Description: If you have had an introductory Psychology course, and perhaps even if you have not yet, you are likely aware of the challenges faced when researchers and clinicians want to introduce drugs in to specific brain regions or to influence specific neurotransmitter systems within the brain. Trying to increase the functional levels of a neurotransmitter, say serotonin, in a specific system within the brain, say the mood management system, could be tried by pumping a synthetic version of the neurotransmitter substance into body generally. Olive Sacks (as described in his book Awakenings and in the film by the same name where Sacks was played by Robin Williams) did that with L-dopa, a substance the acts like dopamine with patients infected with sleeping sickness (Encephalitis Lethargica) but the effect was temporary due to the system adapting to the new levels of dopamine-like substances and by the many systems within the brain the work with dopamine. The general, difficult to manage effects of drugs like LSD which mimic neurotransmitters and influence vast numbers of brain areas also reflect aspects of this challenge. Likewise, if the goal is to get a therapeutic substance, say a chemotherapy drug, into a very specific area of the brain then the challenge is to get the drug past the blood-brain-barrier (BBB) and into just the targeted brain area in sufficient quantity to have the desired therapeutic impact. Sure, one could inject it directly into the brain but that involves breaching the BBB and the skull and some parts of the brain to get to where the treatment is needed. What to do? Well, I will not ask you to guess as the possible solution was not something I would have come up and I suspect the same is true for you. So, have a look through the article linked below and perhaps at the abstracts of one or two of those in the Further Reading list below to become informed about this amazing emerging procedure.
Source: Fan, C. H., & Yeh, C. K. (2014). Microbubble-enhanced focused ultrasound-induced blood–brain barrier opening for local and transient drug delivery in central nervous system disease. Journal of Medical Ultrasound, 22(4), 183-193.
Date: October 23, 2020
So, it sounds like serios science fiction, right? Introduce a solution containing micro-bubbles and then using an MRI to help target your work you hit the bubbles with a tight ultrasound stream and make a small area of the BBB temporarily permeable allowing a therapeutic substance to get into a very specific area of the brain. Developers suggest it could be useful in the delivery of treatments for Parkinson’s disease, Alzheimer’s, and a range of brain cancers. Cool stuff!
Questions for Discussion:
- Why are disorders linked to very specific brain areas hard to treat even when we are pretty sure we have drugs that would help?
- How does the focused ultrasound procedure work in creating temporary BBB (blood-brain barrier) permeability?
- What other disorders or conditions might see increases in their treatability with this focused ultrasound procedure?
References (Read Further):
Allan C. (2007). Awakenings. BMJ : British Medical Journal, 334(7604), 1169. Link
Chen, K. T., Wei, K. C., & Liu, H. L. (2019). Theranostic strategy of focused ultrasound induced blood-brain barrier opening for CNS disease treatment. Frontiers in pharmacology, 10, 86. Link
Legon, W., Adams, S., Bansal, P., Patel, P. D., Hobbs, L., Ai, L., … & Gillick, B. T. (2020). A retrospective qualitative report of symptoms and safety from transcranial focused ultrasound for neuromodulation in humans. Scientific reports, 10(1), 1-10. Link
Schlesinger, I., Sinai, A., & Zaaroor, M. (2017). MRI-guided focused ultrasound in Parkinson’s disease: a review. Parkinson’s Disease, 2017. Link
Miller, D. B., & O’Callaghan, J. P. (2017). New horizons for focused ultrasound (FUS)–therapeutic applications in neurodegenerative diseases. Metabolism, 69, S3-S7. Link
Ji, R., Smith, M., Niimi, Y., Karakatsani, M. E., Murillo, M. F., Jackson-Lewis, V., … & Konofagou, E. E. (2019). Focused ultrasound enhanced intranasal delivery of brain derived neurotrophic factor produces neurorestorative effects in a Parkinson’s disease mouse model. Scientific Reports, 9. Link