Gina R. Poe is an American neuroscientist specializing in the study of sleep and its effect on memory and learning. Her findings have shown that the absence of noradrenaline and low levels of serotonin during sleep spindles allow the brain to form new memories during REM, as well as restructure old memory circuits to allow for more learning during later waking periods. She currently works as a professor at the University of California, Los Angeles (UCLA).
Early life and education
Poe grew up in southern California and received her undergraduate degree in Human Biology at Stanford University. After graduating in 1987, Poe spent two years at the Department of Veterans Affairs studying the brain waves of pilots during high-G maneuvers.
Poe began working on her PhD in neuroscience at UCLA under the guidance of Ronald Harper. Her thesis concerned the neural mechanisms underlying sleep state in cats.
Poe completed her graduate training in 1995. She then pursued her postdoctoral work at the University of Arizona (UA), under the mentorship of Carol Barnes. Studying the importance of sleep in memory consolidation through recording the firing of neurons during familiar experiences, novel experiences, and during sleep, she concluded that circuits encoding recent memories are likely restructured during REM sleep to selectively strengthen new memories and weaken older ones. She also helped pioneer novel approaches to recording brain activity using coherent fiber optic imaging systems.
At UA, Poe collaborated with Bruce McNaughton and Jim Knierim to research the effects of weightlessness in space on hippocampal maps of the environment. In 1998, they recorded ensembles of place cells in rats using multielectrode arrays and assessed whether weightlessness disrupted the ability of place cells to create cortical maps.
Career and research
In 1998, Poe was recruited to Washington State University, joining the faculty as an assistant professor of Veterinary and Comparative Anatomy and an assistant professor of Pharmacology and Physiology. In 2001, Poe was recruited to the University of Michigan Anesthesiology Department. She became an assistant professor of Molecular and Integrative Physiology, as well as an assistant professor of anesthesiology.
While at the University of Michigan, Poe taught both graduate and undergraduate courses and served on the Sleep Research Society's board of directors. In 2016, Poe returned to UCLA to become a Full Professor in the Department of Integrative Biology and Physiology.
Poe is the principal investigator of the Poe Lab, and her research program has been focused on exploring the mechanisms by which the neural mechanisms of sleep support learning and memory. They research how neural patterns underlying learning are reactivated during sleep, to determine how sleep influences the encoding of memories. Her work has shown that sleep is critical for the synaptic-weakening component of memory consolidation, in which memories of lower importance are pruned. Her lab currently researches the importance of sleep-dependent memory consolidation in the memory effects of diseases (such as Alzheimer's disease, schizophrenia, and post traumatic stress disorder).
Study of sleep and memory consolidation
In 2005, Poe found that rapid eye movement (REM) sleep is important for complex associative learning in rats. After depriving rats of REM sleep for four hours, their improvement at a given task was delayed. Poe then examined the biological underpinnings of the observed theta peaks and troughs during REM sleep. She found that a shift in theta rhythms might occur due to potentiation of distal dendritic synapses and depotentiation of proximal dendritic synapses over learning.
Continuing to research the effects of decreased REM sleep on memory and cognitive performance, Poe assessed how rats' performance in water mazes was affected when non-REM sleep was left intact, but REM sleep was disrupted. They found that REM sleep is not essential for spatial learning, and that when REM sleep was disrupted during initial learning, reversal learning—the ability to disregard old information due to a change in the maze—was enhanced. This suggests that REM may help consolidate incompletely learned items.