Developmental neural activity requires neuron-astrocyte interactions.

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Developmental neural activity is critical for neural circuit assembly.
• Glia play established roles in synapse development, but their contribution to developmental activity is understudied.
• Neuron-glia interactions are increasingly recognized as vital for neural development.

Purpose of the Study:

• To investigate the role of astrocytes in developmental neural activity during synaptogenesis in Drosophila.
• To explore the contribution of neuron-glia interactions to developmental neural activity.
• To elucidate the functional relationship between astrocytic calcium dynamics and neuronal activity.

Main Methods:

• Wide-field epifluorescence and two-photon imaging were used to monitor intracellular calcium dynamics in glia.
• Genetic ablation techniques were employed to assess the necessity of specific glial types (astrocytes, cortex, ensheathing glia) for neuronal activity.
• Neuronal activity was inhibited to observe the impact on astrocyte calcium dynamics.

Main Results:

• Central nervous system glia exhibit type-specific patterns of intracellular calcium dynamics during developmental activity.
• Genetic ablation of astrocytes significantly attenuated neuronal activity, while ablation of other glia had no such effect.
• Inhibition of neuronal activity led to the loss of astrocyte calcium dynamics, indicating a bidirectional relationship.
• Astrocytic calcium dynamics can influence neuronal activity, though they are not strictly necessary for it.

Conclusions:

• Astrocytes are necessary for developmental neural activity and synapse function during synaptogenesis in Drosophila.
• Neuron-glia interactions, particularly those involving astrocytes, are crucial for the functional maturation of synapses during development.
• This study highlights a previously underappreciated role for astrocytes in regulating the dynamic aspects of neural circuit assembly.