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In biological terms, human development entails growth from a one-celled zygote to an adult human being. Fertilization occurs when the sperm cell successfully enters and fuses with an egg cell . [2] The genetic material of the sperm and egg then combine to form a single cell called a zygote and the germinal stage of prenatal development commences.
Both structures exhibit localized vesicles at the active sites, clustered receptors at the post-synaptic membrane, and glial cells that encapsulate the entire synaptic cleft. In terms of synaptogenesis, both synapses exhibit differentiation of the pre- and post-synaptic membranes following initial contact between the two cells.
Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. [1] Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater than the overall rate of cellular degradation (the destruction of biomolecules via the proteasome, lysosome or autophagy, or catabolism).
Growth from any such meristem at the tip of a root or shoot is termed primary growth and results in the lengthening of that root or shoot. Secondary growth results in widening of a root or shoot from divisions of cells in a cambium. [38] In addition to growth by cell division, a plant may grow through cell elongation. [39]
Neuronal precursor cells proliferate in the ventricular zone of the developing neocortex, where the principal neural stem cell is the radial glial cell. The first postmitotic cells must leave the stem cell niche and migrate outward to form the preplate, which is destined to become Cajal–Retzius cells and subplate neurons. These cells do so by ...
For example, stem cells requires the sox2 gene to maintain pluripotency and is used to detect enduring concentrations of stem cells in CNS tissue. The protein nestin is an intermediate filament , which is essential for the radial growth of axons , and is therefore used to detect the formation of new synapses .
Through environmental enrichment, researchers were able to enhance and partially repair memory deficits in mice between ages of 2 to 7 months with characteristics of Alzheimer's disease. Mice in enriched environments performed significantly better on object recognition tests and the Morris Water Maze than they had when they were in standard ...
Lashley contributed to psychology and neuropsychology in a number of ways. First, his publication, Brain Mechanisms and Intelligence: A Quantitative Study of Injuries to the Brain (1929) found evidence to suggest the idea of localization was wrong and brought to life the idea that the brain and its multiple parts work together for memory and ...