Lateralization in function of insular cortex

Background and Aim: The human insular cortex is a part of the neocortex located in depth of lateral sulcus. Cytoarchitecturally, insula is divided into an anterior (agranular portion), middle (dysgranular portion) and posterior granular regions. Insular cortex is related to temporal, parietal, frontal lobes, brain stem, basal ganglia, thalamus, amygdala and cingulated gyrus. Insula has been involved in processing of taste, auditory, pain, cognitive, speech, self awareness and limbic function. Insula dysfunction is related to neurological disease, such as anxiety, Parkinson, addiction, dementia, bipolar disorder and schizophrenia. Methods: Cardiovascular studies have shown that the left insular cortex concerns parasympathetic regulation versus right insular involved in sympathetic tone. Additionally microinjection glutamate to both insula demonstrate that cardiovascular functions is more on left than the right side. Functional lateralization in middle cerebral artery stroke, showed left insular damage causes increase of norepinephrine in serum. Addiction-related studies have shown that cocaine and methamphetamine reduce gray matter in the right and left insula respectively. Researches of auditory fields demonstrated that the right insula is associated with sound detection and auditory sequencing versus left side involved in auditory recognition of words and musical rhythm processing. Lesion studies showed that left anterior insula involved in aphasia. Survey of somatosensory have shown that right insula is related to the conscious perception of the stimulus and emotional feelings. Also, human study has shown the association of the left insula with the cingulate gyrus involved in lumbar pain. Administration of lipopolysaccharides increases pain. Results: This paper reviews asymmetrical function of human insular cortex. Conclusion: There were some functional & structural differences between the two hemispheres.

کلیدواژه ها:

Lateralization ، insular ، cortex ، function