Microfluidics for in vivo imaging of neuronal and behavioral activity in Caenorhabditis elegans

Abstract

The nematode C. elegans is an excellent model organism for studying behavior at the neuronal level. Because of the organism's small size, it is challenging to deliver stimuli to C. elegans and monitor neuronal activity in a controlled environment. To address this problem, we developed two microfluidic chips, the 'behavior' chip and the 'olfactory' chip for imaging of neuronal and behavioral responses in C. elegans. We used the behavior chip to correlate the activity of AVA command interneurons with the worm locomotion pattern. We used the olfactory chip to record responses from ASH sensory neurons exposed to high-osmotic-strength stimulus. Observation of neuronal responses in these devices revealed previously unknown properties of AVA and ASH neurons. The use of these chips can be extended to correlate the activity of sensory neurons, interneurons and motor neurons with the worm's behavior.

Reciprocal inhibition between sensory ASH and ASI neurons modulates nociception and avoidance in Caenorhabditis elegans

“…2a), which has properties of high Ca 2 þ affinity, a large dynamic range and slow photobleaching 31 . A transparent polydimethylsiloxane microfluidic device was used to trap and expose worms to the Cu 2 þ stimulus 32,33 . ASHs showed an obvious on-and off-response that precisely corresponded to the presentation and removal of the noxious stimulus, respectively, following a 30-s stimulation with 10 mM CuSO 4 ( Fig.…”

Reporting neural activity with genetically encoded calcium indicators

“…Several classes of GECIs have performed well for neural imaging, encompassing single-FP and FRET sensors, and sensors based on calmodulin and troponin-C calcium-binding domains. Published GECIs are adequate for detecting high frequency bursts of neuronal activity, making them appropriate for activity localization in mouse myotubes (Nakai et al, 2001), mouse cerebellum (Diez-Garcia et al, 2005), or in invertebrate systems (Kerr et al, 2000;Higashijima et al, 2003;Wang et al, 2003;Chronis et al, 2007;Clark et al, 2007). However, reliable in vivo single-AP detection is not yet feasible with the current generation of techniques.…”

Durable spatiotemporal surveillance of Caenorhabditis elegans response to environmental cues

“…Microfluidics has been used for multiple applications in worm biology in recent years 10,11 . These applications include preparing and immobilizing worms for imaging and microsurgery 12 ; rapid control of changes in chemical environment for studies of the chemosensory system 13 ; trapping of worms for quantification of undulatory dynamics 14 ; as well as animal sorting 15 and screening 16 . In particular, several approaches to long-term imaging have been proposed [17][18][19] .…”