“Effects of Psilocybin and other Selective Serotonin Agonists on Hippocampal Neurogenesis”
Decline in thinking processes, in particular memory, occurs naturally with aging and is greatly accelerated in dementing illnesses like Alzheimer’s Disease(AD). Even young individuals with healthy intellects value enhancers of memory, attention and problem-solving ability. There are a host of “nootropic” or pro-cognitive agents (“smart drugs”, “brain enhancers”) touted for their ability to enhance various, but not all, cognitive processes. These include nutritional supplements (CoQ10, creatine, acetyl-L-carnitine), nicotine, caffeine, Ginkgo biloba, ergoloid mesylates (Hydergine), psychomotor stimulants (e.g. amphetamines), anti-depressants, psychedelics (psilocybin, mescaline and low doses of LSD) and many more. We are especially interested in studying potential nootropic agents that work by increasing the generation of new neurons in brain. An important breakthrough in brain sciences has been the discovery that new brain cells (neurons) continue to be born throughout life in a structure of the brain known as hippocampus (HP). The hippocampus plays a critical role in learning and memory by converting short-term memories into long-term memories and is pivotal for the encoding, consolidation and retrieval of episodic memory. Several groups of scientists have shown that hippocampal-mediated learning and memory is related to the generation of new neurons in the adult brain. In rat experiments, inhibition of neurogenesis (birth and development of new neurons) with a toxic drug (used to destroy tumors) resulted in deficits in specific forms of memory. So it was logical to predict that promotion of neurogenesis would improve some aspects of memory and cognition. The proposition that psilocybin impacts cognition and stimulates hippocampal neurogenesis is based on extensive evidence that serotonin (5-hydroxytryptamine or 5-HT) acting on specific 5-HT receptor sub-types (most likely the 5-HT2A receptor) is involved in the regulation of neurogenesis in hippocampus. The in vitro and in vivo animal data is compelling enough to explore whether psilocybin will enhance neurogensis and result in measurable improvements in learning. In this presentation the effects of a schedule of psilocybin and serotonin agonist administration on hippocampal neurogenesis will be reviewed. The relevance of these findings to enhancement of some aspects of memory and learning will be discussed.
Dr. Juan (Zeno) R. Sanchez-Ramos, M.D., Ph.D. received a B.S. Degree in Biology from the University of Chicago. After 3 years experience as a free lance artist in France, Spain and Denmark, he returned to the scholar’s life, earning a Ph.D. in Pharmacology and Physiology from the University of Chicago in 1976 and a medical degree (M.D.) from the University of Illinois in 1981. He trained in Neurology at the University of Chicago and as a Fellow in Movement Disorders at the University of Miami. Currently, he is Professor of Neurology at the University of South Florida (USF) in Tampa where he holds the Helen Ellis Endowed Chair for Parkinson’s Disease Research. Dr. Sanchez-Ramos has been a staff Neurologist at the James Haley VA Medical Center since 1996. He is also the Director of the HDSA Center of Excellence at USF, a comprehensive clinic dedicated to patients with Huntington’s Disease. He is an Investigator in the NIH Alzheimer’s Disease Research Center at the Bryd AD Institute at USF. In addition to teaching and attending patients with Movement Disorders, he directs a basic research laboratory at the Haley VA with active projects in neurodegeneration, neurotoxicology and adult stem cell biology. Dr. Sanchez-Ramos is a member of the Heffter Research Institute Scientific Advisory Panel. He has had a long-standing interest in the history of hallucinogenic drug use in different cultures as well as in their untapped potential in experimental therapeutics. Most recently he is investigating the relationship between neurogenesis in adult brain and the use of tryptaminergic drugs. He is married to Catherine O’Neill Sanchez and has three children, Zachary, Zoe and Sofia.