Brief Answer:
Both proteins and nerve signals are important.

Detailed Answer:
Hi,

Thank you for posting your query.

Brain controls various parts of body through nerve signals controlled by various neurotransmitters.

In addition, pituitary glad located in brain produces proteins called as hormones, which control several parts of body such as thyroid, sugar, sex functions, growth, etc.

So, it is a combination of both proteins as well as nerve signals, which are important.

I hope my reply has helped you.

I would be pleased to answer, if you have any follow up queries or if you require any further information.
     
Best wishes,
Dr Sudhir Kumar MD (Internal Medicine), DM (Neurology) XXXXXXX Consultant Neurologist
Apollo Hospitals, XXXXXXX
For DIRECT QUERY to me: http://bit.ly/Dr-Sudhir-kumar
My blog: http://bestneurodoctor.blogspot.com/

---