Episode #86

News Items

    ADHD

    • HelloRecently the Infidel Guy, (www.infidelguy.com/) had an interview with Dr. Fred A. Baughman (www.adhdfraud.com/) about what Dr. Baughman calls the ‘Fraud of ADHD’. He claims that there is no ‘disease’ behind ADHD and the medications should not be prescribed for what are basically normal behaviours.His basic argument is that ADHD has no physiological manifestation, that is, you can’t determine if someone has ADHD by only looking at their physiology, and thus it is not a ‘disease’ (or even a ‘disorder’, which he claims is an equivalent term). Dr. Baughman definitely sounds like he has a problem with psychiatry, but if he his right, that might be justified.You can listen to the episode here:infidelguy.libsyn.com/index.php?post_id=188241#I’ve always been a little uncomfortable with the number of cases ADHD, given that the symptoms seem to be little more that disobedient behaviour, however that does not mean there is not a real disorder in some cases.I was hoping you might be interested in discussing this on the show.ThanksDarin OhashiNote: Written debate with Dr. Novella on ADHDwww.theness.com/articles.asp?id=35www.theness.com/articles.asp?id=36
    • Hello, recently I read an article that states that a new theory has formed about how nerves communicate to each other. This theory abandons the idea that nerves use electrical impulses to send messaged between one another, and states that nerves use sound waves to send messages. My question is for Steven Novella(nice name by the way), what are your thoughts on the likely hood of this theory being shown true, and what would the implications be for medicine.Also, the article states that nerves do not generate heat when the supposedly ‘fire’ electrical impulses, is that statement accurate? How would this be explained against thermodynamics?Finally, how would the sound theory explain electrical currents effecting muscle contractions and other nerve functions.The article is located here: www.cbc.ca/technology/story/2007/03/09/science-nervessound-20070309.htmlSteven RandolphSt Petersburg, FloridaE-mail from the lead author in response to my questions:Dear Steve NovellaTypically we communicate with colleagues through scientific articles. The press release of the press department of our University developed a life on its own that I find partially disturbing.We receive mail from a lot of very strange people – but also some genuine interest.There is a number of serious international daily journals from Danmark, Brazil and the USA that want to cover the story or already did so.The press release came out in the States only on Sunday. So it is a bit early to comment on the response. We had letters from some serious colleagues that want explanations and pdfs of the articles. Some of them actually read the original articles. That is the kind of response that I favor.Our model makes the easy-to-understand statement that currents through resistors should produce heat. However, a number of very respected colleagues over the past 50 years have noted that there is no net heat released.The first person to point this out was Adrian V. Hill in 1958. He was advisor of Hodgkin in Cambridge and he won the Nobel prize for his heat measurements in 1922. He pointed out that during the action potential a phase of heat release is followed by heat reabsorption. Within the accuracy of the measurement this heat re-uptake is complete. This is typical for mechanical waves or pulses, but not for dissipative phenomena as proposed by Hodgkin and Huxley. Hodgkin himself took this point very seriously and dedicated a whole paragraph to this finding in his textbook on nerves.Our proposal that nerve pulses are density solitons does not imply, however, that the pulse has no electrical component. Membranes are charged capacitors and we see the pulse as a piezo-electric pulse. Thus, like in Hodgkin-Huxley our pulse consists of a nerve segment of charged capacitor that travels along the axon. In contrast to Hodgkin- Huxley this is based on reversible physics that does not consume energy. The measured currents are capacitive currents instead.When it comes to EEGs I therefore do not expect any difference.Further, like Hodgkin-Huxley our model is meant to explain the propagation of pulses in the nerve axon but not the processes within the synapse. Therefore, our model does not make any statements on what happens in the synapse. We do not dispute in our papers the pharmacological evidence for synaptic processes.Our studies are based on very sound physics published in respected journals. They look at biological systems from a very different perspective – one that is rooted in the laws of thermodynamics. Interestingly, this approach may yield an explanation for the action of general anesthetics that is extremely simple. This principle is freezing-point depression. Important also: in contrast to existing models it can be proven wrong – this I find an important characteristic of a sober and sound theory. It should make testable predictions!When it comes to the response from the science community:A large part of the physics, biophysics and physical chemistry community in my field strongly greets these developments. They find the whole idea attractive and convincing. In contrast to the more molecular-biology based models they find it intuitive and easy to understand. Typically I can easily convince my (interdisciplinary) audiences about the problems with the text-book models and our anesthesia story within 45 minutes. There is a huge interest and desire in the more physical disciplines to understand the underlying biology problems.Neurobiologists and biologists are typically interested and open to such a proposal. While they typically don’t care what the physical origin of these pulses really is, they find it very attractive that one can explain the phenomenon of general anesthesia very easily with high predictive power.The community that does not like our approach are ion-channel scientists. Our models do not make any explicit mention of ion channels and don’t need them. For obvious reasons this community finds that disturbing. I do not dispute any of the findings in this field. I come from the Max-Planck Institute in Gottingen/Germany where patch-clamp was developed and was a group leader there. I question, however, a number of the interpretations of these findings. I have never ever met a serious scientist who disputed that fact that there is reversible heat in nerve and that this implies reversible physics. Even patch-clamp experts find this convincing (at least those with a basic understanding of thermodynamics).Like all science our models could of course be wrong or incomplete. Scientific papers always represent the present level of discussion. Our studies are meant to trigger such a discussion. But to disprove the basic idea would require serious thinking and investigation because the underlying physical argument is quite strong.I hope that helps.The original quotes are:T. Heimburg and A. D. Jackson. 2007. On the action potential as a propagating density pulse and the role of anesthetics. Biophys. Rev. Lett. 2: 57-78T. Heimburg and A. D. Jackson. 2007. The thermodynamics of general anesthesia. Biophys. J. (May issue)T. Heimburg and A. D. Jackson. 2005. On soliton propagation in biomembranes and nerves. Proc. Natl. Acad. Sci. USA. 102: 9790-9795.Best regards, T.Heimburg

    Science or Fiction

    • Item #1 Science

      Researchers have found they can decrease the hearing damage caused by very loud noises by pre-treating with an anti-epilepsy drug.

    • Item #2 Fiction

      Scientists have discovered a new species of mammal 125 million years old which they believe to be the long sought after missing link in bat evolution.

    • Item #3 Science

      Scientists have proposed a new process for turning biomass into liquid fuel and they claim that with this method agricultural and forest waste could be turned into enough fuel to meet the US’s entire transportation needs.

    Skeptical Quote of the Week.