Figure 5.

Co-cultures of human primary neurons and hdINs at 35 DIV demonstrate afferent synaptic connections from the primary neurons to the hdINs. Immunohistochemistry of co-cultures of hdINs and human primary neurons used for electrophysiological analysis at 35 DIV. Some of the recorded neurons (biocytin +, B and D) were also hdINs mCherry + (white arrows, A and C), and some were mCherry-, indicating that the latter were primary neurons (yellow arrows, C–D). (E, F) The ratio of mCherry + /MAP2 + cells to human primary neurons mCherry-/MAP2 +. (G, H) Human primary neurons were mostly glutamatergic (KGA +, G) and very few GABAergic (GABA +, H). (I) Spontaneous synaptic currents in whole-cell voltage-clamp mode showing afferent connections to the hdINs at 35 DIV. Some of the events disappeared when NBQX and AP5 where applied (right). (J, K) Cumulative probability curves comparing the events during baseline (green) and addition of the drugs (orange) for both amplitude (J, left) and inter-event interval (K, left). Distribution of the mean amplitude (J, right) and frequency (K, right) for spontaneous synaptic currents. Scale bar: 100 µm. Mean ± SEM. Kolmogorov–Smirnov test for cumulative distributions and Wilcoxon test for comparison of paired means (n = 5). Kolmogorov–Smirnov test: **p < .005.