Same chemical, different reaction

Drugs designed to improve memory consolidation in the elderly may also worsen working memory, according to a study by Yale researchers published in the journal Neuron in November.

The difference stems from the brain regions needed for different kinds of memory processing, according to Amy Arnsten, Ph.D., associate professor and director of graduate studies in neurobiology. The hippocampus handles long-term memory, while the prefrontal cortex is responsible for working memory. The two brain areas, Arnsten found, respond to chemicals differently.

Medications in development to improve long-term memory often try to enhance the activity of protein kinase A (PKA), an enzyme inside of cells. Arnsten and her colleagues found that when this protein was activated in the prefrontal cortex it worsened working memory.