Objectives: To develop a new method for acute isolation of the cerebral neurons from late third instar larvae of Drosophila melanogaster.
Methods: The dissociated cells were characterized by morphological observation and whole-cell voltage-clamp recording. The brains were dissected from late third instar larvae, torn into small fragments, and then were digested in the calcium-magnesium-free PBS solution endowed with collagenase for 45-60 minutes. Single cell was obtained by micro-shaking the digested fragments for 5 to 10 s until the clumps of the tissue were not invisible. Preparation of dispersed cells was incubated in the culture media of Drosophila for thirty minutes at room temperature (20 +/- 1) degrees C.
Results: All neurons studied were categorized into three types according to morphological observation: large (> 8 microm) round type I neuroblast-like cells (7%), small (2-5 microm) type II cells (77%). and intermediate-sized type II cells (16%). Neurogliocytes were not found. The electrophysiological properties of three types of neurons were investigated by whole-cell voltage-clamp recording technique. Five types of outward potassium currents were detected readily.
Conclusion: Morphological and electrophysiological investigation showed that the method for acute isolation of Drosophila neurons is simple, available and stable.