Optogenetic Stimulation of Vagal Efferent Activity Improves Exercise Capacity and Ejection Fraction in MI-Induced Heart Failure in Rats
(A) Representative sections of the left ventricle (LV) from a sham-operated animal (sham/sham vagus nerve stimulation [VNS] group), an animal with MI expressing enhanced green fluorescent protein (eGFP) in the DVMN after 4 weeks of sham-stimulation (post-MI/shamVNS group), and an animal with MI expressing ChiEFtdTomato in the DVMN after 4 weeks of efferent vagus stimulation using light (post-MI/optoVNS group). Summary data illustrate infarct sizes determined by computerized planimetry of LV sections of rats transduced to express eGFP or ChiEFtdTomato by the DVMN neurons after 4 weeks of light stimulation commencing 2 days after the occlusion of the left anterior descending artery (Student’s t-test). (B and C) Summary data illustrating the exercise capacity and LV ejection fraction of rats transduced to express eGFP or ChiEFtdTomato by the DVMN neurons after 4 weeks of light stimulation commencing 2 days after the occlusion of the left anterior descending artery or sham surgery. Data are presented as individual values and mean ± SEM. Comparisons are made using 2-way analysis of variance followed by Sidak’s correction for multiple comparisons. Abbreviations as in Figure 1.