John Medina on Aging Well (BS 138)


Dr. John Medina has spent his career in bio-engineering, but he also has a deep interest in how the brain works. In his latest book Brain Rules for Aging Well: 10 Principles for Staying Vital, Happy, and Sharp, he presents our knowledge brain aging in an engaging manner that can be enjoyed by readers of all backgrounds.

In this month's episode of Brain Science (BS 138) we discuss some of the most important principles for nourishing brains as we age. He describes what he calls the "dopamine lollipop," which is the surge of dopamine created by activities such as teaching and physical activities like dancing. Some of his ideas reinforce what we have discussed in previous episodes, but there are new ideas that are relevant to listeners of all ages.

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Neurobiology of Placebos with Fabrizio Benedetti (BSP 77)


Fabrizio Benedetti, MD 

Fabrizio Benedetti is one of the world's leading researchers of the neurobiology of placebos.  In a recent interview (BSP 77) he explained to me that he believes that "today we are in a very good position to describe, from a biological and from an evolutionary approach, the doctor-patient relationship, and the placebo effect, itself."

To appreciate Dr. Benedetti's work, one must first realize that his approach differs from that of the typical clinical trial.  As he observed, "To the clinical trialist, a placebo effect means any improvement which may take place after placebo administration.  To the neurobiologist, a placebo response, or placebo effect means only something active in the brain happening after placebo administration: learning, anxiety reduction, activation of reward mechanisms."

In contrast, he explains, "The real placebo response, the real placebo effect is a psychobiological phenomenon.  It is something active happening in the brain after placebo administration: like learning, like anxiety reduction, and such like." Brain Science Podcast #77 provides an introduction to this complex, but fascinating topic.

How to get this episode:


  • Benedetti F, Mayberg HS, Wager TD, Stohler CS, Jon-Kar Zubieta J (2005) Neurobiological Mechanisms of the Placebo Effect. The Journal of Neuroscience, 25,10390-10402. (Full article)
  • Benedetti F (2009) Placebo Effects: Understanding the mechanisms in health and disease. Oxford University Press.
  • Benedetti F (2011) The Patient's Brain: The neuroscience behind the doctor-patient relationship. Oxford University Press.
  • Levine JD, Gordon NC and Fields, HL (1978) The mechanisms of placebo analgesia. Lancet, 2, 654-7. (Abstract)
  • Levine JD, Gordon NC and Fields, HL (1978) “The mechanisms of placebo analgesia.” Lancet, 2, 654-7. (Abstract). See also a follow-up paper: Levine JD, Gordon NC, Bornstein JC, and H L Fields HL (1979) “Role of pain in placebo analgesia.” Proc Natl Acad Sci76(7): 3528–3531. (full text)
  • Volkow, ND, Wang JG, Ma Y, Fowler JS, Zhu W, Maynard L et al. (2003) Expectation enhances the regional brain metabolic and the reinforcing effects of stimulants in cocaine abusers. Journal of Neuroscience, 23, 11261–8. (Full text)
  • de la Fuente-Fernández R, et al. (2001) Expectation and Dopamine Release: Mechanism of the Placebo Effect in Parkinson's Disease. Science293, 1164. (Abstract)
  • Benedetti F, Colloca L, Torre E et al. (2004) Placebo-responsive Parkinson patients show decreased activity in single neurons of the subthalamic nucleus. Nature Neuroscience, 7, 587-88. (Abstract)
  • Herrnstein RJ, (1962) Placebo Effect in the Rat. Science138, 677-678.
  • Linde K, Witt CM, Streng A et al. (2007) The impact of patient expectation in four randomized control trials of acupuncture in patients with chronic pain. Pain, 128, 264-71. (Abstract)
  • See Episode Transcript for additional references.



  •  32:48 only NON-members are eligible to get a free audiobook download from our sponsor at
  • Dr. Benedetti’s first book is called Placebo Effects, not Placebo “responses”.
  • Special Thanks to Lori Wolfson for finding these mistakes and correcting them in the episode transcript.

