Breakthroughs, discoveries, and DIY tips sent every weekday. In a world first, scientists at the University of Utah have engineered fruit flies susceptible to cocaine addiction. But as strange as it sounds, there are potentially life-saving reasons for genetically altering the insects to crave the drug. The novel biological model could help addiction treatment therapies development and expedite research timelines. The findings are detailed in the Journal of Neuroscience.

The thalamus – a structure in the centre of the brain that relays information from the senses – may be responsible for sorting memories before they are stored long term, a study in mice suggests. Previously, the thalamus has been largely overlooked in research on memory processing. Priya Rajasethupathy at the Rockefeller University in New York and her colleagues studied the brain activity of dozens of mice navigating a virtual maze. When the mice's thalamus was stimulated while learning the maze, the animals were able to recall the routes they learned weeks later – by which point they would ordinarily have forgotten. The process of forming and storing memories involves multiple regions of the mammalian brain.

Motivation to learn new things and engage with life declines with age due to falling activity in a brain circuit that weighs costs and benefits, a study on mice suggested. US experts have been studying'striosomes' -- clusters of cells in the basal ganglia, a brain area linked to habit formation, movement control, emotion and addiction. They team found that striosomes are key to the decision making process when dealing with'approach-avoidance conflict' -- when a choice has both pros and cons. For example, one such thorny problem might be whether or not to take a new job that pays better, but would also call for a move away from family and friends. Working with mice, the researchers found that striosomal activity is correlated to the evaluation of costs and benefits -- but that this activity diminishes with age.

Zero is an extremely hard concept to understand. Quantities of things--whether they are bundles of fruit, communities of people, or blocks of wood for construction--are vital to our livelihood. But nothing, as far as the brain is concerned, is far different than something. Humans have had a hard time coming to terms with this concept. But our ability to grasp zero as a distinct numerical value is a vital part of modern mathematics, engineering, and technology.

In his experiment, Queen Mary University of London researcher Sylvian Alem attached a fake flower sprinkled with sugar water to the end of a string, placed it under a transparent sheet of glass and then put a group of bumblebees to a test. If he trained them to pull the string to get the sugar water, would they be able to learn it – and spread the skill to their colony? When Lars Chittka, a professor at the university, saw the experiment, he was surprised. "What I like about the work," Dr. Chittka said in a press release, "in addition to the experimental and intellectual challenges and insights, is the sheer absurdity of seeing bees solving a string-pulling puzzle. When lead author Sylvain Alem first showed me a bee successfully pulling on the string, I just couldn't believe what I was seeing. And even now, looking at the videos still makes me laugh."