Supramarginal gyrus lies at end of sylvian fissure ○Īngular gyrus lies ventral to supramarginal gyrus ○ Superior & inferior parietal lobules lie posterior to postcentral gyrus ○ Postcentral gyrus: Primary somatosensory cortex –Ĭontains topographical map of contralateral body –įace, tongue, lips are inferior trunk, upper limb superolateral lower limb on medial aspect ○ Separated from occipital lobe by parietooccipital sulcus (medial surface) ○ Orbital gyri cover base of frontal lobe gyrus rectus medially Inferior sulcus separates middle & inferior gyri ○ Superior sulcus separates superior & middle gyri – Premotor cortex: Within gyrus just anterior to precentral gyrus (motor cortex) ○ģ additional major gyri: Superior frontal gyrus, middle frontal gyrus, & inferior frontal gyrus – Head/face lateral, legs/feet along medial surface ○ Precentral gyrus contains primary motor cortex –ĭetailed topographically-organized map ("motor homunculus") of contralateral body – Ĭentral sulcus separates frontal, parietal lobes ○.Sulci separate gyri, fissures separate hemispheres/lobes Sulci (fissure): CSF-filled grooves or clefts that separate gyri echogenic on US ○ Gyri : Complex convolutions of brain cortex hypoechoic on ultrasound (US) Since the ordered and layered cortical structure is important for its function, nanofibrous scaffolds should be carefully designed for controlling cell organization and integration following transplantation into the lesion site, which is critical to the success of stem cell-based therapy after a brain injury or stroke. 66 However, few premature neurons survived at the lesion site 6 weeks posttransplantation and these cells also exhibited a disorganized structure with limited integration with host cortical tissue. 65 The hydrogel further enhanced the survival of encapsulated NSCs and reduced the formation of reactive glial cells. The hydrogel not only created a permissive environment for axons to regenerate at the lesion site but also connected the brain tissue together. The RADA16-IKVAV peptide solution, when injected into the injured brain lesion site, rapidly assembled into nanofibrous hydrogel in situ that filled the lesion cavity. Another study has looked at implanting, self-assembled hydrogels with nanofibrous structure to deliver exogenous NSCs for brain tissue regeneration after injuries. 55 However, this nanofibrous scaffold failed to fill the lesion cavity cohesively. Aligned, electrospun PLA nanofibers have induced robust and functional vascularization in the fiber orientation, neurogenesis, and integration of the newly generated neurons into a normal brain circuitry ( Fig. 26.4). Radially aligned nanofibers, mimicking some of the physical characteristics of brain cortex, have been implanted into the injured lesion cavity to promote host brain tissue regrowth and regeneration after injury. Furthermore, the ongoing inflammation at the lesion site and the lack of supportive tissue structure and vasculature within the cavity present a hostile environment that result in low cell survival, as well as poor control over differentiation and engraftment of transplanted stem cells. Stroke and traumatic injury often lead to the loss of nerve tissue and the formation of a lesion cavity that is primarily located to the cortex. Brain cortex has a very organized layered structure.