English (United Kingdom)French (Fr)Russian (CIS)Espa
Home Forum Neurohacking The Lab Tutorial 14 potential hiccup

Login

      
      |
If you want to register, please send a mail introducing yourself to nha.council at our domain name (omitting the "www" of course).

Act2Ally
useravatar
User Info

Tutorial 14 potential hiccup

It reads: "Experiments show that severe and/or prolonged stress (anxiety) is associated with a glutamate-induced elevation of brain-derived neurotrophic factor (BDNF)[...]"

but then a mere couple paragraphs later: "An excess of glutamate causes reduced BDNF and shrinkage of dendrites, [97...]"

What gives?! ò.ó'

A2A


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Tutorial 14 potential hiccup

Hi dude, sorry for delay.
Long mail; get tea  :  )

This is in reference to burnout, where levels of neurochemicals and number of functional receptors tend to increase up to a critical mass where the burnout occurs, and then plummet below 'normal' levels. This pattern, where (for example) elevated cortisol followed by big reductions in cortisol, is indicative of burnout. A regular case of excess of anything will cause temporary down-regulation of receptors, but in burnout there is more widespread down-regulation which may if not adjusted be permanent. In some cases certain areas are initially up-regulated at the expense of others.

From the original paper:
Interestingly, in the amygdala, stress seems to lead to an increase in neurotrophic factors such as BDNF, and to enhance dendritic outgrowth. In the functional and anatomical projection areas of the amygdala, the stress-related glutamatergic excess is, on the other hand, reported to lead to reduced BDNF and shrinkage of dendrites (Arendt et al. 2012; Boyle 2013). These degenerative events are particularly pronounced in the mPFC (Roozendaal et al. 2004; Brown et al. 2005; Radley et al. 2008; Arnsten 2009; Leuner and Shors 2012).

This is of interest because the mPFC exerts a strong negative control over stress pathways. GABAergic signals from the mPFC to the amygdala lead to a repression of the HPA axis. This provides a basis for one possible scenario for the present condition, in which stress-mediated neurotoxic damage to the mPFC, due to high glutamate, cortisol, or the combination of both (see Magarinos and McEwen 1995), has led to impaired prefrontal inhibition of the amygdala (Roozendaal et al. 2004). This would then have provided a context for a vicious circle with a further enhancement of amygdala excitation and subsequent changes along the networks connected to the amygdala (the mPFC, the basal ganglia, the hippocampus, and the insular, anterior cingulate, and orbitofrontal cortices).

The presently reported findings among subjects suffering from occupational stress fit into this model, with the increase in amygdala volume and reduction in caudate volume, the thinning of the mPFC, and the more pronounced cortico-cortical covariation between the mPFC and insular cortex (Wang et al. 2007; Liston et al. 2009; Goldstein et al. 2010). It is also compatible with the notion that both the putamen and caudate receive powerful glutamatergic input from the amygdala (McEwen 2000b) and are susceptible to excitotoxicity (Chen et al. 1995; Bernal et al. 2000). This strengthens reiterating the hypothesis presented in our initial stress-related publication (Jovanovic et al. 2011) that repeated stress stimuli could cause excitotoxic, apoptotic, and/or intermediate forms of neuronal death (Bengzon et al. 1997) with atrophy in humans.


Here is one of the original papers:
http://cercor.oxfordjournals.org/conten … ull#ref-12


There has been more recent discovery in the field of synaptic plasticity which is relevant to the above in context of altered BDNF levels:

DOI: 10.1038/nature19766/10.1038/nature19784 Stephen C. Harward et al. Autocrine BDNF–TrkB signalling within a single dendritic spine, Nature (2016). DOI: 10.1038/nature19766

Nathan G. Hedrick et al. Rho GTPase complementation underlies BDNF-dependent homo- and heterosynaptic plasticity, Nature (2016). DOI: 10.1038/nature19784 

"Two new studies uncover key players responsible for learning and memory formation" October 3, 2016 http://medicalxpress.com/news/2016-10-uncover-key-players-responsible-memory.html

Best,
AR


Administrator has disabled public posting
Act2Ally
useravatar
User Info

Re: Tutorial 14 potential hiccup

> Hi dude, sorry for delay.

Hi! Thx for replying smile

> Long mail; get tea  :  )

Good idea. Although, what about that data about tea leaves accumulating too much fluoride? marketing? (again lol) or should I say "anti-marketing" marketing (still marketing tho).. 'cause China, for some strange reason, seems to love pumping those teabag papers out.

Alex said:

> Lots

Ok, so if I understand correctly (IIUC?) my confusion arose from the (implicit) assumption that the tutorial would be referring to the same part of the brain.

When in fact it distinguishes "functional and anatomical projection areas of the amygdala" from the amydgala proper.

Right?

thanks! : )
[+]
A2A

PS.: I told u it would take a long time to get to this one.. only now could I come around to begin =) Thx for (was it Sakiro?) tip on reading tho, although I knew how, it seems i can remember even less if I do that way. ;-(


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Tutorial 14 potential hiccup

Yeh this is the fun with brains  :  )
Researchers narrow down an area that appears to be specializing in one or two data types, and think, great, we'll call this part 'the amygdala' (or whatever). Then you go look at what the amygdala is doing, and you find half a dozen different compartments all doing different things, or different bits of the same task... so you select one and think okay, we'll call this part the 'rostral amygdala', and you look at what it's doing, and you find... oh yeh, another little batch of individual parts in there, doing different things...
...I guess we already know that this sort of thing doesn't stop at the atomic level  :  )

Tea in Wonderland:
...“Take some more tea," the March Hare said to Alice, very earnestly.
"I've had nothing yet," Alice replied in an offended tone, "so I can't take more."
"You mean you can't take less," said the Hatter: "it's very easy to take more than nothing."

Best,
AR


Administrator has disabled public posting
Act2Ally
useravatar
User Info

Re: Tutorial 14 potential hiccup

Like Matroskas : ) That's 1 reason I'm with Ramez Naam (and about other controversial CS topics as well, which was quite surprising) about not having much of an optimism about AI soon.. Tho it should at least be useful for some things I guess? :-)

  about tea, there are other metals too, check it out [1] I'd say they accumulate as drags instead of the scum (they should be heavier, I suppose) but I don't quite remember/know and I definitely wanna stay on the safe side regarding any set up that could kill me slowly, lol since they are quite dangerous, not to mention a surprising effect (not sure if the caffeine in the tea? xhantine?) but I kinda worry about snoring and waking people up, not sure of this effect quite yet since I'm sleeping at the time. lol Another deluge of studies/suggestions would be appreciated ^__^ [gave up on that "earthing" thread tho, you're too thorough! haha, awesome! thanks.]

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3821942/


Administrator has disabled public posting
Alex
useravatar
User Info

Re: Tutorial 14 potential hiccup

Tea issues can be solved by DIY:

http://www.camforest.com/category_s/53.htm

(and a whole host of other benefis from gardening activities)
Best,
AR


Administrator has disabled public posting

Board Info

User Info:   Newest User :  outoftheloop   Members Online: 0   Guests Online: 144
Topic
New
Locked
Topic
New
Locked
Sticky
Active
New/Active
Sticky
Active
New/Active
New/Closed
New Sticky
Closed/Active
New/Locked
New Sticky
Locked/Active
Active/Sticky
Sticky/Locked
Sticky Active Locked
Active/Sticky
Sticky/Locked
Sticky/Active/Locked