Scientists in the OHSU School of Medicine's departments of Behavioral Neuroscience and Medicine, and the OHSU Cancer Institute, in a study presented Sunday to the Society for Neuroscience in San Diego, found that word retention drops sharply after only two minutes among men undergoing testosterone deprivation therapy.

However, initial learning of the words, or encoding, was the same for testosterone-deprived and healthy men, according to the study titled "Androgen ablation impairs hippocampal-dependent verbal memory processes."

Men who have undergone testosterone deprivation "are able to encode these words well, and if I ask them immediately, they can recall them as easily as non-hormone-deprived men," said Joseph Bussiere, a graduate student in behavioral neuroscience and the study's lead author. "But after only two minutes, there's a marked drop-off. When you stretch the time between encoding and retrieval, that's where the problem lies."

In testosterone deprivation or "ablation," the testicles are surgically removed or medications are given to block the production of male hormones, principally testosterone, that can promote prostate cancer growth. This common treatment for prostate cancer wipes out most male hormones found in the body.

Bussiere and Jeri Janowsky, Ph.D., professor of behavioral neuroscience and neurology, OHSU School of Medicine, say the rapid drop in memory suggests the lack of testosterone affects the function of the hippocampus, a curved, elongated ridge in the brain that controls learning and memory. In fact, Janowsky said, similar deficits - the ability to encode information initially but forget it quickly - is seen in individuals with well-known cognitive
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Contact: Jonathan Modie
modiej@ohsu.edu
503-494-8231
Oregon Health & Science University
25-Oct-2004