Abstract
Locus coeruleus neurons innervate multiple brain regions. These neurons release noradrenaline through their axonal varicosities into the extracllular spac through synaptic and volume transmission during states of arousal. The extracllular spac is a channel that surrounds brain clls, facilitating diffusion-mediated transport of signaling molecules, ions, and drugs. Distal astrocytic procsses expressing β-adrenergic receptors are targets of noradrenaline. In this review, we discuss work in cortical tissue indicating that β-adrenergic agonist, isoproterenol, expands astrocytic procsses. Isoproterenol-driven increase in volume of astrocytic procsses contributes partially to decrease in the extracllular spac volume from 22% to 18%. Decrease in the extracllular spac volume suggests increased concntration of ions, neurotransmitters, and neuromodulators diffusing in the extracllular spac, which, in turn, facilitates neuronal signaling during noradrenaline release in cortex.
Original language | English (US) |
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Title of host publication | Noradrenergic Signaling and Astroglia |
Publisher | Elsevier Inc. |
Pages | 241-255 |
Number of pages | 15 |
ISBN (Electronic) | 9780128134269 |
ISBN (Print) | 9780128050880 |
DOIs | |
State | Published - Jan 1 2017 |
Keywords
- Astrocytes
- Diffusion
- Electron microscopy
- Extracllular spac
- Noradrenergic system
- Real-time iontophoretic (RTI) method
- Sleep-wake cycle
- Tortuosity
- Volume fraction
- Volume transmission
ASJC Scopus subject areas
- General Neuroscience