Analysis of Glial Distribution in Drosophila Adult Brains

Abstract

Neurons and glia are the two major cell types in the nervous system and work closely with each other to program neuronal interplay. Traditionally, neurons are thought to be the major cells that actively regulate processes like synapse formation, plasticity, and behavioral output. Glia, on the other hand, serve a more supporting role. To date, accumulating evidence has suggested that glia are active participants in virtually every aspect of neuronal function. Despite this, fundamental features of how glia interact with neurons, and their spatial relationships, remain elusive. Here, we describe the glial cell population in Drosophila adult brains. Glial cells extend and tightly associate their processes with major structures such as the mushroom body (MB), ellipsoid body (EB), and antennal lobe (AL) in the brain. Glial cells are distributed in a more concentrated manner in the MB. Furthermore, subsets of glia exhibit distinctive association patterns around different neuronal structures. Whereas processes extended by astrocyte-like glia and ensheathing glia wrap around the MB and infiltrate into the EB and AL, cortex glia stay where cell bodies of neurons are and remain outside of the synaptic regions structured by EB or AL.

Tau‐induced deficits in nonsense‐mediated mRNA decay contribute to neurodegeneration

“…There are clear limitations, however, of using Drosophila to model human neurological disorders. Drosophila neurons are smaller and have fewer processes extending from the cell body than their vertebrate counterparts, 75,76 lack axon‐specific neurofilaments, 77 and represent the majority of cells in the central nervous system 78 . Glia are 10 times more abundant than neurons in the human brain, suggesting that an increased glia‐to‐neuron ratio represents greater brain complexity.…”

From Early to Late Neurogenesis: Neural Progenitors and the Glial Niche from a Fly’s Point of View

“…However, in the early ages of brain science, glia were thought to serve only as scaffolding for neurons and to play a passive role in the nervous system. Nowadays, in contrast to what was initially believed, it is accepted that glia also play a relevant part in brain formation, and are important not only in structural development but also in controlling stem cell division (Awasaki et al, 2008;DeSalvo et al, 2014;Kanai et al, 2018;Kriegstein and Alvarez-Buylla, 2009;Okamoto and Nishimura, 2015;Ou et al, 2016). However, more knowledge of their interaction with precursor stem cells is needed.…”

Gap junction protein Innexin2 modulates the period of free-running rhythms in Drosophila melanogaster

“…Innexin2 is widely expressed in glial cells in Drosophila both during developmental stages and in the adult brain ( Holcroft et al., 2013 ; Chaturvedi et al., 2014 ; Farca Luna et al., 2017 ). To examine if Innexin2 in glial cells contribute to modulate the free-running period, we downregulated its expression using two glial-specific drivers, repoGal4 (pan-glial driver) and alrmGal4 (expressed in astrocyte-like glia) ( Ou et al., 2016 ). Fewer flies were obtained in case of Innexin2 knockdown using repoGal4 , probably because of developmental lethality, as reported by previous studies ( Holcroft et al., 2013 ; Chaturvedi et al., 2014 ).…”