Does the shape of our neurons define our behavior?

People have often said that the brain is the most com­plex thing in the uni­verse. Of course, a state­ment like that spurs heated debate, but it’s still an inter­esting con­cept. The human brain con­sists of 100 bil­lion neu­rons and sev­eral hun­dred tril­lion synapses, according to assis­tant pro­fessor of psy­chology Rebecca Shansky. In her Lab of Neu­roanatomy and Behavior, Shansky is studying the struc­ture of neu­rons and how com­mu­ni­ca­tion between them, among that com­plex net­work, drives behavior.

Our long term goal is demon­strate the real func­tional rel­e­vance of struc­tural dif­fer­ences between males and females with spe­cific rel­e­vance to fear,” she said. Appar­ently females are two times as likely to suffer from post trau­matic stress dis­order than males. Other odd dis­par­i­ties in the way we behave seems to indi­cate that there may be some inter­esting dif­fer­ences in the struc­tures of our neu­rons, which could inform better treat­ment strate­gies for behav­ioral dis­or­ders like PTSD. “Even though the symp­toms are the same among males and females, the under­lying neu­ro­bi­ology may be dif­ferent,” said Shansky.

She was recently awarded a $275,000 grant from the National Insti­tutes of Health to explore poten­tial dif­fer­ences in the brains of male and female rats. She will look at 100 male and 100 female rates (appar­ently ridicu­lously high num­bers for animal studies), choose the ones who show extremely high or low levels of fear and examine the neu­rons known to be involved in fear.

We’re trying to get a com­pre­hen­sive pro­file of resilience and vul­ner­a­bility,” she said. They will look at things like how many “spines” are sticking off of a vul­ner­able animal’s neu­rons com­pared to a resilient one. They’ll look at the shape of those spines — are they skinny or mushroom-​​like? — as well as the size of the entire neuron. “We’ll be looking for struc­tural cor­re­lates of behavior,” said Shansky.

Appar­ently only a small per­centage of people are sus­cep­tible to PTSD — most of us expe­ri­ence some­thing in our life­time that could cause trauma for one person but not another, such as a car acci­dent or the loss of a loved one. What makes people who do get PTSD spe­cial? What makes some vul­ner­able and others “super resilient”? These are all ques­tions Shansky hopes to answer eventually.

Every­thing changes your neu­rons. The brain is in con­stant flux,” she said. Thus, an already com­pli­cated system is con­stantly being changed and adapting by our expe­ri­ences. Per­haps the very shape of our neu­rons in the first place informs that process.