The separate and combined effects of early undernutrition and environmental complexity at different ages on cerebral measures in rats

Abstract

Rats were either undernourished or fed normally during the suckling period, then at 1 and 5 months of age littermates were housed in enriched or impoverished environments for 30 days. The undernutrition caused lasting reductions in the weight and size of the cerebrum and in parameters of the hippocampus, but significant deficits were not observed in the thickness and area of the occipital cortex. Differential housing differed from early undernutrition in that its largest effects were on cortical parameters, but the effects of the two conditions did partly overlap. This meant that some nutritionally induced deficits could be modified later by manipulating environmental complexity. The cerebral response of the previously undernourished rats to differential environments was not distinguishable from that of well-fed controls on the basis of the gross anatomical changes that were measured. Furthermore, no significant differences were found between the environmental effects in young and mature rats, although the latter's response tended to be somewhat less for most parameters.

Environmental Approaches to Recovery of Function from Brain Damage: A Review of Animal Studies (1981 to 1991)

“…Enriched housing has also been shown to alter gross measures of brain morphology in noradrenaline-depleted rats 63 , in malnourished rats (e.g. 9,46,47,48) and vasopressin deficient rats of the mutant Brattleboro strain34, 35. However, other researchers using adult hemidecorticate rats 86 , prenatally X-irradiated microcephalic rats SO , noradrenaline-depleted rats 8 , 65, or malnourished rats 15 have failed to observe any influence of differential housing on gross neuroanatomy, although most of them found housing effects on behavior in brain-damaged animals or on neuroanatomical measures in intact control animals. The gross measures considered were possibly too gross to reveal subtle changes accompanying functional modifications.…”

Response threshold to aversive stimuli in stimulated early protein-malnourished rats

“…In fact, it has been reported that environmental stimulation produces changes in structural, neurochemical and functional parameters in the central nervous system of the rat (26)(27)(28)(29). It has been suggested that these effects of early protein malnutrition may be partially reversed by environmental stimulation offered during malnutrition, or later during the nutritional recovery period (26,(30)(31)(32)(33).…”

Effects of prenatal protein malnutrition on hippocampal CA1 pyramidal cells in rats of four age groups

“…Based on the labeling index and cell cycle time, they concluded that undernutrition markedly diminished the rate of dentate granule cell acquisition. Katz and Davies (1983) measured the width of the hippocampus in rats fed one-half their usual diet during the period of gestation and lactation, during lactation alone, or during lactation and the post-weaning period. They observed a significant decrease in width only in rats in which undernutrition included the period of gestation.…”