Fig. 5

Development of functional properties in CTX0E16 neurons. a Representative image of Fluo-4 AM-loaded CTX0E16 neurons used for single cell Ca²⁺ imaging. b Representative time series of 18 neurons displaying spontaneous Ca²⁺ transients. Spontaneous activity was classified as a somatic calcium event greater than 5 % ΔF/F0: 38.0 ± 6.89 % cells displayed spontaneous activity over an 80-second period of imaging (n = 155 cells from 14 coverslips). c, d Representative traces of intracellular Ca²⁺ in responses to 50 mM KCl (c) or 1 μM tetrodotoxin (TTX) (d). e Resting membrane potential (Vm) recorded in current clamp progressively becomes more negative as CTX0E16 neurons become more mature (day of differentiation (DD) 29−DD 61); error bars represent SD. f Representative action potential recorded in voltage clamp in the cell attached configuration, recorded from DD 50 CTX0E16 neuron. g Representative voltage clamp recording at a holding potential of −70 mV in DD 36 CTX0E16 neurons. The downward deflections indicate the presence of AMPA receptor-mediated spontaneous excitatory postsynaptic currents (EPSCs). h Example of a spontaneous N-methyl-D-aspartate (NMDA) receptor-mediated EPSC recorded in voltage clamp at +40 mV from a DD 33 CTX0E16 neuron; n = 3–6 cells from at least three independent coverslips