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Effect of Experimental Litter Reduction on Cerebellum Development in Suckling Rats
B Ya Ryzhavskii1, A V Lanshakova2, Yu B Malofey2
1Far Eastern State Medical University of the Ministry of Health of Russia, Khabarovsk, Russia. 19151943@rambler.ru.
Insights
Reducing litter size in Wistar rats post-birth enhances cerebellum development. This study reveals increased body and brain weight, with significant cerebellar growth and altered cortical layer development in pups from smaller litters.
Area of Science:
- Neuroscience
- Developmental Biology
- Comparative Physiology
Background:
- Litter size is a critical environmental factor influencing offspring development.
- Early life nutrition and competition impact neurodevelopmental trajectories.
- Understanding the effects of reduced litter size on brain morphology is crucial.
Purpose of the Study:
- To investigate the impact of reduced litter size on cerebellar morphology in neonatal Wistar rats.
- To compare cerebellar growth and cellular composition between rats from reduced and control litters.
- To identify specific developmental changes in cerebellar layers and cell populations.
Main Methods:
- Wistar rats were assigned to reduced (6 pups) or control (10-12 pups) litters on day 1 postpartum.
- Body weight, brain weight, and cerebellum weight were measured at 14 days.
- Cerebellar cortex thickness, molecular layer thickness, and external granular layer thickness were analyzed.
- Numerical densities of Purkinje cells, total cells in the external granular layer, Ki-67+ cells, and GFAP+ glial cells were quantified.
Main Results:
- Rats from reduced litters exhibited significantly greater body weight, brain weight, and cerebellum weight compared to controls.
- Cerebellar cortex thickness was also significantly increased in the reduced litter group.
- While Purkinje cell density and molecular layer thickness were unchanged, the external granular layer was thinner, suggesting accelerated maturation, with increased Ki-67+ and GFAP+ cell densities.
Conclusions:
- Reduced litter size positively impacts overall growth and cerebellar development in Wistar rats.
- Early postnatal life environment, specifically litter size, significantly influences cerebellar maturation dynamics.
- These findings highlight the plasticity of cerebellar development in response to environmental conditions during the neonatal period.
Abstract:
We studied morphological features of the cerebellum in 14-day-old Wistar rats from reduced litters (the number of pups was reduced from 10-12 to 6 on the next day after birth). The control group comprised 14-day-old animals from litters of medium size (10-12 rat pups). Rats from reduced litters had greater body weight and brain weight. The weight of the cerebellum, together with the weight of the adjacent part of the brain stem and the thickness of cerebellar cortex also significantly exceeded the corresponding parameters in control animals. The thickness of the molecular layer of the cerebellar cortex and the numerical density of Purkinje cells in these rats did not differ significantly from the control. The thickness of the external granular (neurogenic) layer of the cerebellar cortex in rats from reduced litters was smaller. This can indicate accelerated reduction of this layer that persists in rats until days 20-22 of age. Numerical density of cells in the external granular layer of control and experimental animals was similar. Numerical density Ki-67+ cells in this layer, as well as GFAP+ glial cells in the granular layer of the cerebellar cortex in rats from reduced litters significantly exceeded the corresponding parameters in control animals. The cerebellum of rats from litters reduced 1 day after birth had a number of differences in important indicators reflecting the rate of its development during the neonatal and suckling periods of ontogeny.
