Astroglia in Autism Spectrum Disorder

Abstract

Autism spectrum disorder (ASD) is an umbrella term encompassing several neurodevelopmental disorders such as Asperger syndrome or autism. It is characterised by the occurrence of distinct deficits in social behaviour and communication and repetitive patterns of behaviour. The symptoms may be of different intensity and may vary in types. Risk factors for ASD include disturbed brain homeostasis, genetic predispositions, or inflammation during the prenatal period caused by viruses or bacteria. The number of diagnosed cases is growing, but the main cause and mechanism leading to ASD is still uncertain. Recent findings from animal models and human cases highlight the contribution of glia to the ASD pathophysiology. It is known that glia cells are not only "gluing" neurons together but are key players participating in different processes crucial for proper brain functioning, including neurogenesis, synaptogenesis, inflammation, myelination, proper glutamate processing and many others. Despite the prerequisites for the involvement of glia in the processes related to the onset of autism, there are far too little data regarding the engagement of these cells in the development of ASD.

Keywords: astrocytes; autism; glia.

Figure 1

Main types of glia cells in the CNS.

Figure 2

The possible role of astrocytes in the development of autism. Genetic mutations, prenatal exposition on some drugs and prenatal inflammation affect astrocytic morphology and functions. It may result in alterations of synapse functions, imbalanced homeostasis between excitation and inhibition and dysregulation of the nervous system. This, in turn, may lead to autistic-like behavioural changes. D-Ser: D-serine; GLAST, GLT-1: glutamate transporters; Aqp4: aquaporine 4; Kir4.1: inward rectifying K⁺ channels.