I've experienced this on Mimosa as well, as far as i can remember never experienced this on Acacia, haven't tried Chali or Chacruna yet though. But i for one actually quite liked the Mimosa brain zaps, it felt good kinda, almost like it was resetting some of my neurochemistry or something, didn't happen all the time, just a few times, one night i was sitting outside and it was nice and cool, had a bottle of water sitting on the cool ground, went to take a sip, and when the water entered my mouth not only could i taste it/the minerals in it but i got some nice zaps at that moment. I used to be on anti-depressants, anti-psychotics, stimulants, mood stabilizers, the works, cut all that out in 2010 when i started smoking Cannabis regularly, and in 2012 i found Rue and Mimosa, took that for a good while and only encountered the zaps a few times, but it did feel like it was resetting some of my neurochemistry. Idk about being short on Serotonin, but i've felt since Aya that i'm good in Serotonin, in fact i may naturally have a bit too much Serotonin, but seem to be lacking a bit in Dopamine/Noradrenaline and started dosing Mucuna daily in 2017 for 3 years until this year i stopped taking it and ever since i feel i've stored up/replenished my body with Dopamine/Noradrenaline. But yeah haven't experimented with Aya since 2015, have had a few other Psychedelics since, but i've been on a break these last few years.
One kind of brain zap in particular though i've encountered on Aya was from Zinc Gluconate, it was very jarring, didn't feel good at all, unlike the Mimosa zaps.