Amygdala

Buried deep in the temporal lobes, amygdalas are neuronal computers involved in evaluating and generating emotional behavior.  There are 23 nuclei in each amygdala. The expectation of reward or punishment is a strong determinant of human behavior. The amygdala is involved in assessing reward potential.  The lateral nucleus of the amygdala is the sensory receptive area and the central nucleus provides the interface with motor systems that express conditioned responses.

In animal experiments, the amygdala is known to mediate the conditioned aspects of reward-related stimuli. Heroin is a strong stimulus, for example, whose condition effect is reduced by inactivating the basolateral nucleus. The lateral nucleus of the amygdala responds to amphetamines. The central nucleus of the amygdala receives dense reciprocal dopaminergic afferents from the ventral tegmental area.  

Rats with lesions of the central nucleus exhibit less suppression of behavior elicited by fear, but were able to avoid further presentations of this aversive stimulus. Animals with lesions of the basolateral amygdala were unable to avoid the conditioned aversive stimulus by behavior, but exhibited normal conditioned suppression to this stimulus.

People with bilateral amygdala damage lose some or all of their avoidance behavior and approach strangers with ease; they fail to recognize untrustworthy individuals.  In animal experiments, the amygdala is known to mediate the conditioned aspects of reward-related stimuli. Adolphs et al suggested that the amygdala recognizes and recalls fearful facial expressions. 

Bilateral amygdala damage impairs the recognition of fear in facial expressions. LeDouxs et al   suggested that projections from the posterior thalamus to the amygdala are involved in processing the emotional significance of sounds.  Ueda et al monitored fifteen healthy subjects by fMRI and reported that the amygdala and anterior cingulate cortex play an important role in the expectancy of unpleasant stimuli. Expectation of pleasant stimuli produced activation in the left dorsolateral and left medial prefrontal cortex as well as in the right cerebellum.  

Neuroscience Notes places the human brain at the center of the universe. Since the brain is the organ of the mind, consciousness and all knowledge is contained within the brain. Neuroscience Notes is part of the Persona Digital Psychology and Philosophy Series of related books. The closely related volumes are the Human Brain, Language and Thinking, Emotions and Feelings, and Intelligence and Learning.

  Persona Digital Books

We offer two sources of our books:  Persona Digital Online offers downloads of eBooks, music and other digital documents available to customers all over the world. Click the Download Now buttons on the right to order PDF eBooks  from this website.  Alpha Online ships printed books and nutrient formulas to the US and Canada. Click the Add to Cart button on the left to order printed books for mail deliver to US and Canada. You will go to Alpha Online to complete your printed book order.

Print Books	More Information	Download
	Group Dynamics
	The Good Person
	Pieces of the Puzzle
	The Sound of Music
	Language and Thinking
	I and Thou
	Emotions and Feelings
	Neuroscience Notes
	Children and Family
	Intelligence and Learning
	Religion for 21st Century

Neuroscience Notes is published by Persona Digital Books. Copyright 2011, 2012. All rights to reproduction by any means are reserved. We encourage readers to quote and paraphrase topics from Neuroscience Notes published online and expect proper citations to accompany all derivative writings.  The author is Stephen Gislason MD. The latest date of publication is 2012.  The URL to the book description is http://www.personadigital.net/Persona/Neuroscience/  Persona Digital Online is a download server for digital media.  Also See Persona Digital Music Studio