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Updated: May 23, 2026
10:19
Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo
Published on: March 31, 2016
Wakefulness affects synaptic and network activity by increasing extracellular astrocyte-derived adenosine
L Ian Schmitt1, Robert E Sims, Nicholas Dale
1Department of Neuroscience, Tufts University Medical School, Boston, MA 02111, USA.
Summary
Wakefulness increases extracellular adenosine levels in the brain, impacting memory and sleep. This increase, mediated by astrocytes via gliotransmission, is crucial for regulating brain activity during wakefulness.
Area of Science:
- Neuroscience
- Sleep Science
- Astrocyte Biology
Background:
- Sleep loss impairs hippocampal memory and increases sleep drive.
- Adenosine A1 receptors (adorA1Rs) and astrocyte-derived adenosine are implicated in sleep homeostasis and memory.
- Previous research has not confirmed if extracellular adenosine levels rise with wakefulness.
Purpose of the Study:
- To investigate if extracellular adenosine levels increase during wakefulness.
- To determine the role of astrocyte gliotransmission in wakefulness-dependent adenosine changes.
- To examine the impact of these changes on synaptic and network activity.
Main Methods:
- Utilized mice (Mus musculus) to study wakefulness effects.
- Employed direct biosensor measurements to quantify extracellular adenosine.
- Genetically inhibited astrocyte gliotransmission to assess its role.
Main Results:
- Extracellular adenosine concentration significantly increased during normal wakefulness and sleep deprivation.
- Increased adenosine levels modulated synaptic transmission in the hippocampus and cortical network activity.
- Inhibiting gliotransmission blocked the adenosine increase and wakefulness-dependent regulatory changes.
Conclusions:
- Wakefulness elevates extracellular adenosine levels in the hippocampus.
- This adenosine increase is dependent on transmitter release from astrocytes (gliotransmission).
- Astrocyte-derived adenosine plays a key role in regulating brain function during wakefulness and sleep loss.
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