View Full Version : Genes, the brain, and behavior

05-31-13, 07:39 PM
In her first talk, Cori Bargmann explains how individual genes can affect the brain and behavior. Humans are complex creatures, but as many as 99% of our genes are shared with simpler organisms. By focusing on the genes for a family of proteins found in many organisms, the G protein-coupled receptors, Bargmann illustrates that mutations in a single gene can cause significant behavioral changes in organisms as diverse as nematodes, dogs and humans. In Part 2, Bargmann presents work from her own lab in which the olfactory system in C. elegans was used to dissect the role of genes on behavior. She shows us how it was possible to map the neuronal circuits that modulate worm behavior in response to different odors.

Dr. Bargmann points out at the beginning how the heritability of disorders (including autism, but, unfortunately, not ADHD) indicates their genetic origins. The first 11 minutes are a good overview of not only the relationship between genes and the brain, but also of how stimuli are produced externally and internally. After that, she focuses on a much more measurable neuron response, reaction to odor. I would still recommend watching that part, because it is relevant as an example of behaviors that have a genetic basis that have led researchers to explore more subtle behaviors as potentially having genetic origins as well. She continues to present information about innate behaviors, and environmental responses - the sleep cycle being something that can be tested for both. In fruit flies, a single gene plays a key role in circadian rhythm, but molecular activity influences gene expression over a very short period of time. Humans have the same type of regulation - and this will affect our behaviors, deep in the hypothalamus. This led to the discovery of the gene that regulates the chemical processing that leads to narcolepsy.

At this point, about 29 minutes in, she has a slide illustrating how neurons communicate, specific to neuropeptides, but it is also a useful explanation of the chemical interactions in synapses.

Following this, she begins to explore different social behaviors among different species, and brings up research that shows the influence of neuropeptides in these behaviors. The genes exist in the two species of voles that were subjects, but were expressed in different sections of the brain - a point I feel is important, since gene expression is a challenging concept. This is a good illustration of how the location and timing of gene expression is essential to what gene expression can actually do.

If you can watch the entire 38 minutes, there is a second part, as well. However, this is a good amount to digest on its own.

05-31-13, 07:48 PM
Who knew worms can smell? I want to listen to this, but the timing isn't
good right now. Maybe tomorrow.