UVM professor investigates nicotine

Dr. Paul Newhouse, professor of psychiatry at UVM’s College of Medicine and director of the Clinical Neuroscience Research Unit, is involved in three studies being performed to gain further insight into possible positive effects of nicotine on the brain. That’s right – the positive effects of nicotine on the brain. In a large, multi-center study being performed at universities such as Duke, Georgetown, and UVM, doctors are recruiting patients in their 60’s to 80’s to determine the effects that nicotine has on the brains of patients with a sort of pre-Alzheimer’s condition, known as MCI (Mild Cognitive Impairment). The study, which measures patients’ memory and attention performances, is being funded by the National Institute on Aging. In a second nicotine-related study that Dr. Newhouse is involved in, patients with a condition known as ADHD (Attention Deficit, Hyperactivity Disorder) are recruited to determine the effects of nicotine on the brains of patients with their condition. This study revalidates published research completed by Dr. Newhouse a year and a half ago, which found that nicotine was capable of improving a cognitive deficit that individuals with ADHD have. The study also compares nicotine with a nicotine antagonist – a drug that blocks the receptors that nicotine targets. Dr. Newhouse commented, “We think that we have sort of stumbled upon this mechanism.” The mechanism, as he explains, is one of inhibition which may be underactive in patients with ADHD. Individuals with ADHD can have more of an inability to inhibit certain actions than those without the disorder. According to Dr. Newhouse, the data analyses has just been finished, and currently, the effects of nicotine on motor system performance – how well an individual can perform a given motor task – are being examined, along with the effects of nicotine on what is called “delay of version.” Delay of version is the length of time a person is able to wait for something. In patients with ADHD, Dr. Newhouse thinks that their inability to wait for things is reflective of a specific cognitive deficit that nicotine may improve, acting as a stimulant similar to Ritalin. In a translational project, one that occurs across different areas of medicine, Dr. Newhouse works with a researcher at Dartmouth, who is looking at animal models of the inhibitory deficit. Paradigms of the deficit from Dr. Newhouse can be imported into animal labs, whereas those paradigms from the animal labs can be imported into humans. “If he can look at anatomy even more closely, he will be able to create a model of how systems may be dysfunctional in patients with ADHD,” Dr. Newhouse explained. What are the goals of the research? “There is no question that there is a lot of interest in developing drugs which interact with the nicotinic receptors in the brain.” The problem, as Dr. Newhouse explains it, is that these receptors are a hard target to work with, because many of the drugs that target these receptors can be toxic to the brain if they are present in too high of a concentration. So, “You must find an agent that is active, but not too active.” Despite the negative connotation nicotine has in the context of cigarette smoking, Newhouse explained that there is virtually no risk of creating an addiction in any of the patients. Dr. Newhouse posed this question to those who inquire into these sorts of risks: “Do you ever see kids on the street scoring nicotine patches?” Simply put, nicotine is necessary for an addiction, but it is not sufficient. Dr. Newhouse added that students are always encouraged to not only participate in ongoing studies at UVM, but also that his work in the hospital is always creating valuable opportunities for students looking to intern, and he encourages those hardworking students not to hesitate to get involved