Since there's deep brain stimulation that stimulate neurons, is there deep brain "inhibition" that inhibits neurons?

Yes: It is interesting that it is called " stimulation", in fact it inhibits the neuron depending upon the degree of stimulation applied. For example the involuntary movement of Parkinson's disease are controlled by "inhibition". Similarly " interstim" is the technique to stimulate to cause inhibition of bladder contractions to cure loss of urinaty control. The entire process is well understood.