The Neurocritic (the blog) began 9 years ago today.
I've enjoyed the journey immensely and look forward to the years to come, by Nodes of Ranvier (the band — not the myelin sheath gaps).
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Deconstructing the most sensationalistic recent findings in Human Brain Imaging, Cognitive Neuroscience, and Psychopharmacology
“It is feasible to recruit and retain a cohort of female participants to perform a functional magnetic resonance imaging [fMRI] task focused on making decisions about sex, on the basis of varying levels of hypothetical sexual risk, and to complete longitudinal prospective diaries following this task. Preliminary evidence suggests that risk level differentially impacts brain activity related to sexual decision making in these women [i.e., girls aged 14-15 yrs], which may be related to past and future sexual behaviors.”
-Hensel et al. (2015)
Panel (A) provides the average likelihood of young women's endorsing low- and high-risk decisions in the boy, alcohol, food, and household item (control) stimulus categories.
Neural activity in a cognitive-affective network, including prefrontal and anterior cingulate (ACC) regions, was significantly greater during low-risk decisions.
Compared with other decisions, high-risk sexual decisions elicited greater activity in the anterior cingulate, and low-risk sexual decision elicited greater activity in regions of the visual cortex.
Specifically, we hypothesized that learning a negative affective story during the reconsolidation window compared to no interference would interfere with the reconsolidation of memories of the Boston Marathon bombings. In addition, we expected the neutral and positive stories to result in some interference, but not as much as the negative story.
...represent[s] a step toward translating reconsolidation interference work to the clinic, as, to our knowledge, no published studies to date have examined nonpharmacological reconsolidation interference for clinically-relevant negative memories. Additional studies should examine reconsolidation interference paradigms, such as this one, in clinical populations.
...some degree of similarity between the original memory and interference task may be required to achieve interference effects. This is in line with research suggesting that external and internal context is an important factor in extinction learning and may also be relevant to reconsolidation. As such, activating the affective context in which a memory was originally consolidated may facilitate reconsolidation interference.This is a very different strategy than the “updating of fear memories” approach, where a safety signal occurs before extinction. But conditioned fear (blue square paired with mild shock) is very different from episodic memories of a bombing scene.
A group consensus coding system was used to code the memories. S1 and S2 memory descriptions for each participant were compared and coded for recall of memory details. One point was given for each detail from the S1 memory description that was recalled in the S2 memory description. Each memory pair was coded by between three to five raters until a consensus between three raters was reached. Raters were blind to participant randomization, but not to each other's ratings. Consensus was reached in 83% of memory pairs.
Blown-up brains reveal nanoscale details
Material used in diaper absorbant can make brain tissue bigger and enable ordinary microscopes to resolve features down to 60 nanometres.
Microscopes make living cells and tissues appear bigger. But what if we could actually make the things bigger?
It might sound like the fantasy of a scientist who has read Alice’s Adventures in Wonderland too many times, but the concept is the basis for a new method that could enable biologists to image an entire brain in exquisite molecular detail using an ordinary microscope, and to resolve features that would normally be beyond the limits of optics.
The technique, called expansion microscopy, involves physically inflating biological tissues using a material more commonly found in baby nappies (diapers).
“What we’ve been trying to do is figure out if we can make everything bigger,” Boyden told the meeting at the NIH in Bethesda, Maryland. To manage this, his team used a chemical called acrylate that has two useful properties: it can form a dense mesh that holds proteins in place, and it swells in the presence of water.
Sodium polyacrylate (via Leonard Gelfand Center, CMU)
Acrylate, a type of salt also known as waterlock, is the substance that gives nappies their sponginess. When inflated, Boyden's tissues grow about 4.5 times in each dimension.
Just add water
Before swelling, the tissue is treated with a chemical cocktail that makes it transparent, and then with the fluorescent molecules that anchor specific proteins to the acrylate, which is then infused into tissue. Just as with nappies, adding water causes the acrylate polymer to swell. After stretching, the fluorescent-tagged molecules move further away from each other; proteins that were previously too close to distinguish with a visible-light microscope come into crisp focus. In his NIH presentation, Boyden suggested that the technique can resolve molecules that had been as close as 60nm before expansion.
Gosh. That clever @eboyden3 has figured out how to blow up brains http://t.co/G8C17w3Uo0
— Roger Highfield (@RogerHighfield) January 9, 2015
After the second interim analysis, the trial was stopped because of futility. For the primary hypothesis comparing progesterone with placebo, favorable outcomes occurred in 51.0% of patients assigned to progesterone and in 55.5% of those assigned to placebo.
