Extracellular Recording of Electrical Activity in the Drosophila Central Nervous System
Trascrizione
To begin, first, pull the glass pipette electrode from borosilicate glass capillaries to a resistance of 5 to 15 megaohms. Insert the transected CNS into a wax chamber containing 200 microliters of saline. Clamp an uncoated insect pin with an alligator clip soldered to the ground wire, and insert the pin into the saline to complete the circuit. Using the micromanipulators, orient the electrode to the caudal end of the transected CNS.
Eliminate background noise by adjusting the threshold level in the acquisition analysis software prior to connecting the peripheral nerve trunks. Apply slight negative pressure on the syringe to draw peripheral nerves into the suction electrode. Start the recording on the data acquisition software, and allow the baseline firing rate to equilibrate for five minutes prior to collecting baseline firing rate data.
After five minutes, add 200 microliters of saline and vehicle to bring the total volume of the chamber to 400 microliters to begin recording control firing rates. Discard the preparation and recording if the pattern of firing of control treatment is not similar to the example shown here.
When baseline has been established after 3 to 5 minutes of recording, withdraw 200 microliters of saline and add 200 microliters of the experimental agent solubilized in saline. Label this time point of drug application in the acquisition analysis software by including a comment that includes the drug and the final concentration.
