The Thirsty Fly Analysis

Tim Jenkins Brain Story 13 “The Thirsty Fly” Dr. Kroger Psy 375 11-16-16

In Weiner’s “The Thirsty Mind” article (2014), the neurostructures of a fruit fly were analyzed as it related to “thirst”. Kent Berridge has spent decades of his life devoted to the biological reward circuitry that exist. Berridge’s theory of rewards was broken down into 3 subcategories; liking, wanting and learning (Weiner, 2014). Different species have similar responses to a sweet taste: sticking their tongues out, which Berridge defines loosely as liking (Weiner, 2014). “Wanting” is the pursuit of what the organism likes; while the associations regarding their likes is learning (Weiner, 2014).

Berridge’s research has been received with varying levels of acceptance.

To accelerate the dehydration of the flies, the researchers put in a Drierite layer, which is used to pull moisture out of safes and closed spaces. After hours of being dehydrated, the flies were thoroughly thirsty and went “running” to the moisture. This rehydration served as ample reward to fire circuitry in the brain associated with rewards. There appears to be 130 neurons that release dopamine which feed signals to the mushroom body (similar to our hippocampus). These fire an “Ah water” signal. There are other similar yet distinct circuits for other things like sugar or even remembering the taste of water which is innate; it’s built in their antennae. This explains the “wanting” when the fly enters the wet tube after being thirsty. The “liking” is observed with the pickpocket 28 neurons telling the proboscis to react to the presence of sugar water. And the “learning” is when the fly remembers its choices when it was thirsty to get to the wet tube as it remembers the taste of water. The researchers are getting a finite glimpse into our own reward systems through flies; even at 2 neurons within the flies. This research has established the nuts and bolts of the fly’s brain. We can now make the flies lose control and become ravenously hungry or thirsty because we know their circuitry so well. These finding are about to be presented to President Obama as part of the BRAIN