Neuroscience


Want more working memory? Then you need to expand your brain. Credit: Flickr/Elena Gatti, CC BY

By Joel Pearson

Before we had mobile phones, people had to use their own memory to store long phone numbers (or write them down). But getting those numbers into long-term memory could be a real pain.

When we learn, we associate a sensory experience with other stimuli or with a certain type of behavior.

The neurons in the cerebral cortex that transmit the information modify the synaptic connections that they have with the other neurons and according to a generally accepted model of synaptic plasticity, a neuron that communicates with others of the same kind emits an electrical impulse as well as activating its synapses transiently. This electrical pulse, combined with the signal received from other neurons, acts to stimulate the synapses.


Until the last few decades, the frontal lobes of the brain were shrouded in mystery and erroneously thought of as nonessential for normal function—hence the frequent use of lobotomies in the early 20th century to treat psychiatric disorders. A review in Neuron highlights studies of patients with brain damage that reveal how distinct areas of the frontal lobes are critical for a person's ability to learn, multitask, control their emotions, socialize, and make real-life decisions. 


Learning a new skill is easier when it is related to an ability we already have. For example, a trained pianist can learn a new melody easier than learning how to hit a tennis serve.

Scientists from the Center for the Neural Basis of Cognition (CNBC) have discovered a fundamental constraint in the brain that may explain why this happens. Writing in Nature, they say that there are limitations on how adaptable the brain is during learning and that these restrictions are a key determinant for whether a new skill will be easy or difficult to learn. Understanding the ways in which the brain's activity can be "flexed" during learning could eventually be used to develop better treatments for stroke and other brain injuries.


Functional magnetic resonance imaging (fMRI) has led University of Illinois at Chicago scholars to conclude that young adults who previously experienced the mental illness have hyper-connected emotional and cognitive networks in the brain.

The college students were ages 18 to 23 while they were in a resting state. 30 un-medicated young adults who claimed to have experienced depression and 23 healthy controls were used in the study, which has published in PLOS ONE.

"We wanted to see if the individuals who have had depression during their adolescence were different from their healthy peers," said Rachel Jacobs, assistant professor in psychiatry and lead author of the study.



Image credit: vastateparksstaff via flickr | http://bit.ly/1niJe8g. Rights information: http://bit.ly/cGotEb

A parasitic fungus that reproduces by manipulating the behavior of ants emits a cocktail of behavior-controlling chemicals when encountering the brain of its natural target host, but not when infecting other ant species, a new study shows.

The findings, which suggest that the fungus "knows" its preferred host, provide new insights into the molecular mechanisms underlying this phenomenon, according to researchers.

"Fungi are well known for their ability to secrete chemicals that affect their environment," noted lead author Charissa de Bekker, a Marie Curie Fellow in Penn State's College of Agricultural Sciences, and Ludwig Maximilian of the University of Munich. "So we wanted to know what chemicals are employed to control so precisely the behavior of ants."


Researchers have found that a loss of cells in the retina is one of the earliest signs of frontotemporal dementia (FTD) in people with a genetic risk for the disorder—even before any changes appear in their behavior.


Using a combination of genetic and optical techniques, researchers at the Champalimaud Neuroscience Programme have established the effect of serotonin on sensitivity to pain.

"Serotonin is a small molecule known to be implicated in a wide range of brain functions, from the control of sleep and appetite, to the regulation of complex emotional behaviours, This neurotransmitter is also popularly thought to contribute to feelings of well being and happiness, as some anti-depression medications work through increasing serotonin in the brain," says Zachary Mainen, CNP director and principal investigator of the Systems Neuroscience Lab.


Silent strokes are a loss of blood flow to parts of the brain. Such strokes do not cause immediate symptoms and typically go undiagnosed, but they cause damage. In kids, they can even lower IQ.