amygdala

means "almond", so-named because of its shape and size. The amygdala is part of the basal ganglia, and is situated in the temporal lobe. It has many connections with other parts of the brain, most particularly with the limbic system, for which reason it is considered part of the limbic system (although not part of the limbic lobe itself). The amygdala is critically involved in computing the emotional significance of events, and recent research indicates it is responsible for the influence of emotion on perception, through its connections with those brain regions that process sensory experiences, thus "allowing perception of emotionally significant events to occur despite inattention.” Rat studies also suggest that the amygdala, in tandem with the orbitofrontal cortex, is involved in the forming of new associations between cues and outcomes - in other words, it is the work of the amygdala to teach us what happens to us when we do something.

What happens after traumatic brain injury occurs?

December, 2010

Findings from a rat study show how TBI can begin a process that continues to deform the brain long after the original injury.

A rat study using powerful imaging techniques has revealed how an injured brain continues to change long after the original trauma. Widespread decreases in brain functioning over a period of months were seen in specific brain regions, in particular the hippocampus, amygdala, and ipsilateral cortex, even when these were remote from the site of direct trauma and unaccompanied by signs of injury.

The findings indicate that there is a time window during which intervention could reduce these processes and protect against some of the disabling consequences of TBI.

Reference: 

[1988] Liu, Y. R., Cardamone L., Hogan E. R., Gregoire M-C., Williams J. P., Hicks R. J., et al.
(2010).  Progressive Metabolic and Structural Cerebral Perturbations After Traumatic Brain Injury: An In Vivo Imaging Study in the Rat.
J Nucl Med. 51(11), 1788 - 1795.

Source: 

http://www.eurekalert.org/pub_releases/2010-11/uom-spt110210.php http://www.eurekalert.org/pub_releases/2010-11/sonm-wha102810.php

Topics: 

tags problems: 

Women's brains grow after giving birth

November, 2010

A small study indicates that nurturing mothers and increased reward centers in the brain go hand-in-hand — although the jury’s still out on which comes first.

The issue of “mommy brain” is a complex one. Inconsistent research results make it clear that there is no simple answer to the question of whether or not pregnancy and infant care change women’s brains. But a new study adds to the picture.

Brain scans of 19 women two to four weeks and three to four months after they gave birth showed that grey matter volume increased by a small but significant amount in the midbrain (amygdala, substantia nigra, hypothalamus), prefrontal cortex, and parietal lobe. These areas are involved in motivation and reward, emotion regulation, planning, and sensory perception.

Mothers who were most enthusiastic about their babies were significantly more likely to show this increase in the midbrain regions. The authors speculated that the “maternal instinct” might be less of an instinctive response and more of a result of active brain building. Interestingly, while the brain’s reward regions don’t usually change as a result of learning, one experience that does have this effect is that of addiction.

While the reasons may have to do with genes, personality traits, infant behavior, or present circumstances, previous research has found that mothers who had more nurturing in their childhood had more grey matter in those brain regions involved in empathy and reading faces, which also correlated with the degree of activation in those regions when their baby cried.

A larger study is of course needed to confirm these findings.

Reference: 

[1958] Kim, P., Leckman J. F., Mayes L. C., Feldman R., Wang X., & Swain J. E.
(2010).  The plasticity of human maternal brain: Longitudinal changes in brain anatomy during the early postpartum period..
Behavioral Neuroscience. 124(5), 695 - 700.

Source: 

http://www.telegraph.co.uk/health/healthnews/8076680/Womens-brains-grow-... http://healthland.time.com/2010/10/21/the-mommy-brain-is-bigger-how-love...

Topics: 

tags: 

tags development: 

tags memworks: 

Damage to amygdala can be compensated by another region

September, 2010

A memory function thought to require a specific brain region called the amygdala has now been found to be able to be performed by another region, if the amygdala is impaired.

A number of studies in recent years have revealed the amazing ability of the human brain to compensate for damage down to its part. In the latest of these, it’s been found that loss of the amygdala doesn’t have to mean that new memories will be void of emotion. Instead, it appears, a region called the bed nuclei can step in to take its place. The bed nuclei are slower to process information than the amygdala, and in normal circumstances are inhibited by the amygdala. The study looked specifically at fear conditioning, for which the amygdala has been considered crucial.

The finding offers the hope that therapies to promote compensatory shifts in function might help those who have suffered damage to parts of their brain.

Reference: 

[1792] Poulos, A. M., Ponnusamy R., Dong H-W., & Fanselow M. S.
(2010).  Compensation in the neural circuitry of fear conditioning awakens learning circuits in the bed nuclei of the stria terminalis.
Proceedings of the National Academy of Sciences. 107(33), 14881 - 14886.

Source: 

http://www.eurekalert.org/pub_releases/2010-08/uoc--wmr080210.php

Topics: 

tags: 

tags memworks: 

tags problems: 

Ritalin boosts learning by increasing brain plasticity

March, 2010

A rat study shows how Ritalin improves concentration and, it now appears, speed of learning. The finding may help the development of better-targeted drugs.

A rat study shows how Ritalin improves concentration and, it now appears, speed of learning. The study reveals that it does this by increasing the activity of dopamine at two specific types of neurotransmitter receptors in the amygdala. The dopamine receptor tagged “D2” appears to control the ability to stay focused on a task, while the D1 receptor underlies learning efficiency. The finding may help the development of better-targeted drugs.

Reference: 

[300] Tye, K. M., Tye L. D., Cone J. J., Hekkelman E. F., Janak P. H., & Bonci A.
(2010).  Methylphenidate facilitates learning-induced amygdala plasticity.
Nat Neurosci. 13(4), 475 - 481.

Source: 

http://www.eurekalert.org/pub_releases/2010-03/uoc--rbl030510.php

Topics: 

tags: 

tags lifestyle: 

tags problems: 

tags strategies: 

Why older adults remember the good times better

March, 2010

An imaging study has found differences in brain activity that explain why older adults are better at remembering positive events.

An imaging study reveals why older adults are better at remembering positive events. The study, involving young adults (ages 19-31) and older adults (ages 61-80) being shown a series of photographs with positive and negative themes, found that while there was no difference in brain activity patterns between the age groups for the negative photos, there were age differences for the positive photos. In older adult brains, but not the younger, two emotion-processing regions (the ventromedial prefrontal cortex and the amygdala) strongly influenced the memory-encoding hippocampus.

Reference: 

[312] Addis, D R., Leclerc C. M., Muscatell K. A., & Kensinger E. A.
(2010).  There are age-related changes in neural connectivity during the encoding of positive, but not negative, information.
Cortex. 46(4), 425 - 433.

Source: 

www.physorg.com/news188645719.html http://www.eurekalert.org/pub_releases/2010-03/e-oar032410.php

Topics: 

tags development: 

tags memworks: 

tags problems: 

Pages

Subscribe to RSS - amygdala