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July 2024: A Month in Review of Neuroscience News Articles Referring to Original Research


Over the last month, many online news articles have drawn our attention to neuroscience-related topics and research. If it exists, I prefer to refer to the original research to interpret such news articles' real significance and claims. The overlapping themes for this month include Dementia (novel drug treatment, lifestyle changes as treatment, machine learning for prediction, and benzodiazepine use), Mood disorders (brain signatures of depression subtypes, and brain areas involved with mood swings in bipolar), and Dopamine (social understanding, reward from pornography).


Dementia


In this last month's research, Dementia has been a frequent topic. Hart et al. (2024) conducted a study in those with Lewy Body Dementia using alpha-1 adrenoreceptor antagonists that stimulate ATP glycolysis, which is involved in energy production. It was hypothesized that this might slow the degenerative brain process that leads to alpha-synuclein, the protein that makes up Lewy bodies. Men taking these drugs were less likely to develop LBs.

In the Harvard Gazette, there was an article titled, "Alzheimer's study finds diet, lifestyle changes yield improvements" (Powell, 2024). In the original study by Ornish et al., (2024) they examined 49 participants with suspected early AD (mean age = 73.5) with half in the intervention group using various cognitive measures and physiological measures (i.e., beta-amyloid) while making various lifestyle changes (diet, exercise, group support, dietary supplements) over 20 weeks versus the other half as the control group. These lifestyle changes in the intervention group, versus the control group, resulted in a significant improvement in cognition.   

Another article mentioned machine learning to predict dementia up to nine years prior to diagnosis (Dolan, 2024a). The original study by Ereira et al. (2024) examined functional connectivity (between brain regions) in the default mode network (DMN) which tends to be active when we are not actively engaged in any task. The study employed dynamic causal modeling (machine learning) to examine this resting state functional connectivity MRI (rs-fcMRI) from a database to follow 1,111 participants. Eighty-one of these participants subsequently developed dementia within 9 years, leaving the remaining 1,030 participants to be a retrospective control group. Measures of "dysconnectivity" were significantly greater in the dementia group for their resting state DMN. The authors stated that they also examined social isolation and polygenic risk for AD.

The final article related to dementia was about how the long-term use of benzodiazepines (BZDs) was associated with a decrease in brain volume in specific brain areas (Cooke, 2024). The original study by Hofe et al. (2024) employed 5,543 participants without cognitive impairment (an MMSE score of 26 or greater) taken from the Rotterdam study database (57.4% women, mean age 70.6 years). The use of BZDs was derived from pharmacy records. 4,836 participants conducted repeated MRIs with BZD usage as a regressor. Nearly 50% of these participants had used BZDs prior to baseline (within a 15-year period) with 13.3 % (n = 726 developed dementia) at a mean of 11 years post baseline. The risk appeared to be highest for those taking BZDs for anxiety. Current use of BZDs were correlated with brain volume reduction in multiple areas (hippocampi, amygdalae, and thalamus). The authors made sure to state that this was not associated with BDZ use alone but with those using BZDs as anxiolytics. This appears to suggest a connection with the treatment of anxiety disorders instead of insomnia.


Mood disorders

Research on mood disorders was also in the news over the last month. One article mentioned distinct brain endophenotypes for subtypes of depression (Dolan, 2024b). The original study by Tozzi et al (2024) examined 801 patients with untreated depression and anxiety prior to placement in a study using either medication or psychotherapy. The psychotherapy group consisted of 250 patients. fcMRI was used to examine the various brain networks including the default mode, salience, and attentional with regressors from cognitive and emotion-eliciting tasks. This resulted in six distinct subtypes that correlated with brain activation and their best treatment interventions. The details are too extensive here to review. Please follow the links to the news article and the original study from the reference section below.

Next, there was a news article about the brain areas associated with mood shifts or dysregulated mood, in bipolar disorder Moningka (2024). Of note, the news article was written by the first author of the published study (Moningka & Mason 2024). In the original study, the authors theorized a connection between dysregulated mood and the misperception of rewards in 21 patients with bipolar disorder versus 21 control participants. Those with bipolar disorder had "momentum-biased reward prediction errors" associated with changes in the striatum, a brain area associated with reward. Thus, these misperceptions in bipolar disorder appear to be associated with reward brain areas and possibly mood dysregulation.


