the solitary tract, cortex, caudate putamen or hypothalamic paraventricular nucleus. These data suggest an age-related decrease in the synthesis of dynorphin in two brain regions strongly associated with feeding behavior, and an increase in dynorphin synthesis in a brain region associated with learning and memory.
Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, USA. kotzx004@umn.edu
Catherine M
CM
Kotz
Derik
D
Weldon
Charles J
CJ
Billington
Allen S
AS
Levine
D000222:Adaptation, Physiological / Q000502:physiology; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D011498:Protein Precursors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D009927:Tissue and Organ Procurement
D004745:Enkephalins; D011498:Protein Precursors; C033660:preproenkephalin