The mechanisms of long-term potentiation were investigated in two sets of experiments. The first determined the effects of the neurosteroid allopregnanolone on long-term potentiation. Results revealed that allopregnanolone inhibits long-term potentiation primarily through its actions on the GABAA receptor. The second experiment used fluorescence microscopy to create a temporal analysis of nitric oxide synthesis in response to high-frequency stimulation and found that the concentration of nitric oxide increased at two separate time periods following the induction of long-term potentiation. These findings explain how it is possible for nitric oxide to be important for increased glutamate release during the initiation of long-term potentiation, as well as gene transcription during later stages. Future research should utilize the methods created in this study to further increase the knowledge of long-term potentiation, as well as determine the mechanisms behind abnormal nitric oxide levels found in various neurological diseases.