Weekly Neuroscience Update

Neuroscientists have announced a longitudinal research collaboration to investigate the emotional, social and cognitive effects of musical training on childhood brain development. The five-year research project, Effects of Early Childhood Musical Training on Brain and Cognitive Development, will offer USC researchers an important opportunity to provide new insights and add rigorous data to an emerging discussion about the role of early music engagement in learning and brain function.

UCLA researchers have for the first time measured the activity of a brain region known to be involved in learning, memory and Alzheimer’s disease during sleep. They discovered that this part of the brain behaves as if it’s remembering something, even under anesthesia, a finding that counters conventional theories about memory consolidation during sleep.

New research reveals that stroke may be affecting people at a younger age. The study is published in the October 10, 2012, online issue of Neurology, the medical journal of the American Academy of Neurology.

Scientists studying a rare genetic disorder have identified a molecular pathway that may play a role in schizophrenia, according to new research in the October 10 issue of The Journal of Neuroscience. The findings may one day guide researchers to new treatment options for people with schizophrenia — a devastating disease that affects approximately 1 percent of the world’s population.

Researchers from the University of Exeter Medical School have for the first time identified the mechanism that protects us from developing uncontrollable fear.

Small amounts of the drug ketamine can immediately relieve the symptoms of chronic depression, as well as those of treatment-resistant patients within a few hours, say Yale scientists.

Scientists find that competition between two brain regions influences the ability to make healthy choices.

A compassion-based meditation program can significantly improve a person’s ability to read the facial expressions of others, finds a study published by Social Cognitive and Affective Neuroscience. This boost in empathic accuracy was detected through both behavioral testing of the study participants and through functional magnetic resonance imaging (fMRI) scans of their brain activity.

A study in PLOS ONE shows that whether or not you like the person you’re watching can actually have an effect on brain activity related to motor actions and lead to “differential processing” – for example, thinking the person you dislike is moving more slowly than they actually are.

Your Brain On Cannabis: Part Two

This a follow on post from last month’s Your Brain On Cannabis, which has become one of the most widely read posts on Inside the Brain.

The effects of marijuana on your brain

The drug acts in areas of the brain involved in memory and emotion by interacting with two receptors – the so-called CB1 and CB2 cannabinoid receptors – to cause a profound effect on recent memory. Long term memories are not affected. One brain region called the hippocampus has receptors for endogenous “marijuana” (anandamide). Hippocampal damage is associated with failure to make new memories and if the CB1 and CB2 receptors are stimulated activity decreases in this brain region.  Interestingly, with repeated use, tolerance to loss of memory develops but this is often associated with a further increase in drug intake.

Learning and marijuana don’t mix

Marijuana also changes the way sensory information is processed in the brain and is associated with poor performance in school and increased delinquency. There is impairment in the ability to learn. Listening and repetition learning is also compromised. Heavy marijuana use is associated with deficits in mathematical skill and verbal expression. Taken together these effects can lead to catastrophic social and psychological consequences particularly for the young abuser – not to mention the lost employee productivity, public health care costs, accidents and crashes and loss of income – Americans spent $10.6 billion on marijuana purchases in 1999.

Marijuana is addictive

Marijuana addicts experience withdrawal and an animal model for dependence has been developed by scientists to understand how this happens. Withdrawal has been described after 21 days of heavy use and starts 10 hours after stopping and includes insomnia, nausea, anorexia, agitation, restlessness, irritability, depression and shaking (tremor). The symptoms peak within 48 hours and gradually wear off by the fifth day of abstinence.

The war on marijuana starts with spreading the word

During the 1970s in the US it was decided that a liberal approach be adopted to marijuana use and 11 states decriminalized marijuana, 30,000 head shops were allowed to spring up and “responsible-use” messages were promoted. The drinking age was lowered to 18 years and the sale of cigarettes and alcohol to teens was tolerated. By 1979 35% of adolescents, 65%of high school seniors and 70%of young adults had tried an illicit drug. These facts and the increase in drug-related crime prompted universal outrage and the laws were tightened up. As a result – from 1979 to 1992 marijuana use has dropped by 2/3 among adolescents, and young adults and daily marijuana use has dropped by 500%. However, it has taken over 20 years to undo the damage in the US.

In tackling the marijuana problem head-on  – the following common myths need to be debunked (i) marijuana is harmless, (ii) marijuana is not addictive (iii) youth experimentation is inevitable and (iv) the criminalization of marijuana use is what leads to crime, not the drug itself.

In the final part of this series on the effects of cannabis on your brain, we will take a look at the possible medicinal uses of marijuana.

Weekly Neuroscience News

Scientists identify link between size of brain region and conformity.

Although there are several drugs and experimental conditions that can block cognitive function and impair learning and memory, researchers have recently shown that some drugs can actually improve cognitive function. The new multi-national study, published in the 21 February issue of the open-access journal PLoS Biology, reveals that these findings may implicate scientists’ understanding of cognitive disorders like Alzheimer’s disease.

New connections between brain cells emerge in clusters in the brain according to a study published in Nature on February 19 (advance online publication). Led by researchers at the University of California, Santa Cruz, the study reveals details of how brain circuits are rewired during the formation of new motor memories.

A new study shows that depression is linked to hyperconnectivity of brain regions.

A study in the February issue of Neurosurgery reveals that deep brain stimulation (DBS), commonly used to treat individuals with movement disorders or chronic pain, also affects respiratory function.