Figure 4
(a) Logarithmic VRMS amplitude of Tibialis Anterior (TA) motor activity in response to 473 nm, 105 mW/mm2 transdermal illumination of the proximal tibia for 4 s at 5 Hz and 10 ms PW for rats treated with slow release tacrolimus pellet compared to rats treated with placebo pellet. (b) Logarithmic minimum transdermal illumination power needed to elicit transdermal EMG spikes from TA for tacrolimus-treated and placebo-treated rats: VRMS spike threshold set to 2.45 µV, which was empirically determined to be the max noise level of recordings. (c) Ipsilateral to contralateral side of injection muscle weight ratio at the time of euthanasia between tacrolimus and placebo rats for both the anterior and posterior compartment muscle groups, representing primarily the TA and Gastrocnemius muscles respectively (n = 8 for tacrolimus, 9 for placebo group). Tacrolimus rats #3 and #7 (which had lost expression at time of euthanasia), and placebo rat #4 (which maintained expression at time of euthanasia) were excluded, as shown in Supplemental Figures. P = 3E-6 for anterior compartment and P = 0.23 for posterior compartment. (d) Normalized ELISA comparing plasma antibodies against ChR2(H134R)-EYFP for WT rats at 6 weeks post injection (n = 10) and 12 weeks post injection (all others, n = 10). P = 5E-5 for 6 vs 12 week comparison. P = 3E-5 for tacrolimus vs. placebo comparison at 12 weeks. In addition to being included in their respective groups, rat #3 in tacrolimus group and rat #4 in placebo group are also shown separately as they are outliers in their respective groups. (e) ChR2-EYFP+ axon counts as percentage of total axons in tibial nerve (t.n.) and common peroneal nerve (c.p.n.) of tacrolimus and placebo rats (nTacrolimus = 8, nPlacebo = 9): Pt.n. = 5E-3; Pc.p.n. = 1E-3. Tacrolimus rats #3 and #7 (which had lost expression at time of euthanasia), and placebo rat #4 (which maintained expression at time of euthanasia) were excluded. (f) Sciatic nerve cross sections of representative Rag2−/− rat (left) and WT rat (right) labeled for ChR2-EYFP (green) and DAPI (blue). Scale barleft,right = 120 µm, Scale barcenter = 20 µm. Experiment repeated 7 times with similar results.
