Fig. 7

Human adult cortex-derived slice cultures (hACtx) are viable and contain functional neurons and astrocytes up to 6 weeks. a–d Confocal images of hACtx slices prior to culture showing expression of Fox3 (a), GFAP (b), and Hoechst (c) by hACtx cells. Scale bar = 40 μm. e–h Orthogonal projections of confocal images showing expression of FOX3, SC121, and Hoechst by hACtx slices after 6 weeks in culture. Scale bar = 20 μm. i–l Synaptic connectivity between host neurons in non-grafted hACtx slice cultures. i Confocal image of hACtx organotypic slice showing an overview of hACtx cell labeling with TVA-GFP and subsequent tracing with ΔG-rabies virus. Labeled neurons were mCherry⁺/GFP_nuc ⁺ after tracing with ΔG-rabies virus (l, arrow ). Traced neurons were mCherry⁺/GFP_nuc ^– (l, arrowhead), indicating occurence of synaptic connections between adult neurons in the organotypic slice cultures. m–o Whole-cell patch-clamp recordings from SynI-RFP⁺ hACtx neurons. m Voltage traces illustrating the generation of APs during a 900 pA current step lasting 500 ms. n,o Current traces of the fast inward current peak (n) and the sustained outward current (o) activated by step depolarizations from a holding potential of –70 mV in the absence (black) and presence of 1 μM tetrodotoxin (TTX) (red, n) or 1 μM TTX and 10 mM tetraethylammonium (TEA) (blue, o). * Inward current peak (n) or sustained outward current (o)