Contents
List of Figures
Figure 2.1 “Act F.A.S.T.” Stroke publicity campaign poster, as displayed on the UK National Health Service website: http://www.nhs.uk/. Copyright NHS England. Used under terms of Open Government Licence. http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.
Figure 2.2 Ischemic stroke. A major artery supplying the brain becomes blocked, typically by a blood clot, depriving part of the brain of its blood supply.
Figure 2.3 Simplified circuit diagram for the cerebral cortex, showing pyramidal neurons, the output neurons of the cortex, and nonpyramidal neurons, the intrinsic inhibitory neurons of the cortex.
Figure 2.4 Outcome following a stroke. Brain cells in area A of the cortex (stroke core area) are completely lost. Some cells in neighboring area B have survived but others have been lost, as have connections to other areas. And brain cells in more distant area C, though not directly affected, have also lost connections and are functionally disturbed.
Figure 3.1 Germinal zones in the developing brain. The inner surface, the ventricular zone, is packed with dividing precursor cells. These generate the young neurons that migrate out to form the cortical plate, the gray matter of the developing cortex.
Figure 3.2 Within the hippocampus, a major structure in the mammalian forebrain connecting with other brain regions, lies the V-shaped dentate gyrus with a densely packed layer of granule neurons. On the inner surface of this layer lies a population of neural stem cells that generate new neurons throughout the life of the mammal; these go on to mature and join the granule cell population.
Figure 4.1 Dopamine and Parkinson’s disease. Dopaminergic neurons of the substantia nigra normally project widely through the striatum and forebrain (right side of figure). In Parkinson’s disease, however, these dopaminergic neurons die, and this projection is lost (left side of figure).
Figure 6.1 Spinal cord injury. As shown here in the neck region, a fracture to the spinal cord compresses the spinal column, and transects nerve fibers running up and down the spinal cord.
Figure 6.2 Structure of retina. In the healthy retina (left panel), close apposition and interaction of the photoreceptors (rods and cones) and the pigment epithelium are critical for the health and survival of the photoreceptors. In macular degeneration (right panel), Bruch’s membrane (on which the pigment cells sit) degenerates, leading to the death of pigment epithelium cells and the degeneration of the photoreceptors.
Figure 12.1 Pluripotency and reprogramming. During normal embryogenesis, the fertilized egg gives rise to a ball of cells called the “blastula,” within which is a cluster of pluripotent stem cells called the “inner cell mass.” These pluripotent cells generate all the cell types that make up the body. Reprogramming is the process whereby differentiated cells, such as skin fibroblasts, can be turned back into pluripotent cells. Direct reprogramming turns cells of one differentiated type (such as fibroblasts) directly into another (for example, neurons).
List of Boxs
Box 1 Types of Nerve Cells
Box 2 Types of Stem Cells