The precuneus is a structure in the brain positioned above the cuneus and located in the parietal lobe. According to Jaydeep, the precuneus is part of the limbic system. Comparative brain sizes In the anatomy of animals, the brain, or encephalon (Greek for in the head), is the higher, supervisory center of the nervous system. ... Cuneus (Latin for wedge; plural, cunei), the architectural term applied to the wedge-shaped divisions of the Roman theatre separated by the scalae or stairways; see Vitruvius v. ... The parietal lobe is a lobe in the brain. ... The limbic system is a group of brain structures that are involved in various emotions such as aggression, fear, pleasure and also in the formation of memory. ...
Furthermore, precuneus and surrounding posteromedial areas are amongst the brain structures displaying the highest resting metabolic rates (hot spots) and are characterized by transient decreases in the tonic activity during engagement in non-self-referential goal-directed actions (default mode of brain function).
The precuneus seemed poised to break out into the mainstream in the mid-90's, ever since it was found to be highly active when people were remembering words from a list they had studied earlier (compared to new words they hadn't studied).
The precuneus shows shows the highest resting metabolic rate of all the regions implicated in "the resting state" (often assessed with eyes closed, when the subjects presumably have a major alpha rhythm going in their EEGs, but also evaluated during "passive viewing" conditions when people are looking at a + sign or some other image).
Activation tightly correlated with numerical distance was observed mainly in a group of parietal areas distributed bilaterally along the intraparietal sulci and in the precuneus, as well as in the left middle temporal gyrus and posterior cingulate
In contrast, regional CV was significantly lower in AD in temporal and parietal cortices, which were the regions that along with the precuneus had the largest metabolic decrements, though the precuneus had increased CV Nora D. Volkow; Wei Zhu; Christoph A. Felder; Klaus Mueller; Tomihisa F. Welsh; Gene J. Wang; Mony J. de Leon.
The enhanced CV in precuneus, despite its marked reductions in metabolism, suggests that increases in regional homogeneity in parietal and temporal cortices are not a mere reflection of the decrement in metabolism
Feeds |
Contact