The basic functional units of the nervous system are

Alzheimer's disease

Parkinson's disease

Nicotine

Alcohol

LSD

A.

Depressant causing impaired judgment and possible liver damage with long term use

B.

Results in feelings of confidence that wear off quickly

C.

Increases risks for most cancers

D.

Progressive disorder resulting in tremors and uncontrolled movements

E.

A fungal derivative causing hallucinations and dangerous actions

F.

Progressive mental deterioration