Fig. 1
Identification of IC and HC astrocytes. a, d: Semischematic drawings of coronal sections containing the central nucleus of the IC together with the lateral lemniscal tract (LL) (A) and the CA1 region of the HC (CA: cornu ammonis; GD: gyrus dentatus; SO: stratum oriens; SP: stratum pyramidale; SR: stratum radiatum; SLM: stratum lacunosum moleculare). b, e: SR101-labeled cells (astrocytes) were widely distributed within the IC (b) and the HC (e). They exhibited a small soma and were highly branched (insets in b and e; scale bar: 10 μm). c, f: Astrocytes were clamped to EH = −85 mV and were stepwise hyper- and depolarized from −150 mV to +50 mV, with 10 mV increments. Membrane currents were recorded (top) and leak currents were subtracted (p/4; bottom). Non-passive astrocytes (nPA) expressed time- and voltage-dependent outward currents (c1, f1), whereas passive astrocytes (PA) lacked these currents (c2, f2). About 2/3 of IC astrocytes were passive (c3), whereas it was the opposite in the HC (f3). n represents the number of recorded cells