Ways of imaging the brain, as with much of technology, changes almost daily. Dr Inaba reports on the current state of brain imaging and scanning technologies, and how they can helps us understand addictions.
Transcript (edited):
CNS: Welcome to the CNS Podcast featuring Dr. Darryl Inaba, research director for CNS Productions.
CNS: Hi I am Howard LaMere here with Dr. Darryl Inaba. Darryl, weve talked a lot about the research being done on the function of the brain and how much progress has occurred in the last 10 or 15 years because of new scanning technologies and today lets talk about some exciting innovations in that area.
DARRYL: Yes, I am extremely excited. I had the great privilege of being in Hawaii recently to present to the Coalition for Drug Free Hawaii and also to the Hawaii Pharmacists Association along with two of the top brain imaging researches from the University of Hawaii, Dr. Dan Alicata and Dr. Christine Cloak. Both work for Dr. Linda Chang, a top brain imaging researcher who works with Dr. Nora Volkow at the National Institute of Drug Abuse. These were some pretty top people and I had the pleasure of listening to their presentations and then we all spent the second half of the day together, answering questions and interacting as a panel with the audience. I was amazed to hear of the innovations in the brain imaging field and the enhanced ability to better understand how the brain operates as well as how it changes and is damaged by inherent illnesses, mental pathology, and chronic mental disorders. Just by looking at the MRIs, the functional MRIs, the CAT scans, the SPEC scans and the PET scans you can see the differences that occur as a result of addiction. I didnt realize how advanced things are today. There is a high resolution magnetic resonance image that gives a more precise view of the different structures and how they are different in addicts versus non-addicts, this also shows how the structures may change due to say methamphetamine or another drugs. There is now something called MRS magnetic resonance spectrometry which uses protons, like hydrogen, HMRS which can give a picture that is quantifiable of the brain chemistries. So, rather than having to get into the brain or making inferences from chemistry found in blood or in urine, these technologies can quantify what the dopamine level is in certain parts of your brain or your serotonin level and thats a huge innovation because thats certainly what we target in terms of treating mental illnesses as well as helping the brain recover from chemical dependency. Now that we can actually see precisely what the levels of those chemistries are we can make appropriate medical or medicine interventions to help people rebalance their brain quicker. Another interesting thing that I learned is at the University of Hawaii, theyve been developing diffusion tensor imagery. Diffusion tensor imagery uses capillary effects to track a solutions movement as it diffuses through the brain tissues. This is the first time I am aware of that researchers can actually see the networks or pathways .sort of like the fasciculus retroflexus that communicates from the frontal cortex to the medial fore brain bundle or the limbic system that helps turn off the brain once its turned on to doing things we call it the stop switch. These images show the connections between the stop and the go switch. This information can determine if there are deficits, if there has been destruction along that track, how healthy it is, how it is functioning and so on. While this level of precision is exciting the downside is the intimacy. Being able to look at a persons brain and know what theyre actual thoughts are and the details of those thoughts is extremely intimate. It also allows a treatment professional to present addiction to an addict without the denial, or proclamation that oh no, Im okay Im just having some bad luck, I really just kind of overdid it that night and didnt mean to drink so much that I got a DUI.
CNS: When you speak of looking at the functioning of networks, for instance the stop switch and the go switch what are you actually viewing? Are you viewing the transition of brain chemicals or is it a change in the physical structure?
DARRYL: Well, both the new and old tests view pretty much everything. They view actual cells and how they function as well as how healthy they are. Youre able to view how much chemistry they contain and whether or not their dopamines levels are low or serotonin levels, or glutamate GABA levels are abnormal as compared to other people. The imaging provides a window to observe the tracks and the networks and the fiber neurons that communicate from one part of the brain to another of the brain in order to deliver a message – an inhibitory message or an excitatory message, it is actual communication between different parts of the brain.
CNS: What scale are we talking about there? Are we talking about a cellular, molecular? How small are we talking?