Dopamine


The first news article related to dopamine connected it to social understanding and theory of mind (Schuster & Cook, 2024). As in the previous section, the news article was written by two authors of the original study (Schuster et al., 2024). The authors stated differences in theory of mind are seen in those with dopaminergic disorders (i.e., PD). In this study, the researchers used a double-blind, placebo-controlled experiment (DA antagonism with haloperidol) paired with a test related to theory of mind (mental attribution) in normal volunteers. Participants completed test-retest with the order of haloperidol and placebo randomized at the individual level. The accuracy of deriving mental state from the task was significantly impaired in those in the haloperidol condition versus placebo. The researchers concluded that dopamine played a role in theory of mind.

In the next news article, it was stated that pornography was more rewarding, via brain DA, than money or gaming (Dolan 2024c). The original study by Krikova et al. (2024) employed 31 participants (all right-handed males, age range of 19-38) with a task consisting of images (self-selected and rated by participants in terms of arousal and valence and

prior to the experiment from three categories: pornography, gaming, and money) with concurrent fMRI. Brain activation, bilaterally in the nucleus accumbens (a region innervated by DA and associated with reward) the right medial orbitofrontal cortex, and the right ventral anterior cingulate, was significantly greater for pornography.



Abbreviations in this blog:

AD: Alzheimer's disease

ATP: adenosine triphosphate

BZD(s): benzodiazepine(s)

DA: dopamine DMN: default mode network

fMRI: functional magnetic resonance imaging

LBs: Lewy bodies

MMSE: Mini Mental State Examination

PD: Parkinson's disease

rs-fcMRI: resting state functional connectivity magnetic resonance imaging


References






  • Ereira, S., Waters, S., Razi, A., & Marshall, C. R. (2024). Early detection of dementia with default-mode network effective connectivity. Nature Mental Health, 2(7), 787–800. https://doi.org/10.1038/s44220-024-00259-5

  • Hart, A., Aldridge, G., Zhang, Q., Narayanan, N. S., & Simmering, J. E. (2024). Association of terazosin, doxazosin, or alfuzosin use and risk of dementia with Lewy bodies in men. Neurology, 103(2). https://doi.org/10.1212/wnl.0000000000209570


  • Hofe, I. vom, Stricker, B. H., Vernooij, M. W., Ikram, M. K., Ikram, M. A., & Wolters, F. J. (2024). Benzodiazepine use in relation to long-term dementia risk and imaging markers of neurodegeneration: A population-based study. BMC Medicine, 22(1). https://doi.org/10.1186/s12916-024-03437-5


  • Krikova, K., Klein, S., Kampa, M., Walter, B., Stark, R., & Klucken, T. (2024). Appetitive conditioning with pornographic stimuli elicits stronger activation in reward regions than monetary and gaming‐related stimuli. Human Brain Mapping, 45(8). https://doi.org/10.1002/hbm.26711



  • Moningka, H., & Mason, L. (2024). Misperceiving momentum: Computational mechanisms of biased striatal reward prediction errors in bipolar disorder. Biological Psychiatry Global Open Science, 4(4), 100330. https://doi.org/10.1016/j.bpsgos.2024.100330

  • Ornish, D., Madison, C., Kivipelto, M., Kemp, C., McCulloch, C. E., Galasko, D., Artz, J., Rentz, D., Lin, J., Norman, K., Ornish, A., Tranter, S., DeLamarter, N., Wingers, N., Richling, C., Kaddurah-Daouk, R., Knight, R., McDonald, D., Patel, L., … Arnold, S. E. (2024). Effects of intensive lifestyle changes on the progression of mild cognitive impairment or early dementia due to alzheimer’s disease: A randomized, controlled clinical trial. Alzheimer’s Research & Therapy, 16(1). https://doi.org/10.1186/s13195-024-01482-z




  • Schuster, B. A., Sowden, S., Rybicki, A. J., Fraser, D. S., Press, C., Hickman, L., Holland, P., & Cook, J. L. (2024). Disruption of dopamine D2/D3 system function impairs the human ability to understand the mental states of other people. PLOS Biology, 22(6). https://doi.org/10.1371/journal.pbio.3002652

  • Tozzi, L., Zhang, X., Pines, A., Olmsted, A. M., Zhai, E. S., Anene, E. T., Chesnut, M., Holt-Gosselin, B., Chang, S., Stetz, P. C., Ramirez, C. A., Hack, L. M., Korgaonkar, M. S., Wintermark, M., Gotlib, I. H., Ma, J., & Williams, L. M. (2024). Personalized brain circuit scores identify clinically distinct biotypes in depression and anxiety. Nature Medicine, 30(7), 2076–2087. https://doi.org/10.1038/s41591-024-03057-9



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