nerve center

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A group of closely connected nerve cells that perform a specific function.
• noun A source of power or control.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy A point at which nerves come together for the processing of information.
• noun By extension, a physical location in a business, organization, or agency where information procured from different sources is brought together to be considered and acted upon by decision-makers.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a center that provides information and control
• noun a cluster of nerve cells governing a specific bodily process