Nonhuman Primate Models of Neurodegenerative Disease

My postdoctoral work in Dr. Judy Cameron's lab at the University of Pittsburgh focuses on studies of the non-motor symptoms of Parkinson's disease (PD) in a nonhuman primate MPTP model.  PD is the second most common neurodegenerative disease, and patients most commonly cite the non-motor symptoms of the disease as the most debilitating and disruptive to quality of life over the motor deficits they exhibit.  However, studies of the non-motor aspects of PD in animal models are lacking, and as such current treatments are only targeted at one part of the disease.  I am characterizing motivational, cognitive, and affective behaviors (e.g. anxiety and depression) in MPTP monkey models of PD - research which has not before been conducted.  With funding from the Michael J. Fox Foundation, we are testing the efficacy of a novel drug therapy in treating both the motor and non-motor symptoms of PD.

My past research examined the neuroprotective effects of exercise in a nonhuman primate model of Parkinson's Disease (PD).  Specifically, we determined the extent to which physical activity undertaken prior to the onset of PD protected against the deterioration of motor functioning associated with the progression of PD.  Further, we are examined via PET imaging how well physical activity protected against insult to dopamine neurons in regions of the brain that are affiliated with the types of motor impairments observed in patients with PD.   We aimed to characterize physical activity as a comprehensive, non-pharmaceutical protective tool that not only ameliorates the motor deficits associated with PD, but that also targets the etiology of the disease by protecting dopamine neurons from insult against neurotoxins.  We found that monkeys with higher physical activity in the months prior to MPTP administration - whether achieved through intrinsic activity or planned exercise - were more protected against DA neuron loss and neuronal functioning, as well as against the development of motor deficits (see Society for Neuroscience abstract here).  The good news - daily, hour-long sessions on a treadmill are not necessarily required...take the stairs, park further away, just be more active!

Infant Primate Neurobehavioral Development

My Master's and Dissertation research centered around my passion for infant monkey behavior and development, which was sparked the first moment I set foot in the Infant Primate Research Laboratory as a sophomore at the University of Washington in 1999.     My mentor and dear friend, Gerry Ruppenthal (1944-2005) guided my foray into primatology, and it is to his lasting memory, doctrine,  and love for infant monkeys that I dedicate my research.  In my career, I hope to pass on some of the vast knowledge (and love of fine liquors) that he instilled in me.

My Dissertation research examined the extent to which early life experience and serotonin-transporter genotype (essentially, a nature/nurture interaction) influence chronic stress physiology as measured via hair cortisol, and how this system then predicts the development of social anxiety in juvenile monkeys.  This research has direct relevance to human populations as social anxiety is the one of the most common type of anxiety disorders and the onset usually begins in childhood or adolescence (NIMH, 2007).  I studied two cohorts of infant rhesus monkeys continually from birth through two years of age.  One exciting finding from this research was that hair cortisol values measured in the first six months of life, which represent an early physiological "phenotype," are predictive of anxious responses to a major life stressor over the next 12 months, particularly for at-risk individuals. 

My Master's work, examined the effects of two types of inanimate surrogate mothers on the neurobehavioral development of infant rhesus monkeys.  This was the first surrogate study to directly compare surrogate-reared infants to infants reared with their mothers, and my study (published in Developmental Psychobiology) found that infants reared on a swinging, vertically-oriented surrogate develop motor skills and exploratory behaviors more similar to those of  mother-reared infants than do monkeys reared on a standard rocking, horizontally-oriented surrogate found in several primate nurseries.