How the Hen House Turns: Chicken Brains Are Not Simple

How the Hen House Turns: Chicken Brains Are Not Simple
Column by Carolyn A. (Cary) Neeper, Ph. D.

The human brain has been called the most complex object in the universe. It deserves that title because its 86 billion neurons each can have as many as 10,000 connections to other neurons.

Also, neurons are supported by at least three types of glial cells—astrocytes that provide oxygen and nutriens, oligodendrocytes that provide a myelin insulation, and microglia that act as nursemaids. Check out Science News Nov. 30, 2013.

By comparison, suns and galaxies are relatively simple, with billions of objects interacting with fewer nonlinear options. Biology trumps astrophysics in the complexity department.

Mouse brains have only 71 million neurons, so chickens probably don’t have too many more, or less.

The many types of neurons and glial cells are not alone in the brain. They are enmeshed in a complicated arrangement of fine connective tissue and fed by a vast network of blood vessels and hormones.

Recently, we have discovered that they can grow and invent needed pathways or replace damaged ones. In the 1990s my daughter did her master’s thesis showing that the neuronal growth hormone in rats spiked in those rats that spent nights running on exercise wheels.

That’s very interesting, but the point here is that brains, even small ones, are not simple and they are not all the same. Birds, at least scrub jays, have a special lump of brain tissue that remembers where thousands of peanuts are hidden by our front porch. An entertaining read is Colin Tudge’s “The Bird” at

Here’s another case in point. Though my Khaki Campbell ducks have WYSIWYG brains, (they can’t remember to go around the fence to exit the pen if the opening is not visible) they never forget that I’m the person who digs red worms for them or that the Hen House is where they are supposed to sleep when winter comes.

I suspect that evolution—selection working with the complex phenomenon of self-organization in the brain—has provided living creatures with a genius for finding and selecting good food and shelter. The brain’s complexity means that every one is unique.

Temple Grandin, in her new book, The Autistic Brain, ( emphasizes that every autistic child is an unique case to be treated with specific care and directions. They need intensive training in verbal skills in the early years, then job skills later.

Behavior patterns labeled “autism” present a continuum of  abilities and unique talents. Labels that categorize symptoms limit the imagination and endanger the treatment by those responsible for the care of individual lives. The key is to concentrate on children’s abilities, which can be extraordinary, not their dysfunctions.

Specialization is also true in the Hen House. Each type of bird has its own way of doing things, its own favorite food and its own peculiar bathing habit, as well as its own idea of who I am and what I’m good for.