Monthly Archives: January 2013

Webinar Recap: Dr. H. Craig Heller on Sleep, Circadian Rhythms, and DS Cognition

Dr. H. Craig Heller, Stanford

“I’m a mouse doctor, not a people doctor,” began Craig Heller, and from there the audience was mesmerized. Dr. Heller, co-director of Stanford’s Down Syndrome Research Center, joined us for an informative webinar focusing on sleep, circadian rhythms, and their importance to cognition. But the mouse was the star of the show — specifically, the mouse on PTZ (pentylenetetrazole).

Dr. Heller described the basic aspects of how Down syndrome affects the brain, then gave us a fascinating précis of the mouse model of Down syndrome and how it’s used in research. He sketched out the design of studies used to test the effects of GABAA antagonists on learning and memory in mice, and then detailed some of his and his colleagues’ findings on how these effects are enmeshed with the sleep/wake cycle: research shows that the improvements GABAA antagonists confer on learning ability are circadian phase-dependent.

Eye-opening stuff, to be sure — but it was his description of the effects of mouse trials of PTZ that really electrified the audience. The resulting improvement in memory and learning, which Dr. Heller has called “remarkable,” seems to extend far beyond the course of drug treatment, making PTZ what Dr. Heller calls “an excellent candidate for clinical trials,” which he says are already underway in Australia.

Summing up his line of inquiry, Dr. Heller asked, “What is it about learning and memory that’s dependent on a particular time of day?” In their ongoing efforts, he and his colleagues continue to study the intricate mechanisms of sleep to discover how they influence cognitive impairment and recovery — and how treatments might work with our brain’s natural rhythms to achieve their highest efficacy.

Did you miss the live broadcast of this presentation, which concluded with a question-and-answer session? View the recording here. Dr. Heller has graciously made his slides available; those are also available for review. You can also view other webinars in our ongoing series of expert talks — visit for this and other research updates as they occur.