Neurology
It May Look Like I’m Not Doing Anything But I’m Actually in Default Mode
The default mode was one of the first brain networks characterized by science. It consists of a handful of brain regions, including a few at the front of the brain, like the dorsal and ventral medial prefrontal cortices, and others scattered throughout the organ, like the posterior cingulate cortex, the precuneus and the angular gyrus. These regions are associated with memory, experience replay, prediction, action consideration, reward/punishment and information integration…
According to research, the effects of the default mode network include mind wandering, remembering past experiences, thinking about others’ mental states, envisioning the future and processing language. While this may seem like a grab bag of unrelated aspects of cognition, Vinod Menon, the director of the Stanford Cognitive & Systems Neuroscience Laboratory, recently theorized that all of these functions may be helpful in constructing an internal narrative. In his view, the default mode network helps you think about who you are in relation to others, recall your past experiences and then wrap up all of that into a coherent self-narrative.
What Your Brain Is Doing When You’re Not Doing Anything — https://www.quantamagazine.org/what-your-brain-is-doing-when-youre-not-doing-anything-20240205
Great article.
But Both Are Legal…right? – Updated
“We found that alcohol and THC together significantly reduced, and in some cases prevented, the ability of the prefrontal cortex in drug-exposed rats to undergo plasticity in the same way that the brains from control animals can,” said Linyuan Shi, a graduate student in the Gulley lab. “The effects were apparent in rats exposed to either drug alone, and they were most pronounced with co-exposure to both drugs. We also found the impaired plasticity was likely due to changes in signaling caused by gamma-aminobutyric acid, a chemical messenger in the brain. When we used a chemical that enhances GABA, it could rescue the deficits we saw in the animals that had been exposed to the drugs.”
Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign. “Combined use of alcohol and THC can affect rat brains, study finds.” ScienceDaily. ScienceDaily, 30 November 2023 — https://www.sciencedaily.com/releases/2023/11/231130121946.htm
I’m glad I am not a rat.
Young adults who simultaneously use alcohol and marijuana (SAM) consume more drinks, are high for more hours in the day, and report more negative alcohol-related consequences.
On SAM use days, participants consumed an average of 37% more drinks, with 43% more negative alcohol consequences, were high for 10% more hours, and were more likely to feel clumsy or dizzy, compared with non-SAM use days.
Simultaneous Marijuana, Alcohol Use Linked to Worse Outcomes — https://www.medscape.com/viewarticle/996595?icd=login_success_gg_match_norm&isSocial
Hmmm…
But Both Are Legal…right?
“We found that alcohol and THC together significantly reduced, and in some cases prevented, the ability of the prefrontal cortex in drug-exposed rats to undergo plasticity in the same way that the brains from control animals can,” said Linyuan Shi, a graduate student in the Gulley lab. “The effects were apparent in rats exposed to either drug alone, and they were most pronounced with co-exposure to both drugs. We also found the impaired plasticity was likely due to changes in signaling caused by gamma-aminobutyric acid, a chemical messenger in the brain. When we used a chemical that enhances GABA, it could rescue the deficits we saw in the animals that had been exposed to the drugs.”
Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign. “Combined use of alcohol and THC can affect rat brains, study finds.” ScienceDaily. ScienceDaily, 30 November 2023 — https://www.sciencedaily.com/releases/2023/11/231130121946.htm
I’m glad I am not a rat.
Sedentary Behavior and Incident Dementia Among Older Adults
Conclusions and Relevance Among older adults, more time spent in sedentary behaviors was significantly associated with higher incidence of all-cause dementia. Future research is needed to determine whether the association between sedentary behavior and risk of dementia is causal.
Sedentary Behavior and Incident Dementia Among Older Adults — https://jamanetwork.com/journals/jama/article-abstract/2809418
I’m screwed.
Social isolation and Lower Brain Volume
The people with the lowest amount of social contact had overall brain volume that was significantly lower than those with the most social contact. The total brain volume, or the sum of white and grey matter, as a percentage of the total intracranial volume, or the volume within the cranium, including the brain, meninges, and cerebrospinal fluid, was 67.3% in the lowest contact group compared to 67.8% in the highest contact group. They also had lower volumes in areas of the brain such as the hippocampus and amygdala that play a role in memory and are affected by dementia.
The study does not prove that social isolation causes brain shrinkage; it only shows an association.
Social isolation linked to lower brain volume — American Academy of Neurology. “Social isolation linked to lower brain volume.” ScienceDaily https://www.sciencedaily.com/releases/2023/07/230712165229.htm (accessed July 13, 2023).
