Abstract
The chronobiology community lost one of its shining lights when Tim Bartness died on September 24, 2015, in Atlanta, Georgia, from complications of multiple myeloma. He was 62 years old.
Over the course of 3 decades, Tim was a major contributor to our understanding of the neuroendocrine basis of mammalian seasonality, through a string of insightful empirical studies and influential reviews. He also is celebrated for studies of sympathetic and sensory nervous system innervation and neural control of white and brown adipose tissue, obesity reversal, and studies of foraging and hoarding, as recounted in a memorial by Grill and Levine (2015).
Tim’s friends, colleagues, and collaborators share some of their memories of Tim.
Memories of a Favorite Colleague
Eric Bittman
I first met Tim Bartness in 1982, when I visited Gainesville to interview for a job in the psychology department. I was a poor fit for the position, as evidenced by the fact that when it came time for me to give my job talk, the audience filed in late and sat as far back in the auditorium as possible. My seminar was based on my postdoctoral work on the role of melatonin in seasonality and was entitled “How Sheep Tell Time.” Characteristically, Tim relieved the gloom by injecting humor into the situation. He said, “That’s easy—they wear hamsters on their wrists!” The interview was a disaster but the bright spot was the start of our friendship.
I renewed my friendship with Tim when I moved to a faculty position at UMass Amherst. By this time, he was a postdoc in George Wade’s lab, and we started our work together on the role of the SCN in photoperiodic control of body weight and reproduction. Our collaboration continued after Tim had relocated to the Worcester Foundation to work with Bruce Goldman. Tim had participated in melatonin infusion experiments in hamsters, which are long-day breeders; these closely paralleled my postdoctoral work, which used a similar technique in sheep. Both lines of research converged upon the realization that the duration of melatonin encodes the length of the night, but we did not know where the relevant brain targets might lie. Tim and I devised a series of experiments in which we subjected Siberian hamsters, some of which were intact and others of which had received SCN lesions, to timed infusions of melatonin.
It was always a delight to work with Tim. He would start each day with his obligatory Diet Coke (required for his caffeine fix) and we would exchange banter, opinions, and all manner of stimulating conversation. He entertained me with accounts of his earlier work, such as his participation (perhaps as a subject) in studies in Minnesota on “maldigestion.” This involved use of a flatulometer, which, he assured me, was exquisitely sensitive. At about this time, Tim had submitted a long and detailed manuscript on photoperiod and body weight to Endocrinology. One reviewer was so overwhelmed that he commented that he found the manuscript so dense and complicated that he could not get through it, for the same reason that he never finished reading James Joyce’s Ulysses. From that point on, we would refer to “the Ulysses paper,” but I think Tim learned from the experience to make the written accounts of his research accessible to the reader.
We recruited Geert deVries to join our efforts to characterize the SCN and melatonin action in the hypothalamus of Siberian hamsters, and on one occasion while we were working together, Tim was overcome by an allergic reaction to the animals. In those halcyon days, it was not yet possible to follow the current literature by computer, and we would try to keep current by reading a weekly publication called Current Contents, which included the table of contents of hundreds of journals. As a colleague took him to the emergency room while Geert and I completed our perfusions, Tim’s parting words were, “Don’t forget to put Current Contents on my grave!” Fortunately, we were able to enjoy Tim’s companionship and collegiality for another 25 years after that, but we still have been deprived of it too soon.
Our interactions decreased in frequency after Tim departed for Atlanta, with the significant exception of his sponsorship of Kay Song’s thesis project in my lab. I found it gratifying to follow a logical series of steps to pursue the question of where and how melatonin acts, and to do so with such a like-minded and congenial collaborator. As the field has moved toward an understanding of the regulation of gene expression by melatonin over recent years, much work has focused on the action of this pineal hormone in the pars tuberalis of the pituitary complex. From his physiological perspective, Tim understood that many of melatonin’s important sites of action are in the brain, and he persisted in pursuing this line of work even though it was not as flashy or popular. I am confident that this emphasis will prove to be correct.
