Astroglial adrenoreceptors modulate synaptic transmission and contextual fear memory formation in dentate gyrus

Somatostatin interneurons inhibit excitatory transmission mediated by astrocytic GABAB and presynaptic GABAB and adenosine A1 receptors in the hippocampus

“…Two weeks following viral injection into the hippocampus, we checked the expression of GCaMP6f with immunohistochemistry. Consistent with our previous report (Shen et al, 2021), we observed that the astrocytic specific marker glial fibrillary acidic protein (GFAP) was co-localized with GFP (GCaMP6f) Figure 5c,d). We also found that when GABA B Rs were blocked by CGP55845, the residual calcium elevations in astrocytes were sensitive to the GAT-3 blocker SNAP-5114 (CGP55845 + SNAP-5114: n = 15 slices from 7 mice; baseline, −0.03 ± 0.6 ΔF/F; light_on, −0.3 ± 1.2 ΔF/F; p = 0.8, two-tailed paired t-test; Figure 5g,h), consistent with previous reports that calcium responses caused by SOM-INs activation are mediated by GABA B Rs and GAT-3 activation (Matos et al, 2018).…”

“…Stereotactic virus injection was conducted as described previously (Shen et al, 2021). Briefly, the 2‐month‐old mouse was anesthetized by intraperitoneal injection with 50 mg/kg sodium pentobarbital, fixed to a stereotaxic apparatus by blunt ear bars, and the body temperature was maintained at around 37°C by a feedback‐controlled heating blanket.…”

“…After light stimulation, images were acquired for 20 s at 1 Hz in frame mode (100 ms per frame). The Ca 2+ signal analysis was described previously (Nikolic et al, 2018; Shen et al, 2017; Shen et al, 2021). Briefly, Ca 2+ signals were analyzed in ROIs with Time Series Analyzer V3 of ImageJ software.…”

“…In turn, Ca 2+ transients trigger the release of various neuroactive substances (termed gliotransmitter), such as ATP/adenosine (Bijelic et al, 2020;Jackson et al, 2017;Li et al, 2020;Matos et al, 2018;Nikolic et al, 2018;Serrano et al, 2006;Shen et al, 2017), glutamate (Angulo et al, 2004;Nikolic et al, 2018;Shen et al, 2017;Shen et al, 2021), D-serine (Adamsky et al, 2018;Henneberger et al, 2010;Panatier et al, 2006;Robin et al, 2018;Yang et al, 2003), and GABA (Kozlov et al, 2006;Le Meur et al, 2012) that bind to pre-or post-synaptic receptors and modulate synaptic transmission and neuronal excitability.…”

“…Astrocytes express a large variety of membrane receptors, which endow them with the ability to sense molecules released from neurons and glia and eventually generate Ca 2+ transients in the cytoplasm of the astrocyte (Bazargani & Attwell, 2016; Khakh & McCarthy, 2015; Verkhratsky et al, 2019; Volterra et al, 2014). In turn, Ca 2+ transients trigger the release of various neuroactive substances (termed gliotransmitter), such as ATP/adenosine (Bijelic et al, 2020; Jackson et al, 2017; Li et al, 2020; Matos et al, 2018; Nikolic et al, 2018; Serrano et al, 2006; Shen et al, 2017), glutamate (Angulo et al, 2004; Nikolic et al, 2018; Shen et al, 2017; Shen et al, 2021), D‐serine (Adamsky et al, 2018; Henneberger et al, 2010; Panatier et al, 2006; Robin et al, 2018; Yang et al, 2003), and GABA (Kozlov et al, 2006; Le Meur et al, 2012) that bind to pre‐or post‐synaptic receptors and modulate synaptic transmission and neuronal excitability.…”