Friday, September 15, 2017

Research uncovers the neurons that drive thirst

6:18 AM    
That answer provides neurobiological support for

a seven-decades old psychological theory known as drive reduction, as least as it applies to thirst, but that was not exactly what graduate student William Allen, his advisor Liqun Luo, PhD, a professor of biology and Howard Hughes Medical Institute investigator, and colleagues set out to do. Instead, they wanted to better understand the nature of motivation—something neuroscientists who work with  and rats almost always manipulate using water.
"The vast majority of the experiments where you train animals to do something, you water restrict them and then give them water as a reward," said Luo, who is also a member of Stanford Bio-X and the Stanford Neurosciences Institute. In other words, if you make a mouse really thirsty, you can get it to do what you want by promising sips of water in exchange. The problem is, it doesn't work forever. If a mouse drinks enough water, it gets less thirsty, and one drop of water starts to be a lot less motivation.
Allen, Luo, and others from Luo's lab and that of Karl Deisseroth, MD, PhD, a professor of bioengineering and of psychiatry and behavioral sciences, wanted to find out how that worked. Their first step was to genetically modify mice using what they call TRAP2, a technique developed by co-first author and postdoctoral fellow Laura DeNardo, PhD, a member of the Luo lab, that lets researchers tag neurons actively firing in response to specific stimuli, then introduce further genetic modifications to the tagged neurons.