Tim and I shared many values and a perspective on science. Basic to this was the strong inference approach, described in the article of this title by J. R. Platt (1964). In that article, Platt says that many scientists who follow these habits of thought are “disputatious.” I never found this to be true of Tim. He found the exercise of devising multiple alternative hypotheses, and devising creative ways to test them, a stimulating challenge—and one that was a joy to pursue when leavened with his sharp sense of humor. He complemented these skills with the energy and leadership to recruit others to the effort. Tim was always a gentleman, kind and generous to a fault, and a great friend and colleague.
Of Hamsters and Men: A Sad Farewell to My Friend and Mentor
Gregory Demas
My intellectual and personal journey with Tim began before I arrived in the Bartness lab in the winter of 1998. I was finishing my PhD work in Baltimore and perhaps was too efficient with one manuscript, as approximately 2 months after submission, I came across this reviewer statement: “I’ve heard of people publishing the same data twice, but twice in the same manuscript is a bit much.” Hello, Tim Bartness. Apparently, in my haste to get the manuscript submitted, I accidentally pasted Figure 1 in twice. His cheeky comment was, as always, followed by 2 pages of positive comments and constructive feedback on how to improve the manuscript.
Tim Bartness in 2013.
Tim had a keen yet critical eye for data, what they meant, how to interpret them, and how best to present them. He always wanted to see the data plotted, replotted, and replotted anew, until the story revealed itself on the page. For Tim, seeing truly was believing. Tim, like most other scientists, used statistics in his research, but he put much more faith in what the data looked like. In truth, his primary statistical test was what he called the “Bartness Rapid Eye Test.” When you look at the figure, do the differences look real? Do they look meaningful? Tim had little patience for whether or not a difference was statistically significant. He only cared if it was biologically significant. I can still hear his voice as he would see a figure that had what appeared to be a marginal effect. He would exclaim, “I wonder what statistics they’re using; this doesn’t come close to passing the rapid eye test.” I’m convinced Tim was almost always right and that the findings would never be replicated. Tim taught us to question whether an effect really was meaningful. To this day all students who have trained in my lab have learned about, and employed, Tim’s “test.”
It was Tim’s work in photoperiodic regulation of body fat that drew me to his laboratory. Early on he conducted a series of important studies aimed at understanding how the pattern of the pineal hormone melatonin contributed to photoperiodic changes in physiology and behavior in Siberian hamsters. Tim, along with his mentor Bruce Goldman and collaborator Eric Bittman, made critical contributions to the study of seasonal reproduction, demonstrating an important role for the duration of melatonin secretion and its actions on the SCN and on the reproductive system. To a young graduate student like myself, his review “The Timed Infusion Paradigm for Melatonin Delivery: What Has It Taught Us about the Melatonin Signal, Its Reception, and the Photoperiodic Control of Seasonal Responses?” was a magnum opus. Not only did it have the longest journal article title I had ever encountered, but it was an elegant, thorough, and deeply insightful review of the literature. At the time the review was published, there was some controversy over which parameter of the nocturnal secretory pattern of melatonin was important for regulating seasonal changes in physiology and behavior. The article provided evidence that the duration of melatonin secretion is critical for eliciting seasonally appropriate responses in both long- and short-day breeding mammals. I recall discussing how influential that article had been in shaping my interests in biological rhythms and melatonin. With that boyish smile on his face (often on display when he was about to share a naughty little secret), Tim proudly told me that he came up with the first part of the title just so it would spell “TIP.” This, of course, reflected that the majority of the studies reviewed in the article were cannulation studies. I told him I thought he misused the word “paradigm”; he really meant “model,” and if he had chosen that word instead, the acronym would have been “TIM.” From that point on, I think he viewed it as a missed opportunity, but I know he appreciated the humor as I overheard him retelling the story to students and colleagues on several occasions. Tim was serious about science but never once took himself too seriously.
Tim Bartness and his lab group celebrating in 2013.
