Techniques/equipment that we use
Our lab is driven by questions about the neural systems that we study. We use techniques to answer these questions and import new ones (or collaborate) as needed. Having said that, many incoming students/postdocs want to know what we routinely do and what we have. Below are some techniques you can expect to use and learn as a member of our team.
High-throughput electrophysiology
Our lab is equipped with two Maxwell MaxOne multielectrode arrays (https://www.mxwbio.com/) that enable extracecullar recordings of retinas and brain slices. These arrays have ~26’400 electrodes and can be configured to simultaneously record action potentials from 1000 neurons. We currently use these to probe spontaneous activity in developing circuits and light-mediated responses in adult retinas.
Action potentials recorded from multiple retinal ganglion cells from a single electrode (out of ~1000).
Raster plot of neural activity from individual neurons (y axis) over time (x-axis). Each dot is an action potential. The big streaks are travelling retinal waves.
Two-photon Calcium imaging
Our lab is equipped with a Sutter Moveable Objective Microscope that is capable of fast volumetric imaging.
Imaging calcium signals in retinal ganglion cell as they respond to retinal waves and visual stimuli (denoted by white bar at top right)
Anatomical techniques and (more) microscopy
We use a variety of anatomical techniques to understand the organization of the nervous system. Example techniques include immunohistochemistry and neuron tract tracing. Tissue is typically imaged on our own Zeiss Axio Imaging M2 microscope equipped with Apotome deconvolution technology or on one of the many core microscopes available to our lab (e.g.: confocal, fast tile scanner, light-sheet microscope).
Immunostaining
Cross section of a retina stained for ChAT (cholinergic neurons, green) and HR1 (histamine receptors, magenta) using IHC.
Neuron tract tracing Axon terminals from the right (green) and left (magenta) eyes in the visual thalamus, labelled with anterograde tracers.
Computational techniques
While we are mostly a wet lab, the data we collect is high-throughput and requires computer programming to analyze. We use MATLAB to design analysis pipelines that allow us to manage datasets and ask any questions we want from it. New students without programming experience should not be intimidated by this. I teach the Programming for Biologists course at Vanderbilt and members of the Tiriac lab often join without programming experience and quickly pick up on it. In fact, I believe this is a skill you might want to learn in today’s modern scientific environment - experience in my lab will teach it to you.