Article Figures & Data
Figures
- Figure 1.
METH enhances the differentiation of immature DG neurons. A, Representative confocal images exhibiting the different phenotypes of immature GFP+ DGCs. Open arrows, GFP+/DCX+ cells; closed arrows, GFP+/DCX+/NeuN+; arrowheads, GFP+/NeuN+. Scale bar, 50 µm. B, Bar graph illustrating the effect of METH in GFP+ cell phenotype. Data are expressed as a percentage of GFP+ cells ± SEM from four horizontal slices/animal of at least five animals per condition. ***p < 0.001, significantly different from saline using Mann–Whitney post hoc test. C–I, Current-clamp traces showing that GFP+ cells exhibit different AP firing profile patterns identified as group 1, 2, 3, and mature cells (C, E, G, I), respectively, and the respective phenotype characterization (D, F, H, and J). Cells were analyzed from at least three mice. Scale bar, 5 µm.
- Figure 2.
METH effects on LTP in differentiating GFP+ neurons and in mature DGCs. A, The diagram on the left illustrates the recording configuration. Middle, Representative time courses of EPSCs in both saline-injected (open symbols) and METH-injected (filled symbols) mice of group 2 GFP+ cells. Insets, Representative 60 traces (gray lines) and their average (black lines) before (1) and ∼40 min after (2) TBS (arrow). B, Population time course of group 2 DGC plasticity. C, LTP magnitude assessed after ∼40 min (2) normalized to baseline (1) in group 2 DG neurons. D–F, As in A–C, but for group 3 cells. G–I, as in A–C and D–F, but for mature, GFP− DGCs. Data are expressed as the mean ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different from baseline using the Mann–Whitney post hoc test. §p < 0.05, §§p < 0.01, significantly different from saline, using the Mann–Whitney post hoc test.
- Figure 3.
DG immature neurons exhibit different morphologies. A, Example micrographs of neurobiotin-filled DGCs of all groups (left) and their digital reconstructions (right). B, C, Bar graphs representing the total dendritic length (B) and the number of dendritic terminals (C) of GFP+ and mature DGCs, showing no effect of METH. Data are expressed as the mean ± SEM from at least four mice. *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different using the Kruskal–Wallis test followed by Dunn’s post hoc test. G1, Group 1 GFP+ cells; G2, group 2 GFP+ cells; G3, group 3 GFP+ cells; M, mature DGCs.
- Figure 4.
METH effects on spine areas in immature and mature DGCs. A, Representative confocal images of dendritic spines of group 2 and 3 GFP+ cells and mature neurons. Scale bar, 5 µm. B, Bar graph depicting spine density in immature and mature DGCs. C–E, Distribution graph of spine area quantified from group 2 (C) as well as in group 3 (D) GFP+ cells and mature DGCs (E). *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different using the Kruskal–Wallis test followed by Dunn’s post hoc test. Cumulative distributions were compared using Kolmogorov–Smirnov test. Scale bar, 1 µm.
Tables
Group 1 Group 2 Group 3 Saline METH Saline METH Saline METH AP peak (mV)* −0.97 ± 1.70 −0.72 ± 4.28 34.59 ± 2.26 40.95 ± 1.70 45.27 ± 1.72 46.18 ± 2.50 AP amplitude (mV)* 29.38 ± 3.10 30.25 ± 5.99 80.57 ± 3.86 85.83 ± 2.81 95.24 ± 1.47 94.43 ± 2.94 AP area (mV · ms) 78.71 ± 3.63 75.44 ± 6.68 91.27 ± 5.42 84.50 ± 7.36 92.91 ± 2.97 85.47 ± 3.84 Half-width (ms)* 3.38 ± 0.45 3.35 ± 0.69 0.98 ± 0.10 0.79 ± 0.06 0.85 ± 0.04 0.79 ± 0.05 Cm (pF)* 21.66 ± 0.77 19.96 ± 1.18 40.02 ± 3.21 42.39 ± 7.32 56.00 ± 3.13 49.96 ± 3.22 Rin (GΩ)* 2.32 ± 0.16 2.35 ± 0.18 0.68 ± 0.11 0.92 ± 0.15 0.38 ± 0.03 0.36 ± 0.03 RMP (mV)* −38.00 ± 1.76 −36.25 ± 4.09 −62.01 ± 3.39 −58.79 ± 2.87 −68.17 ± 1.20 −69.21 ± 1.53 Values are given as the mean ± SEM. METH induced no effect in all parameters analyzed. Cm, membrane capacitance; Rin, input resistance; RMP, resting membrane potential.
*Significantly different, using Kruskal–Wallis test followed by Dunn’s post hoc test or Bonferroni’s post hoc test. Asterisks correspond to statistical significance (p < 0.05) between group 1 and group 2 GFP+ DGCs, and between group 2 and group 3 GFP+ DGCs in saline conditions.
In this issue
