Do you remember the time when... How episodes shape our memories by Jai Yu!

Imagine sitting with your friends chatting about previous trips. You might mention the time when you went to a beautiful waterfall. You mention some details of the event, like the sun, weather and scenery. You can remember the activities from that day. But would you remember the exact duration you were at the waterfall, apart from a crude number? Or what you did the day earlier or the day later. Probably not so clearly. The event became fresh in your memory, but many details were lost to time. How does the brain retain this experience.

Jai and colleagues investigated the phenomena of coding experiences in the brain to understand how the mind recollects past experiences. They used an interesting model where a rat's behavior is monitored while it searches for a reward and then consumes it. The rat's activity gets divided into mobility (searching for reward) and immobility (consumption of reward). The rat's brain uses the changes in activity as switches to break time into discrete chunks. Each chunk becomes an episode and might be processed and saved differently. This way the brain could define interesting parts of experience and save them as separate memories, such as memories of experience on paths to reach rewards versus memories of being at those reward locations. To know more on how this happens, please listen to Jai.



To know more, please refer to:
Distinct hippocampal-cortical memory representations for experiences associated with movement versus immobility
eLife, Aug., 2017

The sugar deception! Interview with Maria Veldhuizen to know if our brain can tricked into uncoupling sweetness from calorie content.

We all know of diet drinks and sugar-free desserts. Such foods have ingredients that are sweet, but low in calorie. The temptation to savor and relish sweet foods without paying the price of high calorie intake is pretty tempting, isn't it? But does taking food items with a mismatch in sweetness and calorie content actually work on our brains? Can our brain detect the disparity?

Maria and colleagues wanted to understand the affect of discrepancy between the sweetness of the food and its calorie content on the brain's response and metabolism. By providing people drinks that were of the same nutritional value, but varying in calorie, they found that the body responded the best when the two things, sweetness and calories, matched. This suggested that calories are not the only factor that trigger metabolic and mental responses. It could be that the brain's reward circuits better register foods that match in their sweetness and nutritional content. This is of great importance because we live in a world where increasing amounts of food contain such mismatches. To know more, please listen to Maria.


To know more, please refer to:
Integration of Sweet Taste and Metabolism Determines Carbohydrate Reward
Maria et al., Current Biology, 2017

Is believing seeing? Interview with Benedikt Ehinger on how humans percieve unreliable information!

We use the information from our senses to make sense of the world. But sometimes, the information can be unreliable. What does our mind do in face of corrupted information?

Benedikt and colleagues wanted to understand how our mind makes sense of the world when faced with unreliable information. They used the model of blind spot, a part of our visual field that does not detect light. Our mind fills-in the blind spot such that we are not aware of its presence. The experiment was set up to find out if we are aware of 'information filling-in', which makes the blind spot a source of unreliable information. Unexpectedly, not only are we not aware of the unreliability of the information, we in-fact prefer the filled-in information from the blind spot over reality. In the words of André Breton, “The imaginary is what tends to become real.” To know more, please listen to Benedikt.


To know more, please refer to:
Humans treat unreliable filled-in percepts as more real than veridical ones.
Benedikt Ehinger, et al., eLife, May, 2017

Don't judge a book by its cover. Different neural circuitry underlying similar behavior by Akira Sakurai!

It is assumed that similar behaviors are generated by similar neuronal mechanisms. If nature has found one way of doing things, it will reuse it again and again for the same purpose. Akira and colleagues wanted to investigate this phenomena in the swimming behavior of two closely related molluscs. The swimming behavior of the two species is generated by very similar neurons, yet when they looked closely, the connections between neurons differed drastically. This suggested that the swimming behavior used the same same blueprint, but different architecture. To know more, please listen to Akira.  


For more information, please refer to:
Artificial Synaptic Rewiring Demonstrates that Distinct Neural Circuit Configurations Underlie Homologous Behaviors
Akira Sakurai and Paul S. Katz, Current Biology, June 2017

Blood from lungs! Interview with Emma Lefrançais on platelet production in lungs!

Blood nourishes every part of our body. It is generated every day to carry oxygen and food towards, and garbage away from every cell. Our lungs breathe in the oxygen that goes to the blood and remove carbon dioxide from it. Do lungs passively interact with circulating blood, or can they even generate new blood cells and spread them through the body?

Emma and colleagues wanted to test lungs as an active area of blood production. For this, they live imaged the blood cells within the lungs of mice. This amazing feat showed them platelets being born inside of the lung. And this pool of platelets were not a minority, but a significant part of blood count. Not only did they find platelet birth, but they also found blood stem cells living in the lung. These cells could, under certain conditions, help recover many types of blood cells! To know more about this exciting and profound discovery, please listen to Emma.


For more information, please refer to:
The lung is a site of platelet biogenesis and a reservoir for haematopoietic progenitors
Lefrançais et al., Nature, 2017

How deep breaths help with relaxation -- Interview by Kevin Yackle!

The one advice for relaxation is to take deep breaths. Yoga practitioners and doctors alike give this age-old advice. But how does our body connect breathing with calmness? Or is this a placebo effect??

Kevin and colleagues wanted to understand the biological connection between breathing and relaxation. For this, they targeted a specific region in the brain that is involved in controlling breathing. They killed a small region within this special area. Surprisingly, and fortunately, the animal's breathing did not stop. But it was slower, and was connected to the animal being calm under normal conditions! This showed a link between deep, slow breaths and a relaxed state of mind. To know more, please listen to Kevin.



For more information, please refer:
Breathing control center neurons that promote arousal in mice
Yackle et al., Science, 2017

Honeybees to Drones! Interview with Mark Roper on visual detectors for navigation!!

You must have all experienced a honeybee buzz around you, avoiding all your attempts at hitting it. These tiny animals are amazing at navigation. They move around like superman finding little flowers with ease. What makes them so good at navigation?

Mark and colleagues wanted to understand the amazing navigation capabilities of honeybees and generate a model of it. One would imagine that the system would be highly complex, with tons of interactions. But they show that the system can not only be modeled on a very few components, but it has a simplistic architecture. This generates a small and efficient system, which can be useful for helping us generate better navigation algorithm for daily life. As an instance, drones require large amounts of battery power for flying, which restricts the distance they can travel. But using honeybees based navigation system can allow them to be lighter and less power consuming, allowing them to fly much longer distances. Please listen to Mark to know more.



To know more, please refer to:
Insect Bio-inspired Neural Network Provides New Evidence on How Simple Feature Detectors Can Enable Complex Visual Generalization and Stimulus Location Invariance in the Miniature Brain of Honeybees
Roper et al., PLoS Computational Biology, 2017