Using Scientifica electrophysiology equipment to investigate blue light responses in crab stomatogastric ganglion neurons
A recent journal publication in Current Biology by The Marder Lab at Brandeis University (Massachusetts) uses the Scientifica SliceScope and the Scientifica PatchStar Micromanipulator for electrophysiology experiments.
One of the fundamental problems in neuroscience is understanding how circuit function arises from the intrinsic properties of individual neurons and their synaptic connections. Of particular interest to The Marder Lab today is the extent to which similar circuit outputs can be generated by multiple mechanisms, both in different individual animals, or in the same animal over its life-time. The lab employs electrophysiological, biophysical, computational, anatomical, biochemical, and molecular techniques to address its research questions.
About the Study
In many animals, the daily cycling of light is a key environmental cue, encoded in part by specialized light-sensitive neurons without visual functions. We serendipitously discovered innate light-responsiveness while imaging the extensively studied stomatogastric ganglion (STG) of the crab, Cancer borealis. The STG houses a motor circuit that controls the rhythmic contractions of the foregut, and the system has facilitated deep understanding of circuit function and neuromodulation. We illuminated the crab STG in vitro with different wavelengths and amplitudes of light and found a dose-dependent increase in neuronal activity upon exposure to blue light (λ460–500 nm). The response was elevated in the absence of neuromodulatory inputs to the STG. The pacemaker kernel that drives the network rhythm was responsive to light when synaptically isolated, and light shifted the threshold for slow wave and spike activity in the hyperpolarized direction, accounting for the increased activity patterns. Cryptochromes are evolutionarily conserved blue-light photoreceptors that are involved in circadian behaviors. Their activation by light can lead to enhanced neuronal activity. We identified cryptochrome sequences in the C. borealis transcriptome as potential mediators of this response and confirmed their expression in pyloric dilator (PD) neurons, which are part of the pacemaker kernel, by single-cell RNA-seq analysis.
The Scientifica SliceScope is an ultra-stable, versatile upright microscope. The unbeatable small footprint, low noise electronics, simple conversion between in vitro and in vivo as well as the remote control, have made the SliceScope an integral part of electrophysiology rigs and multiphoton systems around the world.
Scientifica PatchStar Micromanipulator
The perfect electrophysiology micromanipulator – from single channels to in vivo
field recordings. The stable design and ultra-quiet electronics mean
you can perform long-term patch clamp experiments and record even the
Kedia, S. & Marder, E. (2022). Blue light responses in Cancer borealis stomatogastric ganglion neurons. Current Biology, 32(6), 1439-1445. https://doi.org/10.1016/j.cub.2022.01.064