Yikes!
Take Your Vitamins
In the current study, more than 3,500 adults (mostly non-Hispanic white) over age 60 were randomly assigned to take a daily multivitamin supplement or placebo for three years. At the end of each year, participants performed a series of online cognitive assessments at home designed to test memory function of the hippocampus, an area of the brain that is affected by normal aging. The COSMOS-Web study is part of a large clinical trial led by Brigham & Women’s Hospital and Harvard called the COcoa Supplement and Multivitamin Outcomes Study (COSMOS).
By the end of the first year, memory improved for people taking a daily multivitamin, compared with those taking a placebo. The researchers estimate the improvement, which was sustained over the three-year study period, was equivalent to about three years of age-related memory decline. The effect was more pronounced in participants with underlying cardiovascular disease.
Columbia University Irving Medical Center. “Multivitamin improves memory in older adults, study finds.” ScienceDaily. http://www.sciencedaily.com/releases/2023/05/230524181916.htm (accessed May 25, 2023).
Take a Break – 04.19.23 (let’s do some brain remodeling)
A study led by the UNIGE, HES-SO Geneva, and EPFL revealed that music practice and active listening could prevent working memory decline. Such activities promoted brain plasticity, they were associated with grey matter volume increase. Positive impacts have also been measured on working memory. This study was conducted among 132 healthy retirees from 62 to 78 years of age. One of the conditions for participation was that they had not taken any music lessons for more than six months in their lives…The participants were randomly assigned to two groups, regardless of their motivation to play an instrument. The second group had active listening lessons, which focused on instrument recognition and analysis of musical properties in a wide range of musical styles. The classes lasted one hour. Participants in both groups were required to do homework for half an hour a day.”
After six months, we found common effects for both interventions. Neuroimaging revealed an increase in grey matter in four brain regions involved in high-level cognitive functioning in all participants, including cerebellum areas involved in working memory. Their performance increased by 6% and this result was directly correlated to the plasticity of the cerebellum,” says Clara James, last author of the study, a privat-docent at the Faculty of Psychology and Educational Sciences of UNIGE, and full professor at the Geneva School of Health Sciences
Université de Genève. “How music can prevent cognitive decline.” ScienceDaily. http://www.sciencedaily.com/releases/2023/04/230417142520.htm (accessed April 18, 2023).
Journal Reference – Damien Marie, Cécile A.H. Müller, Eckart Altenmüller, Dimitri Van De Ville, Kristin Jünemann, Daniel S. Scholz, Tillmann H.C. Krüger, Florian Worschech, Matthias Kliegel, Christopher Sinke, Clara E. James. Music interventions in 132 healthy older adults enhance cerebellar grey matter and auditory working memory, despite general brain atrophy. Neuroimage: Reports, 2023; 3 (2): 100166 DOI: 10.1016/j.ynirp.2023.100166
I could feel my brain grey matter volume increasing when listening to this album.
People who think positively about aging are more likely to recover memory
A new study has found that older persons with mild cognitive impairment (MCI), a common type of memory loss, were 30% more likely to regain normal cognition if they had taken in positive beliefs about aging from their culture, compared to those who had taken in negative beliefs.
Yale School of Public Health. “People who think positively about aging are more likely to recover memory.” ScienceDaily. http://www.sciencedaily.com/releases/2023/04/230412131116.htm (accessed April 18, 2023).
Journal Reference – Becca R. Levy, Martin D. Slade. Role of Positive Age Beliefs in Recovery From Mild Cognitive Impairment Among Older Persons. JAMA Network Open, 2023; 6 (4): e237707 DOI: 10.1001/jamanetworkopen.2023.7707
I cannot believe how wonderful the aging process is said no one ever.
Dieting: Brain amplifies signal of hunger synapses (in mice)
The researchers put mice on a diet and assessed which circuits in the brain changed. In particular, they examined a group of neurons in the hypothalamus, the AgRP neurons, which are known to control the feeling of hunger. They were able to show that the neuronal pathways that stimulate AgRP neurons sent increased signals when the mice were on a diet. This profound change in the brain could be detected for a long time after the diet.
Max Planck Institute for Biology of Ageing. “Dieting: Brain amplifies signal of hunger synapses: Possible target for drugs to combat the yo-yo effect.” ScienceDaily. http://www.sciencedaily.com/releases/2023/03/230324135218.htm (accessed March 28, 2023).
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