Effect of Experimental Litters Reduction during the Neonatal and Suckling? Periods of Ontogeny on Some Parameters of Brain Development in 30-Day-Old Rats.

We compared the effect of litter reduction on day 1 (series I) and day 14 after birth (series II) on the weight of the brain and right hemisphere and on the morphometric indicators of the development of the anteroparietal lobe in rats. Animals from both experimental series showed signs of acceleration (higher body weight and weights of the testes and ovaries). In series I, the weight of the brain and hemisphere and the thickness of the cortex surpassed the control values; the numerical density of neurons in layers II and V was lower and the numerical density of gliocytes was higher than in the control.

Dependence of Some Indicators of Brain Development in 30-Day-Old Rats on the Dynamics of Body Weight Gain in the Neonatal and Suckling Periods in Litters of Different Sizes.

We analyzed the dependence of the weight of the brain, its hemispheres, and morphometric parameters of the parietal cortex and the hippocampus in 30-day-old Wistar rats on their body weight at the age of 1, 7, 14, 21, and 30 days. All the animals were from medium-sized litters. In 6 litters (experiment), 6 rat pups were left in each litter 1 day after delivery; in 6 other litters (control), their number remained unchanged (8-13 pups).