Effect of Light During Infancy - Research Paper Example

Effect of Light during Infancy on the Function of the Brain Introduction The effect of light on the plant kingdom is very well appreciated. Animals also need light, whether it is to hunt or escape from predator or any other activity. Light is one of the five sensory inputs for the brain. Light is perceived and transmitted as electrical impulses to the brain. Loss of this input during development or infancy may affect the development and function of the brain during adulthood. HypothesisThe functions of the brain like cognition, memory, and learning are dependent on vision as the input, further development of the brain may be affected if one is deprived of this basic input.

Therefore the hypothesis is that "Light deprivation during fetal development and infancy affects the brain function during adulthood".MethodSince this experiment cannot be performed on humans, we need to test this hypothesis in a rat model for light deprivation. There will be three sets of experiments, viz., 1. Light deprivation of the mother during fetal development (pre-natal). 2. Light deprivation after birth (postnatal) for 6 weeks. 3. Light deprivation during fetal development and after birth (both pre-natal and post-natal).

Pregnant mothers will be either reared in the dark. The pups born to these mothers will be either grown in the dark (group 3) or normal light cycle, i.e., 12 hours of light followed by 12 hours of dark (group 1) for six weeks. Alternatively, pregnant mothers will be reared in normal light and the pups born to these mothers will be reared in the dark for six weeks (group 2). All other variables like room temperature, humidity, access to food, quality of food, and water will remain constant. After six weeks, the animals will be tested for learning behavior, by a T-maze.

In a T-maze, the reward (food) can be placed at one end and the hungry rat is allowed to choose the arm several times. The number of trials it takes the animal to choose the correct arm gives a measure of its learning capability. At least 6-8 animals will be tested in each group and the number of trials recorded. These values will be compared between different groups using Student's t-test to find out if there is any statistically significant difference between the different groups.PredictionsBased on the hypothesis, it is predicted that the rats that were reared in light (controls) will do better performance on learning tasks compared to other groups (1,2 and 3).

They will take fewer trials to find out the correct arm of the T-maze where the reward is present. The rats that are reared in the dark both in pre-natal and post-natal stages of development will have the worst performance, followed by the rats that were reared in the dark during the post-natal stage of development. The rats that were dark-reared during pre-natal stages will perform better than the other two test groups. Conclusion If there is a statistically significant difference between the control and group 1, 2, or 3, we will accept the hypothesis that "Light deprivation during fetal development and infancy affect the brain function during adulthood".

If there is no difference between the control and group 1 and/or between groups 2 and 3, we will reject part of the hypothesis and conclude that light exposure of the mother has no effect on the learning behavior of pups. If there is no significant difference between group 2 and control we will assume that light deprivation during infancy (or childhood) will not have any effect on learning behavior during adulthood. If there is a difference between the control and groups 1,2 and 3, we will reject the complete hypothesis and accept the null hypothesis that "Light deprivation during fetal development and infancy will not affect the brain function during adulthood".