PT  - JOURNAL ARTICLE
AU  - Alex Plata
AU  - Alexander Popov
AU  - Pavel Denisov
AU  - Maxim Bychkov
AU  - Alexey Brazhe
AU  - Ekaterina Lyukmanova
AU  - Natalia Lazareva
AU  - Alexei Verkhratsky
AU  - Alexey Semyanov
TI  - An astrocytic basis of caloric restriction action on the brain plasticity
AID  - 10.1101/625871
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 625871
4099  - http://biorxiv.org/content/early/2019/05/02/625871.short
4100  - http://biorxiv.org/content/early/2019/05/02/625871.full
AB  - One month of calorically restricted diet (CR) induced morphological plasticity of astrocytes in the stratum (str.) radiatum of hippocampal CA1 in three-months old mice: the volume fraction of distal perisynaptic astrocytic processes increased whereas the number of gap-junction coupled astrocytes decreased. The uncoupling was not associated with a decrease in the expression of connexin 43. Uncoupling and morphological remodeling affected spontaneous Ca2+ activity in the astrocytic network: Ca2+ events became longer, whereas their spread was reduced. The change in the pattern of astrocytic Ca2+ activity may increase the spatial resolution of the information encoding in the astroglial network. Consistent with expanded synaptic enwrapping by the astroglial processes, the spillover of synaptically released K+ and glutamate was diminished after CR. However, no significant changes in the expression of astrocytic glutamate transporter (GLT-1/EAAT2) were observed, although the level of glutamine synthetase was decreased. Glutamate uptake is known to regulate the synaptic plasticity. Indeed, the magnitude of long-term potentiation (LTP) in the glutamatergic CA3-CA1 synapses was significantly enhanced after CR. Our findings highlight an astroglial basis for improved learning and memory reported in various species subjected to CR.