User:157.139.21.8/sandbox

Dominance Hierarchy

Hierarchal behavior in animals has been found to overlap in a number of brain areas. One of the areas that has been linked with this behavior is the prefrontal cortex, a region involved with decision making and social behavior. High social rank in a hierarchical group of mice has been associated with increased excitatory synaptic strength and activity in the medial prefrontal cortex of pyramidal neurons, the primary excitatory cell type of the brain. In primates, high ranking macaques have a larger rostral prefrontal cortex in large social groups. In humans, neuroimaging studies with computer stimulated hierarchal conditions, led to increased activity in the ventral and dorsolateral prefrontal cortex, one processing judgment cues and the other processing status of an individual. Lesions studies in various mammal species, including humans, have also led to deficits in processing social hierarchy cues suggesting this area is important in regulating this information. Although the prefrontal cortex has been implicated, there are other downstream targets of the prefrontal cortex that have also been linked in maintaining this behavior. This includes the amygdala through lesion studies in rats and primates which led to disruption in hierarchy, and can effect the individual negatively or positively depending on the subnuclei that is targeted. Additionally, the dorsal medial PFC-medial dorsal thalamus connection has been linked with maintenance of rank in mice. Another area that has been associated is the dorsal raphe nucleus, the primary serotonergic nuclei. In manipulations studies of this region, there were changes in fighting and affiliative behavior in primates and crustations.

Cognitive Genomics