Author Archives: Tom Arnold

Introduction to our laboratory

I’m a member of the Biology department and the program in Biochemistry & Molecular Biology at Dickinson College.  I’m also affiliated with the Environmental Studies Department and have held a variety of positions at other institutions, including at the University of Queensland, the Smithsonian Institution, and the College of Charleston.  I am a broadly-trained  biochemist who studies the natural products of plants and marine organisms.  Many of these serve as anti-microbials, herbivore deterrents, or chemical cues.  Some are potential new medicines or dietary supplements.  We Continue reading →

Preface – Alzheimer’s Afternoons quick summaries

New developments in our understanding of ApoE and late onset Alzheimer’s disease In early 2020 a special issue of the journal Neurobiology of Disease was published containing eleven articles exploring the role of the ApoE risk gene in the development of late onset Alzheimer’s disease.  This open access journal issue was edited by Allan Butterfield and Lance Johnson and can be found here: This was followed by the establishment of a popular online seminar series, Alzheimer’s Afternoons, organized by Lance Johnson and Rik van Continue reading →

Alzheimer’s Afternoons Seminar: Elizabeth Head

Dr. Elizabeth Head, Professor, University of California Irvine Alzheimer’s disease in Down syndrome: Link between Cerebrovascular pathology On Thursday, May 14, 2020 Dr. Liz Head presented her work on Alzheimer’s disease in Down Syndrome. Why is it useful to study the pathology of AD that is associated with Down syndrome?  Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.  This same chromosome carries the gene for the amyloid precursor protein (APP), as well as genes associated with the Continue reading →

Alzheimer’s Afternoons Seminar: Kristen Zuloaga

Sex differences in metabolic and vascular contributions to dementia. April 30, 2020 Dr. Kristen Zuloaga is an Associate Professor of Neuroscience and Experimental Therapeutics (DNET) at Albany Medical College.  A list of her group’s recent publications can be found here: (Her group has one of the best lab logos too!) Her seminar focused on sex differences in metabolic and vascular contributions to dementia. Dr. Zuloaga is interested in several different types of dementia, including classical forms of Alzheimer’s disease and vascular contributions to cognitive Continue reading →

Alzheimer’s Afternoon Seminar Series: Shannon Macauley

April 28, 2020 Targeting vascular KATP channel activity in Alzheimer’s disease Takeaway: Sulfonylurea drugs used to treat diabetes seem to inhibit the accumulation of Aβ by restoring vascular health and calming neuronal activity in the brain. Dr. Shannon Macauley is an Assistant Professor of Gerontology and Geriatric Medicine at the Wake Forest School of Medicine.  She is interested in the connections between two “diseases of aging”, Alzheimer’s disease (AD) and type 2 diabetes. She uses mouse models to study “how metabolic perturbations, either systemically or Continue reading →

Alzheimer’s Afternoons Seminar Series: Heather Wilkins

Alzheimer’s Afternoon Seminar Series APP and Bioenergetics Dr. Heather Wilkins, University of Kansas Medical Center April 23, 2020 Dr. Wilkins began by reviewing the “Amlyoid Cascade” and the “Phosphorylated Tau” theories of Alzheimer’s disease (AD), noting their similarities.  She is, however, most interested in a third theory, called the “Mitochondrial Hypothesis” which posits that mitochondrial dysfunction is the first step in the development of Alzheimer’s Disease.  She proposed that mitochondrial dysfunction eventually leads to the aggregation of AB and p-tau.  While mitochondrial dysfunction is commonly Continue reading →

Alzheimer’s Afternoons Seminar Series: Constanza Cortes

Enhanced skeletal muscle as a novel determinant of CNS aging and Alzheimer’s disease  Alzheimer’s Afternoons Seminar Series (April 21) Dr. Constanza J. Cortes, Brain Aging Physiology Lab, University of Alabama Birmingham Takeaway: A robust lysosomal waste disposal system in muscle tissue promotes healthy cognition in aging mice and those predisposed to Alzheimer’s disease.  The link seems to be the secretion of myokines by young, exercised muscle tissue, which circulates to the central nervous system and supports brain health. Dr. Cortes is interested in how distant Continue reading →

