Well when I say neurotoxicity I am referring to the mass destruction that occurs to serotonin axons and receptors and the dysfunctional release of hormones that happens while your rolling and then stays that way for a little while after. This happens mostly in the hypothalamus. The part of your brain that controls the endocrine system (which controls hormones secretion). It also has a lot of other functions that involve memory and the sympathetic nervous system but there is no sense in getting into all that now.
The damage that gets done to your brain is temporary, it is always temporary. You brain sprouts new serotonin axons on a daily basis, but that doesn't mean that recovery is fast. Thousands need to be replaced; it's just a matter of time. The rule of thumb is that waiting a month is very beneficial, but it takes about three to fully recover. The more MDMA you do, the longer you have to wait. The more consistent your rolls become, the less time you have to heal, and the greater the damage. Damage is an ugly word yes, but it is really the only one available to describe what happens to your SERT system and possibly even dopamine system after rolling. MDMA is damaging! Yet, the brain will never stop fighting off that damage over time.
Heres the best way that you can help your brain along in the process: exercise. When you target large muscles, or do mass work outs your body releases BDNF. This is the growth hormone that helps your muscle grow, but it also influences your brain to sprout new axon quicker. You will still need to give your brain time to 're-wire', but it helps. You can try eating healthy do, get a lot of tryptophan into your diet: whole grains, turkey, other poultry, fish, cows milk, soy, eggs, spinach.... see a pattern?... eat healthy. Don't worry yourself too much about this, stress will only hold you back. You'll be fine soon enough.