During much of his career at Georgia State University, Tim continued to employ seasonal changes in body mass and adiposity in hamsters as a useful model for the study of naturally occurring obesity. These hamsters undergo a ~30% increase in body fat simply upon transfer from short to long photoperiod in the lab—literally at the flip of a switch. Tim was able to conduct numerous groundbreaking studies regarding the neural mechanisms that regulate energetics and adiposity. Tim was prescient in identifying obesity as a “disease of literally and figuratively enormous proportions” (a turn of phrase he was fond of using). He was among the first to define the sympathetic nervous system (SNS) outflow from brain to adipose tissues and to show that melatonin receptors are co-localized with the SNS neurons innervating fat. During my time in Tim’s lab, the studies demonstrating SNS innervation of adipose tissue were going full bore; I gained a wealth of knowledge and skills in Tim’s lab. He taught me to use high-performance liquid chromatography to measure catecholamine content in peripheral tissues, to surgically and chemically denervate adipose tissue, to map neural circuits from brain to fat by use of the transneuronal tract tracer pseudorabies virus (PRV), and to tell the difference between a Siberian and Syrian hamster. But most of all, Tim taught me how to conduct rigorous science and have fun doing it.
Tim was a pioneer in the study of the autonomic regulation of adiposity and metabolism and one of the first to identify the precise neural connections between brain and fat. Despite his proper place among the preeminent scientists and scholars in the field of metabolism and energetics, it is Tim’s generosity, sense of humor, and love of life, family, and friends that I will cherish most. I will miss Tim. We all will miss him. He left us way too soon for sure, but I am a better man for knowing him.
In Memory of a Wonderful Colleague and Friend
Bruce Goldman
I first met Tim when he and George Wade (Tim’s postdoctoral advisor at the University of Massachusetts) visited me at the Worcester Foundation for Experimental Biology. They had come to obtain some Siberian hamsters from my colony and to discuss their plans to use the animals in their studies of the regulation of adipose tissue. While I do not remember this meeting in detail, I have been told that Tim did most of the talking. Tim later joined my laboratory at Worcester to continue his postdoctoral research. There Tim performed several studies of the mechanisms of pineal melatonin involvement in various seasonal responses in Siberian hamsters. These studies not only were a significant contribution to the understanding of melatonin action but also provided Tim with information that he would use to great advantage after he established his laboratory at Georgia State.
Scientists who have studied photoperiodism in mammals have long struggled with attempts to provide clinical relevance for their research. To this day, there is no clear evidence that humans experience photoperiod-cued responses like those seen in a large variety of other mammals. But Tim made use of his knowledge of chronobiology to probe a problem of the utmost clinical significance. He studied the regulation of adipose tissue in hamsters in which seasonal, photoperiod-influenced changes in body fat content are a natural and presumably adaptive phenomenon. In these studies, Tim made use of his excellent firsthand knowledge of the mammalian photoperiodic system to design experiments that yielded considerable novel information on the physiological mechanisms that regulate adipose tissue metabolism. These studies were designed to take advantage of day length–cued cycles of adipose metabolism to provide basic information that would almost surely be directly applicable to both photoperiodic and nonphotoperiodic mammals. Tim’s research focused largely on interactions between the nervous system and adipose tissue. He also carried out considerable research on the related topics of food hoarding and ingestive behavior. The information obtained from these studies has been widely recognized for its considerable clinical relevance, and a detailed review of Tim’s contributions to the fields of ingestive behaviors and obesity has been published (Grill and Levine, 2015). Tim’s very clever approach and, more important, the results of his research should give all chronobiologists a large measure of comfort. His work should also be appreciated by those who study fat metabolism as an example of the potential benefits of exploiting chronobiology for seemingly unrelated fields of research.
