Looks like a fungal infection of neural synapse.
The black on cray certainly makes this quite off putting, but the creeping infection being that sickly yellow really drives home the sense of wrongness.
I am curious if the background being grey is better then black, but considering how tightly the brain is packed, it makes sense.
I almost think the fungus sorting the neurotransmitter between two would be more horrifying, but most people don't what that looks like at a glance, so this makes sense in terms of accessibility.
Thanks for making this.