The touch of a fly

Our sense of touch has an innate connection with our emotions. Gentle touches are soothing for not only us but also other animals. For example, classic experiments by psychologist Harry Harlow in the 1950s found that an infant monkey raised with two robots, one providing food and the other wearing soft cloth, spends more time cuddling with the cloth robot1. When scared, the infant monkey also goes to the cloth robot for protection. Clearly, there is a special pathway that guides touch sensation to the depths of animal instincts. Working out this pathway requires knowledge about the neural circuitry processing touch sensation.

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Tagging a snapshot of life with prions

“As you know, in most areas of science, there are long periods of beginning before we really make progress.” – Eric Kandel

In a typical maze experiment, a hungry rat enters a moderately complicated maze, in which it does its best to find a “reward room” with food. After some guesses, the rat finds its way, consumes the food, and is returned to the entrance of the maze. From then on, the rat makes fewer bad guesses and finds the food faster after each round. Eventually, it completely masters the maze layout and finds the perfect route every time. To explain this improvement, scientists have coined the term reward reinforcement, which essentially suggests that the reward that the rat collects at the end reinforces its correct choices, until it eventually learns a perfect route. This model may sound very simple, but is it?

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Oxytocin: sculpting the maternal brain

Humans have a lot in common with prairie voles—at least when it comes to mating. Unlike the vast majority of mammalian species, we often enter into monogamous pair bonds. A crucial molecule involved in determining this mating strategy is oxytocin. Popularly known as the “cuddle hormone,” oxytocin is a neuropeptide that plays an ancient role in orchestrating social and reproductive behaviors [1], and frequently makes headlines because of its ability to influence a variety of interesting behaviors [2]. Until recently, however, it has remained unclear how and where oxytocin is exerting its effects in the brain. Using modern experimental tools, neuroscientists are beginning to develop a more mechanistic understanding of how oxytocin affects specific circuits in the brain.

Chemical structure of oxytocin.

Chemical structure of oxytocin.

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