DARRYL: Well imagine you are a mechanic working on car where you sometimes have to fix little things that you need tweezers to fix like in a carburetor and sometimes a fix will take a huge wrench…its all those levels with these different imaging technologies. When youre looking at the chemistry and the actual quantification of chemistry it is at the molecular level. Youre looking at receptor sites and assessing whether or not the density of the receptor sites are high or low, whether theyre up regulated or down regulated. Youre looking at the actual molecular tissues of the brain. When youre looking at the MRI structures and nucleus accumbens as an organ in the mid-brain, youre looking at a much larger structure. When youre looking at the fibers of connecting neurons youre looking at a track, a whole bunch of neurons range from one part of the brain to another part of the brain as it communicates. Were really becoming intimate with the brain – how it operates, how it functions, and how it differs from one person to the next.
CNS: Now this is massively different than what you would see if you simply opened up the skull and looked at the brain, right? This imaging shows process and there is a level of magnification then we could see just looking at it, correct?
DARRYL: Well, with an electronic microscope you can invade the brain and open it up and pull out the tissue to see the cell structures and the tissues on a molecular level. You can also see receptor sites, but imaging is not invasive, youre not cutting into the brain but rather watching the brain as it is working as its functioning as its processing and as its thinking about something and involved in figuring something out. Youre actually watching it process with its own chemistry, its own electricity, its own receptor sites and cells. That intimate level allows you to see it in action, which I think, is amazing.
CNS: It is truly amazing from a scientific point of view. But, I read something not too long ago about the side effects . something about the not too often discussed dangers of these various magnetic resonance imaging technologies. Was there any discussion in Hawaii about those ramifications?
DARRYL: You know, Howard, I think you have raised a significant point because unfortunately nobody talks about potential dangers. I havent seen anything about the dangers in all the presentations, in all I have read, the information focuses on the wonders were able to see. Nobody has really talked about, nor have I seen any studies on long range potential health hazards of subjecting people to these imaging techniques. Now, MRI magnetic resonance imaging used to be called NMRI short for Nuclear Magnetic Resonance Imaging and the word nuclear went away because with the advent of atomic bombs and things like that, it scared too many people. But, basically an MRI subjects the brain to really high-powered magnetic forces – actual brain protons shift and that has the potential to do something – I dont know if anybody has looked at that. The proton is usually hydrogen .in that H1 or hydrogen is used to image the brain and to observe shifts in its magnetic resonance or from its magnetic shifting from one end to the other. And Ive got to think that does something as well. The diffusion tensor imaging, which looks at different fluids going through parts of brain – water and liquids , may be an issue as well.
CNS: Just the very act of looking at something at that subatomic level, changes it. Thats mathematically proven. And its part of how we have advanced to this point where we can do these things. But everything has some costs, some tradeoffs.
DARRYL: You know thats a scary thing because quantum physics is such a chaotic unpredictable, weird thing. The things theyre finding in quantum physics when you get on the individual atoms and parts of atoms, basis were not sure what well get.
CNS: Right. Because by looking at it youve by definition changed it. And you dont know what it changes into.
DARRYL: The research on that is backward causation. The Hadron Collider looks for the Higgs boson, but they cant find it and now theyre saying its one of those quantum characteristics where you get backward causation, meaning as you say, the Heisenberg uncertainty principle when you look at something it changes something. What are the potential dangers of magnetic resonance, of brain imaging, of all the different techniques available today? I dont think its permissible to show any of these images in criminal proceedings as evidence that this is the person who did the crime, or is capable of criminal behavior. There isnt enough data for prosecutors or for the defense to rely 100% on the findings yet.
CNS: Over time it will probably reveal more of the nuances of thought, behavior and the why and how of the things we do and how we can affect those and understand them. Its fascinating stuff and well talk more about this, especially as news of it becomes available. And those of you listening, as ever, thoughts and comments and questions are certainly welcome. If you would like to make some comments, stop by our website, which is cnsproductions.com. Drop us a note there. Well reply if we can. Daryl, thank you.