Fig. 7

The global calcium signals in the ACC neurons of tree shrew. a Representative two-photon fluorescent photomicrograph of a patched pyramidal neuron loaded by Alexa 594 and Cal-520 in the ACC of tree shrew. Blue dashed circle indicated the scanned area on soma. b Injection of currents induced action potentials (APs) and related Ca²⁺ signals. Upper: representative traces of APs evoked by injection of 40 pA (50 s) current; Bottom: related waveforms of fluorescence changes (ΔF/F) of global calcium signals. c Calcium signals were increased in a stimulation ntensity dependent manner in tree shrew and mouse. Left: representative waveforms of fluorescence changes (ΔF/F) of Ca²⁺ signals evoked by injection of 100 pA (400 ms) current in tree shrew and mouse. Right: statistical data of stimulation intensity dependent Ca²⁺ signals in tree shrew (n = 6 neurons/3 tree shrews) and mouse (n = 7 neurons/3 mice). d Calcium signals were increased in a frequency dependent manner in tree shrew and mouse. Left: representative waveforms of fluorescence changes (ΔF/F) of Ca²⁺ signals evoked by five APs at 50 Hz in tree shrew and mouse. Right: statistical data of frequency dependent Ca²⁺ signals in tree shrew (n = 5 neurons/3 tree shrews) and mouse (n = 5 neurons/3 mice). Ca²⁺ signals (ΔF/F) were normalized to control values. *P < 0.05, error bars indicated SEM