Same brain chemistry involved in sex, drugs and rock & roll

According to a study by McGill University researchers published in the Nature journal Scientific Reports, the same brain-chemical system involved in the feelings of pleasure from sex, recreational drugs, food were also responsible in experiencing musical pleasure. McGill scientists revealed brain’s own opioids are involved in musical pleasure

“This is the first demonstration that the brain’s own opioids are directly involved in musical pleasure,” says cognitive psychologist Daniel Levitin, senior author of the paper.

Levitin’s lab and others had previously used neuroimaging to map areas of the brain which are active during musical pleasure, however, scientists were only able to guess the involvement of the opioid system.

Daniel levitin’s lab (Photo courtesy of McGill University).

In this new study, Levitin’s team at McGill temporarily and selectively blocked opioids in the brain using naltrexone, a popular drug used in treating addiction disorders.

After this procedure participant’s response to music was measured,  the results showed that even the participant’s favourite songs no longer resulted in feelings of pleasure.

“The findings, themselves, were what we hypothesized,” Levitin says. “But the anecdotes — the impressions our participants shared with us after the experiment — were fascinating. One said: ‘I know this is my favourite song but it doesn’t feel like it usually does.’ Another: ‘It sounds pretty, but it’s not doing anything for me.’”

Many things people enjoy can lead to addictive behaviour that can harm lives and relationships such as  alcohol, sex and a friendly poker game to name a few. As a result, understanding the neurochemical roots of pleasure has been a key factor of neuroscience research for decades. However, scientists have only recently been able to do such research in humans.

Still, this study proved to be “the most involved, difficult and Sisyphean task our lab has undertaken in 20 years of research,” Levitin says. “Anytime you give prescription drugs to college students who don’t need them for health reasons, you have to be very careful to ensure against any possible ill effects.” To ensure there are no potential side effects , all 17 participants were required to take a blood test within a year following the experiment, in order to make sure they didn’t have any conditions that would be made worse by the drug.

Music’s ability to deeply effects emotions and its universality suggest an evolutionary origin, and the new findings “add to the growing body of evidence for the evolutionary biological substrates of music,” the researchers wrote.

Incretin-based drugs for diabetes and their adverse effect

A popular group of drugs used to treat type 2 diabetes was shown to have no association with acute pancreatitis but an increased risk of bile duct and gallbladder disease. This was revealed  based on the  first population-based study investigating the possibility of an association with incretin-based drugs. These drugs are proven to be excessively popular for their effectiveness without causing hypoglycaemia, a problem with other classes of diabetes medications. Furthermore, they are shown to have beneficial effects on body weight.

“Early signal detection studies suggested that an association might exist. The suspicion was credible because these drugs act directly on the pancreas and there was a concern that they could be responsible for inflammation,” said Dr. Laurent Azoulay, Senior Investigator at the Lady Davis Institute at the Jewish General Hospital and Associate Professor in the Department of Epidemiology, at McGill University. “However, ours was the largest study ever to address the question – involving a cohort of more than 1.5 million patients – and there is no evidence to support that either type of incretin-based drug causes acute pancreatitis.”


Two studies led by Dr. Azoulay at Mcgill University, demonstrated that despite an increased risk of bile duct and gallbladder disease, incretin-based drugs are not associated with increasing the risk of acute pancreatitis. (Photo courtesy of:


Although  they have been prescribed to millions of patients, the safety of the drug remains controversial. Two studies led by Dr. Azoulay, demonstrated that despite an increased risk of bile duct and gallbladder disease, these drugs are not associated with increasing the risk of acute pancreatitis. Both studies are published in the JAMA Internal Medicine.

“Notwithstanding the latter finding, the totality of the evidence accumulated to date suggests that incretin-based drugs are effective and generally safe,” Dr. Azoulay concludes. “Nonetheless, it’s important that clinicians and patients alike be well informed about possible adverse effects. As a result of the gallbladder finding, it would be prudent for doctors to warn their patients to seek treatment if they experience symptoms, such as pain in their right side.” The most prevalent adverse effect is gallstones which are treatable but can cause extreme pain. In very severe cases the surgical removal of the gallbladder may be required.

The study concluded that nearly 3 more individuals per 1000 will exhibit symptoms as compared with those not taking this medication.

“Clinical trials are the gold standard to assess whether medications are effective, but because of their relative small sample sizes and short durations of follow-up, they are not designed to assess the risk of uncommon but clinically important adverse events,” said Dr. Azoulay, “this is where well designed studies conducted in the real-world setting can provide critical information on the safety of medications.”

New technique could rewire and grow new neurons

A new technique will potentially create new neurons and allow them to reconnect in people with central nervous system damage.

A research team led by McGill University and the Montreal Neurological Institute has created new functional connections between neurons for the first time.

These artificial neutrons grow 60 times faster, but are identical to naturally growing neurons in the human body.

(Courtesy of: McGill University)

“It’s very exciting, because the central nervous system doesn’t regenerate”, said Montserrat Lopez in a statement, a McGill post-doctoral fellow who spent four years developing, fine-tuning and testing the new technique. “What we’ve discovered should make it possible to develop new types of surgery and therapies for those with central nervous system damage or disease.”

To make healthy neuronal connections that transmit electrical signals in the same way that naturally grown neurons do, precise manipulation and specialized instruments are needed. This amount of precision is due to the minute size of the neurons, which are 1/100th of a single hair strand. An atomic force microscope is used to stretch the transmitter part of a neuron and reconnect with the part of the neuron that acts as a receiver.

Margaret Magnesian, a neuroscientist at the Montreal Neurological Institute and an author on the paper “Rapid Mechanically Controlled Rewiring of Neuronal Circuits,” says ”this technique can potentially create neurons that are several [millimetres] long, but clearly more studies will need to be done to understand whether and how these micro-manipulated connections differ from natural ones.”