Send me feedback at gincampbell at

Using C. elegans in Neuroscience with Guy Caldwell, PhD (BSP 59)

Episode 59 of the Brain Science Podcast is an interview with molecular biologist, Guy Caldwell, PhD, from the University of Alabama.  We talk about the role of the tiny worm C. elegans in neuroscience research.  Dr. Caldwell is collaborating with other leading researchers (including his wife, Kim Caldwell, PhD) in work that may lead to a cure for movement disorders like dystonia and Parkinson's Disease.

Kim and Guy Caldwell

Kim and Guy Caldwell

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  • New episodes of the Brain Science Podcast are always FREE.  All episodes posted after January 1, 2013, are free.  See the individual show notes for links the audio files.

Show Notes and Links:

During this interview, Dr. Caldwell emphasized the importance of collaboration.  His work involves tagging the dopamine neurons in C. elegans with green florescent protein (GFP).  His work depends on the pioneering work of many scientists (some of whom I list below).  He also collaborate with researchers who are doing similar work in yeast, mice, and human cell cultures.

Scientists mentioned in this interview:

  • Martin Chalfie (Columbia University): Caldwell's mentor won the Nobel Prize in 2008 for his work with using Green Florescent Protein (GFP) to tag specific cells inside C. elegans.  Dr. Chalfie was interviewed on Futures in Biotech: Episode 37 and Episode 38.
  • Susan Lindquist (MIT): a leading geneticist who is using to take human alph-synuclein protein and place it into yeast to study the effects of protein clumping due to misfolding. (Futures in Biotech #1)
  • Sydney Brenner (Salk Institute): a leader in C. elegans research.
  • John Sulston (University of Manchester): pioneer in C. elegans research.
  • Robert Horvitz (MIT): well-researcher in the field of worm biology.
  • Cynthia Kenyon (University of California-San Francisco): is studying aging in C. elegans.
  • John White (University of Wisconsin): worked with John Sulston to determing the complete "wiring diagram" for C. elegans (which has only 302 neurons).
  • Jeff Becker (University of Tennessee): Caldwell's mentor in graduate school.
  • Chris Rochet (Purdue University): his study of mid brain cultures of rat neurons allows Caldwell to validate his findings in mammalian neurons.
  • Richard Myers (Boston University): human geneticist who has done important work in Parkinson patient genotyping.
  • Rudolph Jaenisch (MIT): expert at reprogramming skin cells into pleuripotent stem cells. This technique shows great promise for the treatment/cure of diseases like Parkinson's.
  • Xandra Breakefield (Harvard): discovered the torsin gene in 1997.

Three recent Nobel Prizes have been awarded to researchers working on C. elegans.



  • Dr. Campbell is the guest speaker at the July 18 meeting of Skeptics in the Pub in Atlanta, Georgia.
  • Dr. Campbell was interviewed on Episode 96 of Brains Matter.
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A Clue To Why Tobacco Is So Addictive

Nancy Yanes-Hoffman sent me this review of an article just published in the Journal of Neuroscience:

That was good!" "Do it again."
This is what the brain says when people use tobacco, as well as ‘hard drugs’ such as heroin.  New research published in the February 13 issue of The Journal of Neuroscience indicates that the effects of nicotine and opiates on the brain's reward system are equally strong in a key pleasure-sensing areas of the brain – the nucleus accumbens.
"Testing rat brain tissue, we found remarkable overlap between the effects of nicotine and opiates on dopamine signaling within the brain’s reward centers," says Daniel McGehee, Associate Professor in Anesthesia & Critical Care at the University of Chicago Medical Center.
McGehee and colleagues are exploring the control of dopamine, a key neurotransmitter in reward and addiction.  Dopamine is released in areas such as the nucleus accumbens by naturally rewarding experiences such as food, sex, some drugs, and the neutral stimuli or ‘cues’ that become associated with them.
Nicotine and opiates are very different drugs, but the endpoint, with respect to the control of dopamine signaling, is almost identical.  “There is a specific part of the nucleus accumbens where opiates have been shown to affect behavior, and when we tested nicotine in that area, the effects on dopamine are almost identical,” says McGehee.
This research is important to scientists because it demonstrates overlap in the way the two drugs work, complementing previous studies that showed overlapping effects on physiology of the ventral tegmenal area, another key part of the brain’s reward circuitry.  The hope is that this study will help identify new methods for treating addiction – and not just for one drug type.
"It also demonstrates the seriousness of tobacco addiction, equating its grip on the individual to that of heroin.  It reinforces the fact that these addictions are very physiological in nature and that breaking away from the habit is certainly more than just mind over matter," says McGehee.
This work is supported by grants from the National Institutes of Health, T32GM07839 and F31DA023340 to JPB, DA015918 and DA019695 to DSM.
    • Jonathan P. Britt and Daniel S. McGehee, "Presynaptic Opioid and Nicotinic Receptor Modulation of Dopamine Overflow in the Nucleus Accumbens,"The Journal of Neuroscience, February 13, 2008 • 28(7):1672–1681

