Astrocytic Regulation of Neural Circuits Underlying Behaviors

Abstract

Astrocytes, characterized by a satellite-like morphology, are the most abundant type of glia in the central nervous system. Their main functions have been thought to be limited to providing homeostatic support for neurons, but recent studies have revealed that astrocytes actually actively interact with local neural circuits and play a crucial role in information processing and generating physiological and behavioral responses. Here, we review the emerging roles of astrocytes in many brain regions, particularly by focusing on intracellular changes in astrocytes and their interactions with neurons at the molecular and neural circuit levels.

Keywords: GFAP; astrocyte; behavior; chemogenetics; neural circuit; optogenetics.

Figure 1

The molecular mechanism underlying astrocytic regulation of neural activity in brain regions. The detailed explanations and references can be found from the text. AA, arachidonic acid; AgRP, agouti-related peptide; AMPAR, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors; AQP4, aquaporin 4; ATP, adenosine triphosphate; Best1, bestrophin 1; Cx43, connexin 43; DAO, diamine oxidase; EET, epoxyeicosatrienoic acid; GABA, γ-aminobutyric acid; GAT-3, GABA transporter type 3; GLT-1, glutamate transporter 1; IL-1, interleukin-1; LEPR, leptin receptor; MAOB, monoamine oxidase B; MSN, medium spiny neuron; PLC, phospholipase C; TC neuron, thalamocortical neuron; TSP-1, thrombospondin-1; VB, ventrobasal nucleus.

Figure 2

Schematic showing the intracellular signaling pathways in astrocytes and intercellular interactions between astrocytes and neurons. Separate pathways in a brain region are distinguished by numbering and alphabetical arrangement. Detailed explanations and references can be found in the text. AA, arachidonic acid; ADO, adenosine; AgRP, agouti-related peptide; AMPAR, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors; AQP4, aquaporin 4; ATP, adenosine triphosphate; Best1, bestrophin 1; CB, cerebellum; CTX, cortex; Cx43, connexin 43; DAO, diamine oxidase; EET, epoxyeicosatrienoic acid; GABA, γ-aminobutyric acid; GAT-3, GABA transporter type 3; GC, granule cell; GLT-1, glutamate transporter 1; HP, hippocampus; HY, hypothalamus; IL-1, interleukin-1; LV, lateral ventricle; M, medulla; MB, midbrain; MAOB, monoamine oxidase B; MSN, medium spiny neuron; NK1R, neurokinin 1 receptor; OB, olfactory bulb; P, pons; PLC, phospholipase C; Sp, spinal cord; STR, striatum; TC neuron, thalamocortical neuron; TH, thalamus; TSP-1, thrombospondin-1.