King Arthur
March 8, 2022
Assignment 2b: Essay Outline Assignment
March 8, 2022
Introduction
Sleep deprivation has become a constant feature of contemporary life. Sleep deprivation has been shown to cause high blood pressure, diabetes, heart attack, stroke, depression, obesity and immunosuppression. Notably, sleep deprivation is more common in women due to various hormonal and physiological factors that make it difficult for them to get to sleep consistently. This is even worse for pregnant women, who have to sleep for two – themselves and the growing foetus inside them. Various studies have been done to demonstrate the effect that sleep deprivation has on the mother, the growing foetus and the newborn baby. Therefore, this paper will provide a brief review of a study on the effects of sleep deprivation done by Peng and colleagues.
Article overview
The study conducted by Peng and colleagues (Peng, et al., 2016) focused on the effects of sleep deprivation at different stages of pregnancy on the brain development of the offspring. Due to ethical considerations, the study made use of pregnant rats and their offspring and sought to find out whether sleep deprivation, during different stages of their 21-day gestation, impaired emotional and cognitive functions. The sleep deprivation was performed through gentle handling for 6 hours per day during their first, second and third trimester. The emotional and cognitive functions of the offspring were tested after days 42-56 post-partum. The hippocampal long term potentiation was also tested.
A battery of tests was conducted to find out the sought out effects. These included cognitive tests such as the Morris water maze, the elevated plus-maze test, the novelty-suppressed feeding test, the forced swimming test, electrophysiology in vivo and in vitro.
Findings obtained from these tests showed that sleep deprivation in the mother impaired the spatial learning and memory of the offspring rats. This was demonstrated through the offspring rats taking longer to find the hidden platform in the Morris water maze. Additionally, maternal sleep deprivation increased anxiety and depression in offspring rats and this was demonstrated by the short-latency to immobility observed in the offspring during the forced swimming tests. The offspring rats also showed increased anxiety in the novelty-suppressed feeding tests where there was an increase in the latency to feeding and the amount of food consumed was reduced. Maternal sleep deprivation also reduced adult hippocampal neurogenesis and impaired hippocampal long term potentiation. This was demonstrated by the reduced number of neuronal phenotypes seen via electrophysiology. Therefore, maternal sleep deprivation resulted in the number of new neurons in the hippocampal formation.
Through these findings, the researchers concluded that maternal sleep deprivation at different stages of pregnancy led to a drastic increase in depression and anxiety in offspring. Furthermore, it also drastically affected the spatial learning and memory abilities of the offspring. These manifestations correspond with the impairments in long term potentiation and synaptic transmission in the hippocampus of the offspring rats.
Novelty of results
These results stand out from the rest of the studies done on maternal sleep deprivation in a few ways. First, this study provides the effects of sleep deprivation during different stages of gestation. Many studies before that had only focused on the impact of maternal sleep deprivation on the last trimester of gestation (Gulia, Patel, & Kumar, 2015). This puts into perspective the idea that sleep deprivation during any stage of gestation could have adverse effects on the growing foetus. Extrapolating this data to humans shows the significant impact that maternal sleep deprivation may have on the growth of a human foetus.
Secondly, the study provides a unique insight into the effect of maternal sleep deprivation on the growing and grown hippocampus. Studies conducted before this had focused on the hormonal discrepancies that arise in the offspring from maternal sleep deprivation (Pardo, et al., 2016). Through in-vivo and in-vitro electrophysiology, the researchers were able to show the impact maternal sleep deprivation has on the long-term potentiation of the hippocampus.
Outstanding questions
Despite, the novelty of the findings in the study, several fundamental questions need to be asked. First, the obvious downside that exists in using an animal model is the credibility of the results when extrapolated in human beings. Therefore, is it logical to extrapolate these results in human models? The results point towards the potential effects of maternal sleep deprivation in humans, however, that does not hold much weight. Thus, this leaves a gap in the research on maternal sleep deprivation.
Additionally, an important question would be whether the effects of maternal sleep deprivation can be reversed over time. The human brain is more complex than the rat brain, and it is subsequently more plastic (Mateos-Aparicio & Rodríguez-Moreno, 2019). Therefore, hypothetically, some of the effects of maternal sleep deprivation can be corrected over time to give healthy human adults. This has not been explored in the study and it leaves room for further research.
Conclusion
In conclusion, the study provides insight into the negative effects of maternal sleep deprivation in the emotional, mental and physiological development of the hippocampus. However, further studies can be done to determine the magnitude of these effects on human models and also find out whether these effects can be reversed through neuroscience.
References
Gulia, K. K., Patel, N., & Kumar, V. M. (2015). Increased ultrasonic vocalizations and risk-taking in rat pups of sleep-deprived dams. Physiology and Behaviour, 59-66.
Mateos-Aparicio, P., & Rodríguez-Moreno, A. (2019). The Impact of Studying Brain Plasticity. Frontiers in Cellular Neuroscience. doi:https://doi.org/10.3389/fncel.2019.00066
Pardo, G. V., Goularte, J. F., Hoefel, A. L., Castro, A. L., Carlos, L., Araujo, A. S., & Lucion, A. B. (2016). Effects of sleep restriction during pregnancy on the mother and fetuses in rats. Physiology and Behavior, 155, 66-76.
Peng, Y., Wang, W., Tan, T., He, W., Dong, Z., Wang, Y. T., & Han, H. (2016). Maternal sleep deprivation at different stages of pregnancy impairs the emotional and cognitive functions and suppresses hippocampal long-term potentiation in offspring rats. Molecular Brain, 1-10.