The PROTECT III trial joins a growing list of negative or inconclusive trials in the arduous search for a treatment for TBI. To date, more than 30 clinical trials have investigated various compounds for the treatment of acute TBI, yet no treatment has succeeded at the confirmatory trial stage. Many reasons for the disappointing record of translating promising agents from the laboratory to the clinic have been postulated, including limited preclinical development work, poor drug penetration into the brain, delayed initiation of treatment, heterogeneity of injuries, variability in routine patient care across sites, and insensitive outcome measures.
The negative result of this study, combined with the results of the PROTECT III trial, should stimulate a rethinking of procedures for drug development and testing in TBI.
$17M DoD Award Aims to Improve Clinical Trials for Traumatic Brain Injury
An unprecedented, public-private partnership funded by the Department of Defense (DoD) is being launched to drive the development of better-run clinical trials and may lead to the first successful treatments for traumatic brain injury, a condition affecting not only athletes and members of the military, but also millions among the general public, ranging from youngsters to elders.
Under the partnership, officially launched Oct. 1 with a $17 million, five-year award from the DoD, the research team, representing many universities, the Food and Drug Administration (FDA), companies and philanthropies, will examine data from thousands of patients in order to identify effective measures of brain injury and recovery, using biomarkers from blood, new imaging equipment and software, and other tools.
. . .
“TBI is really a multifaceted condition, not a single event,” said UCSF neurosurgeon Geoffrey T. Manley, MD, PhD, principal investigator for the new award... “TBI lags 40 to 50 years behind heart disease and cancer in terms of progress and understanding of the actual disease process and its potential aftermath. More than 30 clinical trials of potential TBI treatments have failed, and not a single drug has been approved.”
“Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements.”
-Yamao et al. (2014)
The coordination of human laughter involves the periaqueductal grey [PAG] and the reticular formation [RF], with inputs from cortex, the basal ganglia, and the hypothalamus. The hypothalamus is more active during reactive laughter than during voluntary laughter. Motor and premotor cortices are involved in the inhibition of the brainstem laughter centres and are more active when suppressing laughter than when producing it.
During gelastic seizures, some patients report pleasant feelings which include exhilaration or mirth. Other patients experience the attacks of laughter as inappropriate and feel no positive emotions during their laughter. It has been claimed that gelastic seizures originating in the temporal regions involve mirth but that those originating in the hypothalamus do not. This claim has been called into question, however...
...the ratio of electrodes eliciting language impairment was higher for the mirth electrodes than in no-mirth electrodes, suggesting an association between mirth and language function. Since the BTLA is actively involved in semantic processing (Shimotake et al., 2014 and Usui et al., 2003), this semantic/language area was likely involved in the semantic aspect of humor detection in our cases.
"Electrical stimulation of the left basal temporal cortex elicits mirth and laughter" in humans http://t.co/f32uclnlFh TemporLOL cortex
— Neuroskeptic (@Neuro_Skeptic) December 24, 2014
Don’t worry, be happy: just go to bed earlier
When you go to bed, and how long you sleep at a time, might actually make it difficult for you to stop worrying. So say Jacob Nota and Meredith Coles of Binghamton University in the US, who found that people who sleep for shorter periods of time and go to bed very late at night are often overwhelmed with more negative thoughts than those who keep more regular sleeping hours.
“Making sure that sleep is obtained during the right time of day may be an inexpensive and easily disseminable intervention for individuals who are bothered by intrusive thoughts,” remarks Nota.
The findings also suggest that sleep disruption may be linked to the development of repetitive negative thinking. Nota and Coles therefore believe that it might benefit people who are at risk of developing a disorder characterized by such intrusive thoughts to focus on getting enough sleep.
“If further findings support the relation between sleep timing and repetitive negative thinking, this could one day lead to a new avenue for treatment of individuals with internalizing disorders,” adds Coles. “Studying the relation between reductions in sleep duration and psychopathology has already demonstrated that focusing on sleep in the clinic also leads to reductions in symptoms of psychopathology.”
This Sleep Tweak Could Help You Worry Less
Can the time you hit the hay actually influence the types of thoughts you have? Science says yes.
Are you a chronic worrier? The hour you’re going to sleep, and how much sleep you’re getting overall, may exacerbate your anxiety, according to a new study published in the journal Cognitive Therapy and Research.
The great news here? By tweaking your sleep habits you could actually help yourself worry less. Really.