Sending a Signal

Professor Jeffrey Karpen Discusses His Many Decades of Cellular Work

September 16, 2014
Jeffrey Karpen, PhD

In June 2014, Jeffrey Karpen came over from the West Coast—where he’d studied, researched and taught for nearly three decades—and joined the Touro College of Osteopathic Medicine as its Associate Chair of Basic Biomedical Sciences and Associate Course Director of Physiology, in addition to conducting classes as a Professor of Physiology. His full-time transition to teaching and administration comes on the heels of countless papers and publications dedicated to better understanding and exploiting cell signaling, i.e. how our cells process and interact with their environment—or, at times, fail to—and dictate our basic sensory and biological function.

It’s an incredibly complex but essential subject, one that’s taken Karpen from the academic tutelage of Stanford University’s School of Medicine to his own, authored work with the University of Colorado Health Sciences Center, Oregon Health & Science University and California Northstate University College of Medicine. But upon his arrival at Touro, Karpen’s focus had shifted primarily toward passing on his expertise and passion to students and future researchers, rather than necessarily continuing his own independent investigation of cell-signaling insight and technology. Amid the Fall 2014 semester’s early days, he took a few minutes to reflect on his winding journey and enthusiasm for helping send current students off on theirs.

For the uninitiated, how would you best explain your area of expertise?
The broad area is cellular signaling—how cells, particularly in the nervous system, receive signals from the outside world and also communicate with each other. My main interest for a long time has been second-messenger systems, which is the kind of signaling that doesn’t occur instantly. There’s cell communication that occurs very rapidly, like in neuromuscular events. I was focused on signaling events that take a little bit longer and result in longer-term changes to cells, where some signal arrives at a cell in the form of light or a hormone or a neurotransmitter or an odorant, and then a second messenger is generated inside the cell and causes cellular changes that can take from seconds to hours or even longer. The effects are more permanent, more widespread, and these systems are involved in vision, olfaction, regulation of heart rate, regulation of metabolism, learning and memory.

How did you first get drawn to this kind of research?
It’s funny how sometimes you can just hear the right thing from a potential advisor or mentor. When I got to graduate school at Cornell, I was generally fascinated by the molecular underpinnings of biological processes. My thesis advisor at Cornell gave a wonderful summary of his work where he was talking about what then were the early days of applying the principles of physical biochemistry to an understanding of the nervous system. That convergence is what led me to start studying cellular signaling.

What compelled you to move away from your research a bit and focus on teaching?
I haven’t lost any passion for research. But at the same time, through the years, I had developed a greater passion for teaching. I always took it very seriously, from my very first faculty job at the University of Colorado, but I found that my passion and interest for it grew. I decided to kind of take a career turn in 2012 and go more into the education realm and the starting of new medical schools. I feel like based on my research background and all of my teaching that I have a lot to bring to a place that’s in its early stages.

Do you still channel that initial curiosity you had as a student when motivating your current classrooms?
Yeah, absolutely. I’m trying to tell them research stories or stories about how scientists made discoveries. And I know there’s a limited amount of time we have for that, because we have to impart to them how the system works and then what can go wrong with it and how it’s treated. But I still think they get a deeper sense of everything they need to know if they see where at least some of it comes from or what was some of the thinking that went into this body of knowledge. So, yeah, I’m regularly reminded of or telling them stories from science.

What’s the most challenging question or dilemma a student has come to you with?
One thing I tried to tell the new class here, even before they started, was that the medical landscape is constantly changing. Sometimes you need to justify to students why some of their teachers [are] scientists instead of physicians (DOs or MDs). Why collect a few of us oddballs that have PhDs to teach them in the first few years? Some of it is that the standards of care we’re telling them about now or exactly what we know about a disease and how you treat it will often change within a span of 10 or 20 years. I think at that point you say your interactions with people who created knowledge in the first two years is particularly important, because you’re learning a lot of principles that won’t change. The basic mechanistic explanations for things won’t change. Because, then later, when the clinical situation changes, when new information comes out, you have a better capacity to understand that information when you read about it in the literature. I think that’s a challenge for the students, because sometimes they want to cut to, “What’s wrong in this disease and what do we do to treat it?” And that’s maybe the biggest challenge, getting them in their formative stages of understanding medicine to think about mechanisms and scientific principles, because I think that will make them stronger in the future.

With all your experience, what would be your advice to students first embarking upon their on winding journey in science and medicine?Things will change, and you have to change with them. If you see the beauty and complexity and intricacy and self-healing capabilities of the body, and if you’re always fascinated by that, it helps you get over the relentless aspects of hard work and some of the emotional difficulties of a medical career.