Brainbabble
Enjoy --
Stressed Kris
A while back, I read an online discussion on the evolution of the ego. What?! How can a construct evolve? although the concept of the ego may be a useful in the context of psychodynamic therapy, it has no place in the theory of evolution. Before you Freudians get upset, let me explain.  First, we all know that Darwinian evolutionary theory works through “survival of the fittest”. This simply means that those who procreate pass on their genes, and those who do not successfully procreate don’t pass their genes on to the next generation. As simple as this concept is, many have difficulty understanding the implications. It has nothing to do with ego, especially in the pop-culture sense, e.g. to “boost one’s ego” (morale, happiness, other fuzzy hard-to-define constructs).
From my perspective, which certainly is not an original perspective, the collection of cognitive & emotional processes that contribute to the popular construct known as the “ego” developed because they gave an advantage to those who possessed them. For example, the sense of self that can be observed even in a very young child when s/he looks into a mirror may have been a byproduct of other advantageous traits. The evolution of consciousness (not conscience!) allowed the “ego” to develop in the human race. Simple as that!
Check out this interesting article.
Chicks Have Superior Brain Activity Before Hatching
Researchers from Carlos III Univ. in Madrid (UC3M) are part of a team that, for the first time ever, has been able to monitor the brain activity of a chicken embryo and to confirm that superior brain activity (carrying out complex tasks) begins long before the chick hatches.
This is one of the principle conclusions of a study that has been published in the scientific journal Current Biology. Participants in the study included Evan Balaban (McGill Univ., Montreal), Manuel Desco (Gregorio Marañón General Univ. Hospital of Madrid and UC3M) and Juan José Vaquero (UC3M). The researchers managed to arouse a chicken embryo by exposing it to a sound that would have meaning after its birth (for example, the sound of a chicken warning others of danger). However, their study has demonstrated that the animal does not have the same reaction when it is exposed to a sound that is similar, but that has no special meaning for the chick.
Read more: http://www.laboratoryequipment.com/news-Chicks-Have-Superior-Brain-Activity-Before-Hatching-051512.aspx
Sanitation. By Spider Tribal Arts.
“If you have a garden and a library, you have everything you need.” Cicero’s timeless words in a typographic print, reminiscent of the lovely Live Now project.
What are the effects of stress & adversity on the brain that affect well-being? A recent review by Davidson & McEwen in Nature Neuroscience (“Social influences on neuroplasticity: stress and interventions to promote well-being”) explores this question. One interesting aspect about research on the relationship between the brain and “happiness” or “well-being” is how we operationally define these constructs. Most of us “know” what “happiness” is - or do we? What about well-being? Interestingly, Davidson & McEwen do not define well-being in this review; they assume we all agree on what it is.
Assuming that we all agree on what well-being is, the review summarizes animal and human research on the effects of stress on the brain and on social/emotional functioning. We know that chronic stress reduces dendritic branching in the medial prefrontal cortex and hippocampus, while it increases branching in orbitofrontal cortex and amygdala. These regions are important for emotional and social behavior, and Davidson & McEwen propose that they are important for well-being. The effects they summarize on dendritic branching in these regions are reversible, especially in children, so perhaps therapies that lead to a better sense of well-being are, at least in part, acting through these brain regions/circuits.
Early life stress is a particularly extraordinary example of how experience influences brain structure and function in ways that can have devastating effects on how a child is able to function in the world. But the hopeful message of this review is that, even though the horrible stress of child abuse has detrimental effects on a child’s brain, these effects should be at least partly reversible, based on animal research. The positive effects found following intervention programs that address emotional and social functioning in school-aged children reflect changes in brain structure and function.
[http://brainimaging.waisman.wisc.edu/publications/2012/DavidsonSocialNN.pdf]
Chronic stress causes neurons to shrink or grow, but not necessarily to die. Representation of the chronic stress effects detected in animal models on growth or retraction of dendrites in the basolateral amygdala and orbitofrontal cortex (growth) and in the CA3 hippocampus, dentate gyrus and medial prefrontal cortex (shrinkage). These effects are largely reversible in young adult animals, although aging appears to compromise resilience and medial prefrontal cortex recovery. From Davidson & McEwen (2012) doi:10.1038/nn.3093
Elevated stress hormones in pregnant women lead to larger amygdala volume in girls, and to more emotional problems as well. The emotional problems are mediated by amygdala volume.
A recent article in PNAS by Claudia Buss and colleagues [Maternal cortisol over the course of pregnancy and subsequent child amygdala and hippocampus volumes and affective problems] reports that mother’s stress during pregnancy has long-term consequences on the child’s brain development and subsequent emotional development.
Indications of this has been apparent from the animal literature for a long time, but this longitudinal study periodically assessed salivary cortisol in pregnant women and followed the children until age 7, when the researchers took MRIs of the children’s brains and assessed their affective problems. From the MRIs, amygdala and hippocampal volumes were calculated. Higher cortisol levels in the mothers during early pregnancy, but not later pregnancy, was associated with larger amygdala volumes and greater affective problems in girls but not boys. The affective problems were mediated by amygdala size.
This study appears to be the first that shows this relationship in humans. When the mother experiences stress, cortisol is released her body and can enter the fetus. Through this association, brain structure is affected. In adults, the amygdala is implicated in mood and anxiety disorders and in emotional behavior — for example, when a person is depressed, cortisol may affect amygdala activity which may in turn influence cognitive and emotional processing. Perhaps this process (prenatal stress affecting amygdala structure) contributes to the increased rates of depression in children from low socioeconomic households.
But why only in girls? That’s very interesting.
