Research Thrusts

Dali Sames, Overview of a representative dopaminergic synapse and labeling by FFNs and APP+

Overview of a representative dopaminergic synapse and labeling by FFNs and APP+. (A) Dopamine is synthesized in the DA neuron and packaged into synaptic vesicles by the action of VMAT2 (blue ovals). Upon arrival of an action potential, DA is released via exocytosis into the synaptic cleft and extrasynaptic space where it interacts with pre- and postsynaptic dopamine receptors, and […]

Dali Sames, pH-responsive FFNs

We introduce pH-responsive fluorescent false neurotransmitters (pH-responsive FFNs) as novel probes that act as vesicular monoamine transporter (VMAT) substrates and ratiometric fluorescent pH sensors. The development of these agents was achieved by systematic molecular design that integrated several structural elements, including the aminoethyl group (VMAT recognition), halogenated hydroxy-coumarin core (ratiometric optical pH sensing in the desired pH range), and N- […]

Franck Polleux, Labeling of the millions of axons crossing the internal capsule of the mouse embryo

Labeling of the millions of axons crossing the internal capsule of the mouse embryo. Red:neurofilament 165kD staining. Green: EGFP form the Ngn2 EGFP-KI knockin mice provided by Dr. Francois Guillemot. Horizontal Sections. Modified from Seibt J1, Schuurmans C, Gradwhol G, Dehay C, Vanderhaeghen P, Guillemot F, Polleux F. Neurogenin2 specifies the connectivity of thalamic neurons by controlling axon responsiveness to […]

Franck Polleux, Callosal axon branching

Callosal axon branching (green, contralateral side) labeled by in utero cortical electroporation at E15, examined at P21 (from Julien Courchet). Red counterstaining (Cux1) labels layer 2-4. Modified from: Courchet J.*, Lewis T. Jr *, Aizawa S. and Polleux F. (2013) Terminal axon branching is regulated by the LKB1-NUAK1 kinase pathway via presynaptic mitochondrial capture. Cell 153:1510-1525.

Jonathan Owen, Research Statement

The photoluminescence of inorganic QDs is inherently voltage sensitive due to the quantum confined Stark effect. Incident electric fields present at the neuron membrane surface influence the luminescence energy, which can be read out using steady state luminescence measurements.  When coupled with a transition metal dopant QD, the change in energy can be readout from the ratio of the red […]

Wei Min, Research Statement

Live-cell imaging with alkyne-tagged small biomolecules by stimulated Raman Scattering. The introduction of GFP has revolutionized life sciences and biomedicine. At the same time, smaller biomolecules, such as nucleosides, amino acids, choline, fatty acids, metabolites and drugs, play indispensable roles inside cells, yet are too small to be tagged with fluorescent proteins. In fact, despite the extensive efforts, sensitive and […]

Virginia Cornish, Research Statement

Chemical tags are now viable alternatives to fluorescent proteins for labeling proteins in living cells with organic fluorophores that have improved brightness and other specialized properties. Recently, we successfully rendered our TMP-tag covalent with a proximity-induced reaction between the protein tag and the ligand-fluorophore label. This initial design, however, suffered from slow in vitro labeling kinetics and limited live cell […]

Ken Shepard, Research Statement

We have made significant progress on the development of dense electrophysiological recording platforms exploiting CMOS technology. We have previously demonstrated a 56,000-channel in vitro MEAs for electrical stimulation of neurons.  In this project, this MEA has been extended with recording capabilities. This new MEA supports a per-electrode bandwidth of 10 kHz with a sample-rate of 20 kSa/s when recording from […]

Ozgur Sahin, Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators

(a) Side view of a rotary engine. Wet paper provides the humidity gradient. Blue plastic blocks weighing 15 mg attached to HYDRAs increase the amount of mass shifting position relative to the axis of rotation. (b) Photos and (c) measurements showing the horizontal shifts in the positions of plastic blocks attached to HYDRAs. Markers indicate the average data values with error […]

Aurel Lazar, Reconstructing Natural Visual Scenes From Spike Times

A single neuron is not sufficient to represent an entire visual scene. An ensemble of neurons with different receptive fields tiling the visual space is needed. Fig. 2 schematically illustrates a class of neural circuit architectures for encoding visual scenes (signals). A space-time varying signal is encoded by a parallel neural circuit consisting of neurons, each composed of a spatio–temporal […]