Alzheimer’s Afternoons Seminar: Julia TCW

Cholesterol and matrisome networks in Alzheimer’s disease Alzheimer’s Afternoons Seminar Series (April 16) Dr. Julia TCW is an Instructor at the Icahn School of Medicine at Mount Sinai in New York (USA).  She uses human induced pluripotent stem cells (iPSC), transgenic mouse models, and human tissue samples to explore the effects of the apoe4 risk gene on gene expression and metabolism.  Her talk touches on several different projects, including some related to the following open-access articles: Reduced variability of neural progenitor cells and improved purity Continue reading →

Alzheimer’s Afternoons Seminar: Misha Zilberter

Alzheimer’s disease and epilepsy: what can we learn from their similarities? Alzheimer’s Afternoons Seminar Series (April 14) Dr. Misha Zilberter, a staff research scientist from the Gladstone Institutes at the University of California San Francisco Medical Center, presented a seminar entitled “Brain glucose hypometabolism and network hyperexcitability in Alzheimer’s disease”. For more information consider reading their open access article: The vicious circle of hypometabolism in neurodegenerative diseases: Ways and mechanisms of metabolic correction Yuri Zilberter Misha Zilberter 02 May 2017 Dr. Zilberter began by Continue reading →

Alzheimer’s Afternoons Seminar: Rik van der Kant

Cholesterol, Apoe4, and Alzheimer’s disease Alzheimer’s Afternoons Seminar Series (April 2) This seminar was presented by Dr. Rik van der Kant, a Research Associate in both the Faculty of Science, (Functional Genomics) and Amsterdam Neuroscience (Neurodegeneration) at Vrije Universiteit Amsterdam.  He is an expert on cholesterol metabolism and is studying how apoe4 contributes to LOAD.  The title of his seminar was “Cholesterol metabolism as a dual driver of neuronal AD pathology”.  He described his recent work that was published (open access) here: van der Kant, Continue reading →

Alzheimer’s Afternoons Seminar: Gareth Howell

Alzheimer’s Disease: next generation mouse models Alzheimer’s Afternoons Seminar Series (March 31) Gareth Howell This seminar was presented by Dr. Gareth Howell, Associate Professor and the Diana Davis Spencer Foundation Chair for Glaucoma Research at the Jackson Lab.  His premise was that progress in AD research has been hindered by poor mouse models.  He is a member of the MODEL-AD group, a collection of hundreds of researchers working to create and test next-generation mouse models. He began by describing new mouse models developed with human Continue reading →

Alzheimer’s Afternoons Seminar: Lance Johnson

Alzheimer’s Disease: Tipping the energy balance Alzheimer’s Afternoons Seminar Series (March 26) Lance Johnson The Alzheimer’s Afternoons Seminar Series started off with a seminar by Dr. Lance Johnson from the University of Kentucky.  Dr. Johnson is one of the organizers of the popular online seminar series but also a guest editor (along with Allan Butterfield) for a special issue of the journal Neurobiology of Disease containing eleven articles on ApoE and Alzheimer’s.  The open access articles (technically published in June 2020, but available online in Continue reading →

Natural HDAC inhibitors alter histones, gene expression, and development

Our work with HDACis from plants, microbes, and other organisms demonstrates the role of these molecules in nature.  Here they alter development of common insects by changing patters of histone acetylation and gene expression.  In these model organisms plant-derived HDACis have biochemical activities which may make them useful in the treatment of neurological disorders in human subjects.

How to request letters of recommendation

Requesting letters of recommendation I frequently write letters of recommendation for students I know well, e.g. those I have mentored in the laboratory or taught in several courses.  Strong letters can help you compete for fellowships and awards, enter into graduate programs, or land jobs. When you approach a faculty member about writing a letter of support remember that you want a STRONG letter from someone who knows you well.  Letters that are weak or written by someone who doesn’t know you well are generally Continue reading →