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      "Why Choose this Book?" with Read Montague (BSP 15)


      Show Notes

      Episode #15 of the Brain Science Podcast is an interview with Dr. Read Montague of the Baylor School of Medicine.  We discuss his recent book, Why Choose this Book? How we Make Decisions (2006).

      How to get this episode:

      • Premium Subscribers now have unlimited access to all old episodes and transcripts.
      • Buy mp3 for $1
      • Buy Transcript for $1.
      • New episodes of the Brain Science Podcast are always FREE.  All episodes posted after January 1, 2013, are free.  See the individual show notes for links the audio files.

      Here are some of the questions we discussed:

      • What is computational neuroscience?
      • What is the computational theory of the mind (CTOM)?
      • How isthe objection that the CTOM doesn't account for meaning answered ?
      • What about choice and responsibility?
      • Is there room for free will in this model?

      How Neurons Communicate: A Detailed Introduction (BSP 8)


      When I started preparing for this week's episode I realized that before I could discuss neurotransmitters (brain chemicals) I would need to discuss some basic information about how neurons work. Thus this episode is rather long and technical, but hopefully understandable to those who are new to the field. I am including more detailed show notes than I usually do, along with the approximate times for the main sections, in case there is a particular topic you want to go back and review.

      How to get this episode:

      • Premium Subscribers now have unlimited access to all old episodes and transcripts.
      • Buy BSP 1-10 (zip file of mp3 files)
      • Transcripts: BSP 1-14
      • New episodes of the Brain Science Podcast are always FREE.  All episodes posted after January 1, 2013, are free.  See the individual show notes for links the audio files.

      The main source for this episode was the textbook, From Neuron to Brain: A Cellular and Molecular Approach to the Function of the Nervous System, Fourth Edition (2001)

      Topic Outline:

      2:39-11:33 Neuronal signaling-the basics of electrical and chemical signaling types of signaling-electrical and chemical introducing the synapse the importance of membrane proteins

      11:55 - 13:03   A bried discussion of how the brain differs from a  digital computer

      13:3 3-13:50   Definition of neurotransmitters-

      13:56 -22:10   How neurotransmitters interact with receptors in the synapse

      -direct and indirect  chemical synapses-why they are important

      -neuromuscular junction-an example of a direct chemical synapse

      -the importance of synaptic delay

      -the role of second messengers in indirect chemical synapses

      -release and recycling of neurotransmitters

      22:25 -29:42 Types of Neurotransmitters and how they work-with examples

      -how neuropeptides differ from low molecular weight neurotransmitters

      -a little about how drugs work

      29:58 - 41:54  How Neurotransmitters function in the Central Nervous System-with examples

      -Glutamate is the key excitatory neurotransmitter in the brain

      -an aside about Nutrasweet™ (30:33)

      -glycine and GABA are inhibitatory

      -acetycholine (33:32-34:34)

      -discussion of Molecules of Emotion by Candace Pert (35:30-36:55)



      -dopamine and Parkinson's disease

      42:07 - 43:36  Closing Summary