All posts by Callum Tyndall

Scientists genetically engineer cocaine addiction-proof mice

Scientists from the University of British Columbia have genetically engineered several mice that are resistant to cocaine addiction.

By increasing the levels of a protein called cadherin in the mice, the scientists essentially prevented the pleasurable memory of cocaine from forming in the mice and leading to addiction.

The cadherin protein helps bind cells together and, in the brain, helps to strengthen synapses between neurons.

This strengthening of synapses is integral to learning, including forming the memory of the pleasure induced by stimulants, and thus led to the belief that the mice with increased cadherin would in fact be more susceptible to addiction.

Shernaz Bamji, a professor in the Department of Cellular and Physiological Sciences, and her colleagues injected cocaine into mice over several days and immediately placed them in a distinctly decorated compartment in a three-room cage. The notion was that the mice would associate the cocaine rush with that compartment and gravitate towards it.

After the cocaine treatment days, the mice were put in the cage and allowed to go where they wished. It was found, to the researchers’ surprise, that while the normal mice would always head to the cocaine-associated compartment, the cadherin boosted mice would spend only half as much time there.

The results indicated that the engineered mice hadn’t formed the strong memories of the drug that would be expected and, following brain tissue analysis, it was found that extra cadherin prevents a type of neurochemical receptor from migrating from the cell’s interior to the synaptic membrane. Without said receptor, neurons find it harder to receive signals from adjoining neurons and the synaptic memory of cocaine’s high thus does not “stick”.

“Through genetic engineering, we hard-wired in place the synapses in the reward circuits of these mice,” said graduate student Andrea Globa, a co-lead author with former graduate student Fergil Mills. “By preventing the synapses from strengthening, we prevented the mutant mice from ‘learning’ the memory of cocaine, and thus prevented them from becoming addicted.”

Video courtesy of University of British Columbia

The researchers’ findings go a long way towards explaining the findings of previous studies that showed people with substance abuse problems have more genetic mutations associated with cadherin and cell adhesion. Furthermore, the evidence that addiction is as much genetically predilected as a result of poor decision making could allow for prediction of vulnerability to drug abuse.

Unfortunately, there are still pitfalls ahead. While increasing cadherin in humans could help with a resistance to addiction, it could pose other risks. In many cases, it’s important to strengthen synapses – even in the reward circuit of the brain.

“For normal learning, we need to be able to both weaken and strengthen synapses,” Dr. Bamji says. “That plasticity allows for the pruning of some neural pathways and the formation of others, enabling the brain to adapt and to learn. Ideally, we would need to find a molecule that blocks formation of a memory of a drug-induced high, while not interfering with the ability to remember important things.”

US House Science Committee promotes fake news on climate change

The US House Committee on Science, Space & Technology has apparently decided that they too need to get into the business of alternative facts, by hosting a Mail on Sunday article that falsely claims a major climate change study had exaggerated global warming. The article, which is currently the top entry under news on the committee’s website, is categorically nonsensical and has been thoroughly deconstructed by Snopes.

The Mail on Sunday, an offshoot of the equally disreputable Daily Mail, alleges that, in order to influence the Paris Climate Agreement, America’s National Oceanic and Atmospheric Administration (NOAA) used misleading and unverified data to exaggerate global warming in a June 2015 paper published in the journal Science entitled Possible artifacts of data biases in the recent global surface warming hiatus. The allegations stem from supposed whistleblower, Dr John Bates, a retired NOAA scientist.

Supposedly, according to the article’s author David Rose, NOAA not only broke general organisation protocols by failing to archive their data and rushing through the internal review process but used “flawed” data from a doubtful source. The article of course ignores that the study actually fully took into account the data differences inherent in the research.

A screenshot of the Science, Space & Technology Committee’s website, showing the provably false article linked on the bottom left

The range of issues with the allegations is astonishing, but let’s start with one of the bigger ones: the fact that the very “whistleblower” himself stated in an interview with E&E News that he does not believe that the data of the study was manipulated in any way. The issue he takes was instead that he felt the timing of the paper was rushed out.

Well, a rushed paper certainly seems problematic, and sure it could have played a part in the Paris Agreement. Except for the fact that said Agreement had been in discussion for four freaking years when the study was published.

In addition, the original article’s author, and director of the NOAA’s National Centers for Environmental Information, Thomas R Karl states that not only was Bates’ only role to organise the internal review process but that there was never any kind of critique of the data used.

“There were] no discussions, nor emails to me. Dr Bates was asked to coordinate the internal review of the paper (I am not sure who made the request) since this was normally handled by Tom Peterson, but he was one of the authors,” he said. The responsibility of the coordinator for the internal review is to identify an individual within the [National Centers for Environmental Information] who could review the paper and pass those comments back to the authors for their response. In our case, there were no comments by the reviewer.”

It should moreover be noted that despite the allegations of obscured and misappropriated data, the entire methodology was spelled out in the paper and there was a further study this January, absent from the Mail’s article, that showed the data record from Karl et al’s study was more accurate than any other model.

Oh, and just in case you still though the timing might be problematic? The actual US State Department came out and said that the study had little to no bearing on the Paris Agreement. Aside from the fact that the negotiations had been underway for years before the study was even published, according to a statement to E&E news, the negotiating team were barely aware of the study.

“I never heard it discussed once, let alone this one NOAA report, discussed in Paris, the run-up to Paris or anything after Paris, so this is really just an incredibly bizarre claim,” Andrew Light, a senior member of the State Department’s climate talks 2015 negotiating team, said.

Let’s just go ahead and say that, in the best of lights, the Trump administration is a little behind the times in regards to climate change (to give just one example, a man who sued the EPA 14 times now put in charge of the agency). But to see an actual House Committee selectively promote an article when it has been so thoroughly refuted bodes very poorly for the future of policy related to climate change.

It does, however, seem in line with other comments made by the committee’s chairman, Lamar Smith. “The United States’ contribution to the Paris Climate Agreement, which includes the Clean Power Plan, could cost up to $176bn annually, and would have no significant impacts on climate change,” he said in a statement on the agreement in November.

With an administration that seems determined to blindly disbelieve hard science in favour of short-term greed, future US action on climate change is deeply dubious.