NEURAL ACTIVITY AFFECTS ASTROCYTE MORPHOLOGY IN DROSOPHILA MELANOGASTER
PublisherThe University of Arizona.
AbstractAstrocytes are known to maintain a proper ionic balance in the central nervous system, take up neurotransmitters after synaptic signaling, and modulate synaptic activity through a reciprocal conversation in which neuronal activity induces responses in glial cells that, in turn, modulate neuronal activity. We previously reported that constitutive RNAi knockdown of the GABA transporter in astrocyte--‐like glia of the 3rd--‐instar ventral nerve cord (VNC) strongly reduced larval locomotion, indicating that altering astrocyte function modulates activity in neurons comprising the motor circuitry (MacNamee et al., SfN abstract 2013). Here we have manipulated neural activity in the larva to assess the impact of altered neuronal activity on astrocytes. We fed larvae picrotoxin, which blocks GABAA receptors and glutamate--‐gated chloride channels and used a FLP--‐out genetic construct to visualize the detailed morphology of astrocytes in the VNC. Results to date indicate that the pharmacological treatment, which would be expected to change the balance of inhibition and excitation, significantly reduced locomotor activity and concomitantly led to a marked decrease in the volume occupied by the branching processes of astrocytes. The impact on glial morphology is being assessed using 3--‐D reconstructions of high--‐magnification confocal microscopic images.