Figure 1. Transient shift in TC synaptic strength from CT and ET equivalent to CT dominant one day after NE.

(A) Schematic illustration of stereotaxic injections of retrograde microspheres to label L5 extratelencephalic neurons (ETs, green), and viral vectors (AAVs) for expression of ChR2 in thalamocortical (TC) inputs and tdTomato in L6 corticothalamic neurons (CTs, red) in Ntsr1-Cre mice.

(B) Schematic illustration of slice electrophysiology experiment involving photostimulation of ChR2 expressing TC afferents and simultaneous (dual) recording from an ET (green) and a CT (red).

(C) Images in 4X magnification showing the extent of ACtx area in bright-field (left), green-labeled ETs and TC axons (middle) and red-labeled CTs

(D) Average CT/ET EPSC ratio after optogenetically stimulating thalamic L5–6 input 1d and 7d after SE and NE. (1d SE: 18 cells/6 mice; 1d NE: 26 cells/9 mice; 7d SE: 10 cells/6 mice; 7d NE: 10 cells/6 mice). Asterisks indicate significant differences (***p<0.001, two-way ANOVA and Bonferroni correction for multiple comparisons).

(E) Representative traces of EPSCs in dual recordings from both CT (solid line) and ET (dotted line) neurons evoked by maximal photostimulation of L5–6 thalamocortical inputs in 1d SE (E₁) and 1d NE (E₂); 7d SE (E₃) and 7d NE (E₄). Different colored traces represent different pairs of simultaneously recorded CTs and ETs.

Detailed statistical values are listed in Table 1.