I recently had lunch with Mark Spritzer, a Biology professor at Middlebury College. He is currently studying the effects of testosterone on working and reference memory. In one of the experiments he conducted, rats were castrated, and half of these rats then received testosterone replacement through injections. These rats then completed either a radial arm or a water maze task. A radial arm task is an octagonal-shaped structure with eight arms fanning out from each side of the center, and at the end of specific arms, foot pellets are placed. The rats must learn which arms to choose to find the food. In a water maze, rats are placed in a circular pool with a submerged platform, and these rats must explore the pool until they find the platform, and over many trials the rats learn to find the platform in a shorter amount of time. This occurs because as the rats explore their environment, they create ‘place cells’ in the hippocampus, the brain’s learning and memory center, that remember a specific location, creating a spatial map. In the study, rats that received testosterone replacement had better working and spatial memory, comparable to their non-castrated friends. The rats that were castrated but did not receive testosterone replacement had did not perform as well on the task. The most significant finding was with the radial arm task and rats with testosterone replacement: these rats found their food pellets with the fewest number of errors.
There are many implications for this research. For example, as men age, their androgen levels decrease. This can lead to age-related memory loss and Alzheimer’s. Testosterone replacement could potentially mitigate these memory loss effects. While at this point there hasn’t been a large amount of research on testosterone replacement for men, the promising results of this study could lead to large advancements in future prevention of memory loss.