Extracellular Recording of Electrical Activity in the Drosophila Central Nervous System

Abstract

Source: Swale, D. R., et al. Electrophysiological Recording of The Central Nervous System Activity of Third-Instar Drosophila Melanogaster. J. Vis. Exp. (2018)

The video demonstrates the extracellular recording of neuronal activity from the central nervous system (CNS) of Drosophila larvae. The transected CNS is positioned in a recording chamber, and the electrical activity from a descending nerve is recorded to establish the baseline firing frequency. A test agent is then introduced, and the change in firing frequency is recorded to determine the agent's excitatory or inhibitory effect.

Protocol

All procedures involving sample collection have been performed in accordance with the institute's IRB guidelines.

1. Dissect and Prepare the Larval Drosophila CNS

NOTE: Methods for larval CNS dissection are clearly illustrated in Hafer and Schedl, but these previously published methods reduce the length of the descending neurons that are important for measuring spike frequency. Here, an additional method is outlined to excise the larval CNS that maintains long, intact descending neurons.

1. Saline preparation.
   1. Prepare the dissection and recording sal....

Results

Figure 1: Method for excising the CNS from third-instar maggots. (A) Intact maggot submerged in 200 µL of saline. The arrow indicates the mouth hooks that are used for separation of the body wall. (B) Two pairs of forceps are placed in .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Drosophila melanogaster (strain OR)	Bloomington Drosophila Stock Center	2376
Vibration isolation table	Kinetic Systems	9200 series
Faraday Cage	Kinetic Systems	N/A
Dissecting Microscope on a Boom	Nikon	SMZ800N	Multiple scopes can be used; boom stand is critical
AC/DC differential amplifier	ADInstruments	AM3000H	The model 1700 can be used instead of the model 3000
audio monitor	ADInstruments	AM3300
Hum Bug Noise Eliminator	A-M Systems	726300
Data Acquisition System (PowerLab)	ADInstruments	PL3504	Multiple PowerLab models can be used.
Lab Chart Pro Software	ADInstruments	N/A - Online Download
Fiber Optic Lights	Edmund Optics	89-740	Different light sources can be used, but fiber optics are the most adaptable
Micromanipulator	World Precision Instruments	M325
Microelectrode Holder	World Precision Instruments	MEH715	Different models are acceptable
BNC cables	World Precision Instruments	multiple based on size
Glass Capillaries	World Precision Instruments	PG52151-4
Microelectrode Puller	Sutter Instruments	P-1000	Also can use Narashige PC-100
Black Wax	Carolina Biological Supply	974228
Non-coated insect pins, size #2	Bioquip	1208S2
Fince Forceps	Fine Science Tools	11254-20
Vannas Spring Scissors	Fine Science Tools	15000-03