SUB NEURONAL LOCALIZATION OF ION CHANNELS IN THE PRECISELY FIRING MOTONEURON B1

The Drosophila direct basalar b1 steering muscle is part of the wing hing and enables steering maneuvers on a cycle-by-cycle time scale (Dickenson & Tu, 1997). The muscle is innervated by one b1 motoneuron, which fires tonically once per wing beat cycle, to ensure the function of the b1 muscle reliably (Bartussek & Lehmann, 2018). The b1 motor neuron´s structure shows few, thick dendrites, with a large axon diameter and large synaptic boutons to enable fast action potential integration and conduction as well as synaptic transmission (Bartussek & Lehmann, 2018 & Lehmann & Bartussek, 2016). Therefore, the precise expression of voltage gated ion channels is very important to generate proper function.
This study uses the genetic tools of Drosophila to specifically target these ion channels and investigated in the sub-neuronal expression of voltage gated ion channels and their different splice variants in the b1 motor neuron.
We find, by using the FLP-Tag method, that the sodium channel para, which is important for generation of action potential (Loughney et. al., 1989), is forming a clearly defined spike initiation zone.
In general, our data allows us to couple sub-neuronal expressions of ion channels to the b1 motor neuron function.