Host: The Japanese Pharmacological Society
Name : The 96th Annual Meeting of the Japanese Pharmacological Society
Number : 96
Location : [in Japanese]
Date : November 30, 2022 - December 03, 2022
The brain is equipped with an unique water system consisting of blood-brain barrier, cerebrospinal fluid, and astrocyte AQP4. The water environment in the brain is supposed to be essential for the highly developed information processing by neurons, but the crosstalk between water and neuron is still to be elucidated. We had reported that water influx mediated by AQP4 induces ATP release and subsequent increase of extracellular adenosine, which modulates neuronal activities, as well as blood flow and immune cells. Furthermore, we are finding that the adenosine derived from astrocytes affects dopamine neurotransmission and is associated with psychiatric disorders. Depressive behavior is affected in AQP4 knockout mice, which shows altered adenosine release, adenosine receptor expression and adenosine-dependent modulations of dopamine neurotransmission. Since AQP4 localizes to the astrocytic endfeet along blood vessels, these data suggest that the water flow from the bloodstream to brain parenchyma influences neural activities. And this water flow is likely accelerated by the nutrient uptake during neuronal activities, because astrocyte active transport is the exclusive gate to the brain parenchyma. We propose water system as an emerging clue for understanding brain functions.
