Colloids as Mobile Substrates for the Implantation and Integration of Differentiated Neurons into the Mammalian Brain
Figure 4
Functional integration of transplanted neurons.
a) Live confocal imaging of calcium response in a hippocampal slice containing a transplanted LiGluR6 neuron expressing GFP b) and labeled with a calcium indicator, Rhod-2 c). Panel d) shows an overlay of both channels. Scale bar = 100 µm. LiGluR6 cell was stimulated by short exposure to 390nm light for a short period of time and we recorded the calcium response of the surrounding neurons. a) shows calcium variation of individual cells (single pixel) after binning (3x3) and subtraction of the fluorescence background. Response was color-coded using a rainbow scale. Corresponding fluorescence intensity changes during UV stimulation are shown in panel e). All neurons in the slice responded to the stimulation indicating that the transplanted cell has made functional connections with the surrounding neurons. For 6 neurons distributed above (labeled a b c) and below (labeled 1 2 3) the transplanted cell we calculated ΔF/F for seven UV stimulations f). ΔF/F of the LiGluR6 neuron remains around 30% (+/−2.5%). (abc) neurons have, in average, higher ΔF/F than the stimulated neurons with significant variations from one exposure to the next, while (1 2 3) neurons have, in average, a smaller ΔF/F.