Astrocyte- and NMDA receptor-dependent slow inward currents differently contribute to synaptic plasticity in an age-dependent manner in mouse and human neocortex

• Published in: Aging cell Vol. 22; no. 9; p. e13939
• Main Authors: Csemer, Andrea, Kovács, Adrienn, Maamrah, Baneen, Pocsai, Krisztina, Korpás, Kristóf, Klekner, Álmos, Szücs, Péter, Nánási, Péter P, Pál, Balázs
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.09.2023; John Wiley and Sons Inc
• Subjects: Aging; Electrophysiology; Glutamic acid receptors (ionotropic); N-Methyl-D-aspartic acid receptors; Neocortex; Synaptic plasticity; slow inward current; human brain; pyramidal cell; neocortex; aging; synaptic plasticity; NMDA receptor; astrocyte
• ISSN: 1474-9718; 1474-9726; 1474-9726
• DOI: 10.1111/acel.13939

Slow inward currents (SICs) are known as excitatory events of neurons elicited by astrocytic glutamate via activation of extrasynaptic NMDA receptors. By using slice electrophysiology, we tried to provide evidence that SICs can elicit synaptic plasticity. Age dependence of SICs and their impact on synaptic plasticity was also investigated in both on murine and human cortical slices. It was found that SICs can induce a moderate synaptic plasticity, with features similar to spike timing-dependent plasticity. Overall SIC activity showed a clear decline with aging in humans and completely disappeared above a cutoff age. In conclusion, while SICs contribute to a form of astrocyte-dependent synaptic plasticity both in mice and humans, this plasticity is differentially affected by aging. Thus, SICs are likely to play an important role in age-dependent physiological and pathological alterations of synaptic plasticity.