Zack Chadick

Address:
UCSF MC 2512
Byers Hall BH-102
1700 4th Street
San Francisco, CA 94158-2330

email: james.chadick@ucsf.edu
lab: 415-476-2164
fax: 415-514-4451

Web:  http://phy.ucsf.edu/~chadick

Curriculum Vita: (pdf)
   
Biography:
Originally from the Houston, Texas area, Zack moved to California in 1999 to attend the California Institute of Technology.  While at Caltech, he had the opportunity to perform a wide-variety of research from total organic-synthesis/NMR spectroscopy in the Division of Chemistry to T-cell lymphocyte lineage determination/development in the Division of Biology.  Zack graduated with honors in 2003, leaving with a double-major in biology and chemistry.

After leaving Caltech, Zack meandered south to San Diego where he worked as a research assistant with Francisco Asturias at The Scripps Reseach Institute using single-particle cryo-EM to investigate the eukaryotic transcriptional machinery.

Unable to have left the California coast for the past six years, Zack enrolled in the UCSF Neuroscience program in September of 2005.  Having been associated with the Gazzaley Lab since April of 2006, Zack formally joined the lab in September of 2006 and is currently working towards his Ph.D thesis.

Research Description:
Our lab is currently focused on exploring the interaction of attention and memory (WM) in the context of normal aging.  My current research is concerned with the relationship between both task relevant and task irrelevant (i.e. distracting) information when simultaneously presented and how this relationship is altered as the brain ages.  Previous results from the lab have shown that the degree to which a participant selectively ignores distracting information drives working memory performance.  In addition, we have also shown that older adults exhibit a marked reduction in their ability to ignore task-irrelevant information.  However, the neural origin of this suppression deficit has not been established. 

Using a combination of fMRI and EEG measures, we can simultaneous observe both the site of attentional modulation (i.e., sensory brain regions) and frontal sources of modulation (i.e., prefrontal cortex), and quantify the network interaction between the regions in healthy younger and healthy older adults.  These measures have allowed us to identify whole-brain neural networks associated with enhancement of task-relevant information and suppression of task-irrelevant information.  Consistent with the suppression-deficit model of cognitive-aging, my project has demonstrated that older adults exhibit a significantly compromised suppression network (specifically, an alteration in the control source from the anterior cingulate cortex and the medial frontal cortex), while their enhancement network is unaltered.

Now that we have established a reduced functional interaction between sources and sites of attention modulation, the next step of my project is to use high-resolution structural MRI data to investigate how age-related anatomical changes in specific brain regions (using both measures of grey matter atrophy and white matter disorganization) may be driving age-related cognitive decline.  Once we have identified specific frontal regions that are correlated with age-related cognitive decline, we will selectively disrupt these regions in healthy, young controls using transcranial magnetic stimulation (TMS) to test the causality of frontal-region degradation in age-related decline in working memory performance.

Funding:
Zack is supported by a graduate fellowship from the Larry L. Hillblom Center for Biology of Aging.

Publications:
Asturias, F. J., Chadick, J. Z. , Cheung, I. K., Stark, H., Witkowski, A., Joshi, A. K. & Smith, S. Structure and molecular organization of mammalian fatty acid synthase. Nat Struct Mol Biol 12, 225-32. (2005)

Chadick, J. Z. & Asturias, F. J. Structure of eukaryotic Mediator complexes. Trends Biochem Sci 30, 264-71. (2005).

Takagi, Y., Chadick, J. Z., Davis, J. A. & Asturias, F. J. Preponderance of free mediator in the yeast Saccharomyces cerevisiae. J Biol Chem 280, 31200-7. (2005)