Tim’s interest in food intake and metabolism dated at least to his time as a graduate student; his PhD thesis dealt with the neural control of food and water intake. His postdoctoral research on melatonin and mechanisms of photoperiodism was a part of his preparation for a fresh approach to these aspects of metabolism. Along the way, Tim made some very important contributions to photoperiodism research. He collaborated with Eric Bittman to show that SCN lesions prevented the action of exogenous melatonin signals on the reproductive system in Siberian hamsters, a precursor to later findings implicating the SCN as a target site for melatonin action in this species. With Kay Song, he discovered that melatonin receptors and arginine vasopressin mRNAs are coexpressed in some SCN cells, suggesting that SCN vasopressin output might mediate some of the effects of melatonin on seasonal or circadian responses.
It is appropriate to review Tim’s remarkable scientific accomplishments in this memorial. However, to me, and I am sure to others who have known Tim well, a mere summary of his prolific contributions to the scientific record would miss Tim’s most memorable features. Tim was one of the kindest and most appreciative individuals I have been privileged to know. The more I got to know him, the more amazed and admiring I became of the life Tim led. Most recently, reading the many accolades from his former students made me feel a sense of comfort in knowing how many people were able to benefit as I did from Tim’s spirit of giving of himself to his students and colleagues. It is the opportunity to know people like Tim that, more than anything else, has made a career in research rewarding to me.
I have fond memories of conversations with Tim and Elliott Albers over lunches at the Worcester Foundation. I also vividly remember spending time with Tim at a meeting titled “Melatonin after Four Decades” in Hamburg followed by a trip on the train to Paris, where Tim put on his other hat to attend a meeting on adipose regulation and ingestive behavior while I took time off from science to visit a cousin and tour the city.
Tim’s excellent sense of humor deserves special mention. This was expressed whenever I was in his company whether privately or at public events. His humor was expressive of his gentle and kind personality.
Tim’s love for his children, Lacey and Zach, was very evident, and he spoke of them with pride whenever I met with him. Tim was also very devoted to his partner and helpmate, Ruth Harris. It is fortunate that Tim had Ruth and his children with him through the illness that claimed his life.
There are always things one wishes one had said to a person who has left us. To Tim, I know that many of us would want to say, “Thanks.”
A Farewell to My Friend and Colleague
Elliott Albers
Tim and I shared common geography throughout our careers. In 1979, before we knew each other, we each gave our first research presentations as graduate students in the same session at the Southeastern Psychological Association meeting in New Orleans, a shared career launch that we discovered years later. Subsequently, we both worked with Bruce Goldman at the Worcester Foundation, followed by over 25 years as colleagues at Georgia State University in downtown Atlanta. Our time in Bruce’s lab was truly formative for both of us, as Bruce revealed the pure joy of doing science and we did our best to adopt his positive and successful approach to discovery. When thinking of Tim, most of us focus on his remarkable scholarship and his productivity as a research scientist. I will leave to others a review of Tim’s substantial and influential contributions to neuroscience and instead will reminisce on the personal traits that made him an interesting character and valuable role model for colleagues and trainees alike.
Tim was an intense man, but one who tempered that intensity with humor and friendship. Over the many years we spent together, I cannot remember an angry word between us. I cannot say, however, that I never saw Tim angry. In an early career incident when Tim received a critical review of one of his papers, he immediately composed a long, detailed rebuttal to the editor and mailed it without hesitation. The response from the editor did not show, shall we say, appreciation for Tim’s views, and the editor’s final decision on the manuscript was flat out rejection, clearly not to Tim’s liking. Nevertheless, Tim continued throughout his career to write long and passionate letters to editors detailing the errors in their reviews—he just didn’t mail them. Instead, he used the process to think carefully about the reviews and the next steps that should (or should not) proceed from them. A purely positive element of Tim’s intensity was his grantsmanship. It is not hyperbole to state that Tim spent years writing each of his many grant applications. His dedication was usually rewarded; he was remarkably successful in being funded on the first submission. Unbelievably, though, on those rare occasions when the applications were not funded on the first review, he would not revise and resubmit; he simply started over on a different proposal. He had plenty of ideas about how best to ask and answer his scientific questions and did not waste time in pursuit of those ideas with flaws, real or perceived.
