title: Effects of neonatal undernutrition and cold stress on behavior and biochemical brain parameters in rats.
abstract: This study was conducted to investigate the separate and combined effects of neonatal undernutrition (U) and cold stress (S) on the behavioral and cerebral development of postweaning rats. A severe U was imposed by feeding dams a low protein diet. Postweaning all pups were fed a control diet. S consisted of daily exposure to 5 degrees for 3 minutes from day 2 to 11. Behavioral data show that U animals, stressed (S) + nonstressed (NS), exhibited a significant deficit in reversal learning of T-maze at 21 days, an enhanced passive avoidance response, but no difference in active-avoidance at 35 days when compared to controls of the same age. S had no effect on behavior development. At death (110 days), the brains were dissected into five sections and assay for acetylcholinesterase (AChE) and cholinesterase (ChE) activities. Brain weights of U animals (NS + S) were significantly lower in all sections except dorsal cortex (DC). AChE and ChE activities were significantly higher in all sections (except DC) of U animals relative to controls. S resulted in lower cerebellar weight and ChE:AChE ratios in some sections. Our results suggest a delayed behavioral maturation in U animals and an association between early postweaning behavior and brain parameters in adult rehabilitated animals.
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D002802:Cholinesterases / Q000378:metabolism; D003080:Cold Temperature; D005260:Female; D007774:Lactation; D008297:Male; D009748:Nutrition Disorders / Q000503:physiopathology*; D011247:Pregnancy; D051381:Rats; D012193:Reversal Learning / Q000502:physiology; D013312:Stress, Physiological / Q000503:physiopathology*
chemical_list: D000110:Acetylcholinesterase; D002802:Cholinesterases