The neurobiological mechanisms underlying depression are not fully understood. Only a few previous studies have used validated counting methods to test how animal paradigms of depression affect adult hippocampal neurogenesis and whether antidepressant therapy can counteract possible changes in an animal model.
Thus, in this study we applied methods that are state of the art in regard to stereological cell counting methods to estimate the total number of new neurons made in the hippocampus after electroconvulsive stimulation.
Using a validated rat model of depression (chronic stress) in combination with a clinically relevant schedule of electroconvulsive stimulation, we found no change in the number of newly formed neurons in depressive-like rats, whereas electroconvulsive stimulation increased neurogenesis by 220%. Also estimated were the total number of neurons and the volume of the hippocampus. Neither of the treatments induced changes in these parameters.