BAC transgenics to monitor pathway-specific striatal projection neuron physiology
Zac Caffall has designed an automated high-throughput screen to correct a cellular abnormality associated with the mutated protein that causes Dyt1 dystonia. We used it in a genome-wide silencing RNA screen. This gives us a roadmap of genes and cellular processes that modify Dyt1 cell pathology to guide us toward new treatments. Our lab is now working on a large scale drug-library screen in collaboration with the National Center for Advancing Translational Sciences (NCATS) at the NIH.
Calcium indicators provide an opportunity to perform optical physiology in large numbers of cells simultaneously. Here courtesy of K. Ade, simultaneous acquisition of electrical (top) and fluorescence (bottom) data in a single cell shows how fluorescent reporter dyes change intensity when an action potential fires (red trace) but not significantly at subthreshold membrane depolarizations.
Our first 2p rig built by Kristen Ade gives us a unique view into how direct and indirect pathways of striatum are regulated in health and disease.
The striatum receives inputs from many areas of the brain and conveys action-related information to the basal ganglia via the direct and indirect pathways. It was long thought that an imbalance between these pathways could alter behavior, but relativistic measurements had proven elusive. By imaging activity in both pathways simultaneously, we found that relative pathway timing predicted how habitually individual mice had behaved.
In this illustration by Miranda Shipman, a bookie looks through special binoculars to pick the winner of a horse race. He sees the odds are stacked in favor of the horse, “Habit”, who has a head-start on the line, reflecting the timing bias in which firing of the direct or “Go” pathway precedes the indirect pathway, and is more muscular, reflecting the strengthening of both the direct and indirect pathways. email@example.com
The 2015 lab group (and progeny and pets) chillaxing at nearby Eastwood Lake.
2015 lab outing to the U.S. National Whitewater Center.
Hipsters or posers? You be the judge – it was Halloween after all. Miranda Shipman, our “miracle maker” and resident artist and Zac Caffall, biochemist extraordinaire and all-around go-to guy.
Autaptic microisland neuronal culture expressing fluorescent reporter.
Circuit-specific physiology of striatum facilitated by transgenic reporters of cell-type. Shown here are fluorescent cells in striatum reported by our Drd1a-tdTomato line 6 (Ade et al., 2011; Shuen et al., 2008) and the Drd2-EGFP GENSAT line (Gong et al.,2003 ).
In this study, we first started thinking more about the possible role of rare variants in known dystonia for causing the more common, sporadic forms of focal dystonia (Calakos and Patel et al., 2009).
Low-mag view of striatum showing medium spiny neurons in all their glory…… (Color from Drd1a-tdTomato and Drd2-EGFP cell reporters).
Duke in Spring is a wonderful thing.
Lab alums, Yehong Wan (front) and Viren Patel (rear) floating on the Eno River just minutes from the Duke campus.
Working model for effect of SAPAP/GKAPs on regulation of mGluRs and downstream synaptic physiology.
Molecular dissection of mossy fiber LTP mechanisms using in vivo viral injection of dentate gyrus. Virally-expressed EGFP illuminates dentate gyrus and mossy fiber tract.
The Calakos Lab – 2010