Limbic system concepts

Needless to say, this turns the concept of human brain functioning upside down, and ronoves an important distinction made by some to divide humans from the rest of the animal kingdom. If true, the innate, hard-wired, patterns in the limbic system that make up the basic emotions have much more importance in human brain functioning than was previously thought. It also might lead to vastly improved engineering means to process information with the efficiency of the human brain (Figure 6.22.4). 

FIGURE 6.22.4 In their concept of brain visual function, Kbrner and Matsumoto (2002) attribute a visual representation of objects to various older structures of the brain (colliculus superior (CS) and lateral geniculate nucleus (LGN)). Higher-level processing in the inferotemporal cortex is limited by persona attributes defined by the amygdala (part of the limbic system). (From Kbrner, E. and Matsumoto, G., IEEE Eng. Med. Biol. Mag., 21, 121, September/October 2002. With permission. 2002 IEEE.)... 

The concept of stress sensidzation , whereby early life stressors can induce an enhanced reactivity to later environmental adversities (review ed in Read et al., 2005), may also be relevant to the etiology of schizophrenia. This phenomenon, w hich results in abnormal activation of the HPA axis, is thought to involve alterations in the mesolimbic dopamine system (review ed in Laruelle, 2000) resulting in excessive release of dopamine, a hallmark of psychotic episodes (Laruelle et al., 1996). Taken together, it appears likely that prenatal developmental abnormalities in limbic stmctures that regulate the HPA axis predispose this system to sensitivity to stressors in early childhood and adolescent maturation. This predisposition may then play a key role in the precipitation of psychotic episodes, as well as the deterioration of brain function that accompanies the progression of the disease. 

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