Which of the following increases on Electroconvulsive therapy

Various change of neurotransmitters happen due to giving of ECT , one of the main change is the level of serotonin, dopamine and nor adrenaline. But in recent advances in functional imaging one of the most researched and evidence base if for the recent advances in neurobiology of electro convulsive therapy that too in the change of BDNF in the brain that is said to be responsibe for reduction of suicidal ideas in depressed patients. Ref.Kaplon and sadock, synopsis of psychiatry, 11 th edition, pg no. 1066