Brav, I see you're still on the anti SSRI/TCA tirade.
SSRIs/TCAs as a whole tend to encourage an increase in brain volume, especially hippocampal hypertrophy, and tend to increase the amount of connections between neurons and the strength of connections between neurons.
We can't tunnel vision on what happens in a petri dish. Its much more helpful to look at whole brain experiments/studies. Just because there is some cytotoxicity/increased apoptosis of dorsal root ganglion cells at whatever concentration in vitro doesn't mean that that effect is appreciable to various other neuron types
in vivo. It could be especially irrelevant with regards to the pathology that the drugs are attempting to treat.
With regards to the study, here is a study showing that amitriptyline can be protective of dorsal root ganglion cells if the dosage doesn't get too high
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863790/
"
Amitriptyline stimulated DRG neuronal development in dose-dependent manner, but exerted toxic effect at concentrations higher than 10?M.
AM reduced lidocaine-induced DRG neurodegeneration by regenerating neurites and growth cones."
Dosage makes the cure or the poison. See this graph and the stains.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863790/figure/F1/
Keep in mind that the dosage/concentration can be pushed incredibly high in vitro to produce effects that will never been seen in vivo.