Figure 5
From: Evidence for newly generated interneurons in the basolateral amygdala of adult mice
Functional properties of new neurons in the basolateral amygdala (BLA) using retrovirus labeling and lineage tracing. (a) A schematic illustrating bilateral injections of green fluorescent protein (GFP)-retrovirus in the BLA of 8-week-old C57BL/6 J mice. (b) Example GFP+ neurons (green) in the BLA recovered from whole-cell patch-clamp recordings and filled with biocytin (red). Note the presence of a doublet. Nuclei are stained with DAPI (blue). Scale bar, 50 μm (c) Whole-cell patch-clamp recordings from one GFP+ cell of the doublet showing (i) a train of action potentials induced by a +190 pA current injection, (ii) an example of spontaneous excitatory potential recording while injecting current steps from −60 to +80 pA, and (iii) an example trace of sEPSCs recorded while holding the cell at −60 mV. (d) Schematic showing tamoxifen injection in Ascl1CreERT2; CAGfloxStop-tdTomato mice. (e) An example of a tdTom+ cell (red) in the BLA, 4 weeks after the last tamoxifen injection, which was recovered with biocytin (green) following whole-cell patch-clamp recordings. Scale bar, 50 μm (f) An example of whole-cell patch-clamp recordings of a tdTom+ cell at 4 weeks post-tamoxifen showing (i) a train of action potentials induced by +190 pA current injection, (ii) an example trace of sEPSCs recorded while holding the cell at −60 mV, and (iii) an example of a spontaneous excitatory potential recording while injecting current steps from −60 to +20 pA. (g) An example of whole-cell patch-clamp recordings from a tdTom+ cell at 8 weeks post-tamoxifen showing (i) a train of action potentials induced by +240 pA current injection, (ii) an example trace of sEPSCs recorded while holding the cell at −60 mV, and (iii) an example of a spontaneous excitatory potential recording while injecting current steps from −60 to +120 pA. (h) Graph showing the input resistances of recorded cells in the BLA. Note that the tdTom+ cells at 4 weeks have higher input resistance than the input resistances of principal neurons (n=5, *P<0.05), retrovirus-GFP+ cells at 7–8 weeks (n=6, **P<0.01), and tdTom+ cells at 8 weeks (n=6, **P<0.01). (i) Graph showing action potential half-widths from recorded cells within the BLA. Principal neurons have a half-width (n=5) that is slower than the half-widths of tdTom+ cells at 4 weeks (n=5, **P<0.01), GFP+ cells at 7–8 weeks (n=6, *P<0.05), and tdTom+ cells at 8 weeks (n=5, ***P<0.001).
