Elucidating Neuronal Circuitry
Electrophysiology
Patch-clamp electrophysiology is the Gold Standard approach in Neuroscience for measuring action potentials, synaptic events and ion channel activities.
32-channel Behavior and
Awake In Vivo Recording
This approach enables us to reliably determine neuronal excitability and network excitation-inhibition balance by recording neuronal action potentials at the population level and network operation at many assessment points.
Opto & Chemogenetics
These cutting edge technologies are leveraged to anatomically tracing axonal projections of a specific population of neurons in the brain regardless of distance and selectively manipulate activities of these cells and related circuits. Both can be integrated with electrophysiology or behavioral assays for functional readouts.
Confocal image of a coronal mouse olfactory bulb (OB) section.
Red: ChR2-mCherry expression in CCKergic projection neurons;
Green: GFP expression in dopaminergic interneurons
Confocal image of a coronal mouse olfactory bulb (OB) section.
Red: ChR2-mCherry expression in CCKergic projection neurons;
Green: GFP expression in GABAergic interneurons
A recorded CCKergic projection neuron in the mouse OB.
Red: Biocytin-CY3 labeling
Green: ChR2-EYFP
Relationship between CCKergic projection neurons and GABAeric interneurons in the OB
Red: ChR2-mCherry expression in CCKergic projection neurons;
Green: GFP expression in GABAergic interneurons
ChR2-EYFP expression in OB dopaminergic interneuron
A: horizontal OB section.
B: dopaminergic interneurons expressing tyrosine hydroxylase (TH) and ChR2-EFYP.
C: reconstruction of a recorded OB dopaminergic interneuron.
ChR2-EYFP expression in OB mitral cell axons projecting to the lateral entorhinal cortex (LEC)
A: schematic illustrating virus (AAV) injection into the OB.
B: ChR2-EYFP expression in the OB.
C: coronal brain slice containing the LEC showing ChR2-EYFP expression only in layer I which receive axons projection from the OB (green).
GABAergic transmission from short axon cells (SACs) to external tufted cells (ETCs) in the OB
A: optical stimulation (blue bar) of SACs terminates spontaneous firing in ETCs in the presence of NBQX and APV .
B: Addition of gabazine (GBZ) abolishes the optical stimulation-evoked firing termination in ETCs.
Dopamine (DA) inhibits the OB-LEC transmission
A&B: representative voltage clamp traces showing the effects of DA on the excitatory postsynaptic currents (EPSCs) in LEC fan cells elicited by optical stimulation of OB projection neuron axons in LEC layer I .
In Vivo Ca2+ Imaging
FP3002 System
FP3002 is our fiber photometry system equipped with three excitation wavelengths: 470 nm for imaging of green calcium indicators (e.g. GCaMP), 560 nm for imaging of red-shifted calcium indicators (e.g. RCaMP), and 415 nm for an interleaved isosbestic control to eliminate motion artifacts (i.e. calcium-independent signals). It is also featured by Real-time processing and flexible control with a new computer interface, live data processing of 4 channels to collect analytical measurements for accurate across-subject comparisons.
Real time measurement of Ca2+ fluctuations
This allows us to simultaneously record intracellular Ca2+ activities in specific populations of neurons or glial cells from four different brain regions of the same animal or in the same brain region from 4 different animals.