Tim was also an incredible mentor. Like many of us, he worked very hard to positively influence the development of his students and postdocs. And Tim also had a major impact on many students who were affiliated with him in other ways. As one robust example, Tim developed and taught for many years a course called Survival Skills that explored the practices, habits, and talents of successful individuals in research careers and academia. He was particularly famous for sending a parting email to graduates from his course that contained advice worth repeating:
Don’t worship anyone.
Use “Strong Inference” daily.
Work hard but remember to take time to think—thinking is all it’s cracked up to be. Be a human being, not a human doing.
Research is what we do for a living . . . it is not who we are.
Give back to students . . . yours, other people’s, and if they want to repay you, tell them to do the same.
You are never as good as other people think you are, and always better than you think you are.
As reflected in the advice he shared with students, one of Tim’s most defining qualities was his appreciation of and loyalty to those who formally and informally mentored him, including Robert Waldbillig and Neil Rowland at University of Florida, George Wade at the University of Massachusetts, John Morley and Allen Levine at University of Minnesota, and, of course, Bruce Goldman. Although they never formally worked together, Tim greatly appreciated Irv Zucker’s important role in his development as a senior scientist.
Despite all his outstanding contributions to neuroscience and education, one of Tim’s most significant and rewarding victories in life was over the disease of alcoholism. As Tim would say, alcoholism is the one disease that can make you a better person and improve the quality of your life. In recovery, Tim lived one day at a time and practiced gratitude, serenity, acceptance, and faith for over 17 years without a relapse. In fact, I will miss his annual email on December 5 celebrating his success over alcoholism and sharing his enthusiasm looking forward to the next year. It served as an annual reminder of both fragility and strength that can be identified in each of us. Tim was even strong enough to use his disease as a teaching moment. In class, he outlined the neuroanatomy of addiction not only to teach neural circuitry but also to let all students (and colleagues) know that he was there to listen if they needed help to make a change.
Tim’s life was truly influential—he mattered greatly to his students, colleagues, friends, his children Lacey and Zach, and to Ruth. I will miss his spontaneous humor and infamous snarky comments, such as this one for pernicious colleagues unable to hold their tongues: “No GABA today, eh?” I will miss our conversations about science, grants, study sections, students, administrators, life. It is hard to believe he is gone from among us. His influence will carry on through our memories and our teachings.
An Enduring Friendship
Irving Zucker
Tim and I maintained contact for 3 decades, sometimes weekly, but more often in lengthy telephone conversations several times a year. We initially connected because George Wade, who was Tim’s postdoctoral mentor and had played a major role in his scientific evolution, had formerly been my student. I was honored that Tim considered me his academic grandfather.
Tim was passionate and intense; he held views strongly, was witty, and possessed a well-developed sense of humor. Once launched on any activity, his pursuit was all consuming. We shared an interest in jazz and both took up the saxophone late in life. Although he got started several years after me, in no time he was far more adept and knowledgeable. The avidity and speed with which he amassed a huge CD collection was stunning. His relentless intensity derived from an addictive personality that often worked for him but sometimes against him.
Tim was preternaturally loyal. He was instrumental in organizing festschrifts for his mentors George Wade and Bruce Goldman, whom he revered. He generously supported younger scientists. A few years ago, he helped my former student secure an excellent faculty position. When I thanked him, he reminded me that it was repayment for what others had done to launch his career.
Tim loved to laugh and was not averse to practical jokes. At one Society for Research on Biological Rhythms meeting, Tim and I arranged for messages to be left asking Bruce Goldman to remove a nonexistent barking dog from his room. The frequent messages convinced Bruce that a dog had been planted in his room and he ran off to investigate.
Tim was a gifted, caring, concerned scientist who fostered critical thinking; he demonstrated that the scientific enterprise, for all its challenges, can also be lots of fun. The care he lavished on his students was widely acknowledged and appreciated. We have lost a dear friend whose untimely death deprived our community of a vibrant brilliant scientist; we are fortunate to have crossed his path.
Footnotes
Acknowledgements
We are grateful to Tim’s partner Ruth Harris and his colleague Vitaly Ryu for providing photographs.