On Friday, the Chemistry-Biology Interface (CBI) colloquium titled “Drugs and the brain” hosted Professor Solomon H. Snyder, award-winning neuroscientist and director of the Johns Hopkins University Department of Neuroscience.
Snyder began his career at Hopkins in 1966 as an assistant professor of Pharmacology. Seven years later, he was a full professor of both Pharmacology and Psychiatry, and he had discovered the existence of opioid receptors in the mammalian brain alongside graduate student Candace Pert.
“I was interested in neurotransmitters and drugs from the beginning. I still am,” Snyder said.
Opioid receptors have a high binding affinity for opiates such as morphine and methadone. Located within the central and nervous system, the attachment of an opioid compound to a receptor will result in pain reduction and feelings of euphoria.
“Why do we have opiate receptors if man was not born with opium inside of him?” Snyder asked the audience.
He went onto explain that opiate receptors do not respond solely to drugs that we abuse.
Following the discovery of opioid receptors was the identification of naturally occurring, endogenous peptides like enkephalins, dynorphins and endorphins. Current research suggests that these endogenous peptides play an important role in motivation, emotion, relationship-development and response to pain or stress.
The presence of opioid receptors can be likened to the existence of cannabinoid or nicotinic receptors, both of which are activation sites found within the human body. While cannabinoid receptors do respond to THC, they function naturally within a class of cell membrane receptors, reacting to human-produced endocannabinoids. The same is true for nicotinic receptors, which can respond to Nicotine, but also serve a crucial role in human cognition.
Together, endogenous peptides and exogenous opiates, like morphine, control sensations such as pain reduction and euphoria in the body’s opioid system. When the opioid receptors of the brain are rewarded by drugs of abuse, the endogenous opioids and their receptors are affected accordingly.
“The regularity with which a drug enters the brain determines its subsequent potency,” Snyder said.
Current research suggests that repeated exposure to drugs of abuse leads to the deregulation of the endogenous opioid system, consequently resulting in drug craving, seeking and relapse behaviors. That being said, Snyder noted that factors such as opioid receptor variance and genetic susceptibility to addiction influence these findings.
Freshman Barbara Merryman, an aspiring Public Health major, found the talk especially engaging and applicable to her studies.
“It was interesting to hear Snyder’s lecture after taking BBC this semester,” Merryman said.
BBC, also known as Foundations of Brain, Behavior and Cognition, is an introductory Physiopsychology course at Hopkins.
“It’s awesome to have people like Snyder right here on campus and a seminar series highlighting their work,” Merryman said.
Lauren Boucher, a graduate student in the Hopkins Chemistry-Biology Interface program, helps organize these CBI colloquia.
“With the internal speakers seminar we’re trying to highlight different, prominent professors from across the University,” Boucher said.
Past speakers have included Mario Amsel, a renowned structural biologist and Paul Talalay, who discovered the cancer-fighting benefits of broccoli sprouts.
“While [Snyder] is more involved in psychiatry and neuroscience, he has a pharmacological background as well, which is affiliated with both chemistry and biology,” Boucher said.
The CBI Graduate Program was founded in 2005 and is one of the few programs in the country that awards a Ph.D. in Chemical Biology. The program provides students with the opportunity to study chemistry and biology in a more interdisciplinary manner, employing both global and health-related perspectives.
“The CBI program is spread out among chemists, biologists, biophysicists and pharmacologists. It’s great to get these people that can kind of touch all the different fields and are right here at Hopkins,” Boucher said.
Eileen Hurn, a local Baltimorean, also enjoyed the colloquium.
“I always kept up with Hopkins stuff, ever since I first moved here,” Hurn said.
Hurn moved to Baltimore from St. Louis in 2004 after being transferred by her then-employer.
“I love science, I have always loved science,” Hurn said. “When the CBI Graduate program was set up, I was just fascinated. I thought, ‘that is such an amazing idea.’ So I’ve attended these CBI colloquia and each time I’ve just been blown away. Today was no exception.”
Hurn, who is now in her mid-fifties, remembers when Snyder’s discovery was first publicized. She was a college student completing her undergraduate studies at St. Louis University.
“I knew this study was going to change everything,” Hurn said. “I think that’s when I first realized how spectacular Hopkins was.”