Effect of Testosterone Dose on Place Learning in Adult Male Rats, Poster 50

Previous studies have found that age related-cognitive decline may be related to decreases in endogenous testosterone levels. This experiment tested the relationship between testosterone and the ability to use a place-learning... [ view full abstract ]

Previous studies have found that age related-cognitive decline may be related to decreases in endogenous testosterone levels. This experiment tested the relationship between testosterone and the ability to use a place-learning strategy to solve a spatial memory task. Use of a place-learning strategy indicates that the rat learns to use spatial cues on the walls to locate its reward. Adult male rats were divided into 4 treatment groups and given daily injections: oil, 0.125mg, 0.250mg, or 0.500mg testosterone (per rat). Rats were bilaterally castrated at the start of the experiment and given a week to recover prior to the start of testosterone injections. After one week of injections, rats were given 3 days of maze habituation prior to their behavioral training day. During behavioral training, rats were tasked with employing a place-learning strategy to solve a plus-maze and reach criterion (9/10 correct trials). The day after testing, rats were euthanized and appropriate brain sections (hippocampus, striatum, cortex) were extracted. Brain-derived neurotropic factor (BDNF) was assayed from the extracted brain sections in order to determine its potential role in testosterone’s effects on spatial memory. Preliminary results are inconclusive, but indicate that the 0.250T treatment group performs more efficiently in the maze than the other groups, suggesting that certain doses of testosterone can improve the ability to employ a place strategy.