A woman with major depressive disorder underwent electroconvulsive therapy (ECT). Which of the following increases on ECT?

Electroconvulsive therapy (ECT) also increases the expression of brain-derived neurotrophic factor and its receptor (tyrosine kinase receptor B) in hippocampus and dentate gyrus, a process associated with neurogenesis and increased neural plasticity. Ref: Principles and Practice of Psychopharmacotherapy By Philip G. Janicak, M.D., Stephen R. Marder, M.D., Mani N. Pavuluri, 2011, Page 317.