BIOLOGY 2D03 Lecture Notes - Lactic Acidosis, Vinblastine, Sildenafil
28 Jan 2013
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Document Summary
Neurocytology i - the structure of the neuron. The variation in the dendritic spine length has lead to two general hypothesis about the function of spines: they serve to isolate the spine electrically from the dendrite. This hypothesis suggests that spines would be capable of acting autonomically from the electrical events that travel up and down a dendritic shaft. Spines with long, thin neck would be particularly well isolated, whereas those with short, wide necks would act more like the shaft: spines provide for an isolated chemical environment in the spine head. This hypothesis is particularly relevant to the buildup of ca+2 within the cytoplasm, an event associated with long-term changes in the excitability of a neuron"s membrane. Again, spines with long necks would be able to regulate ca+2 conc locally where as those with short necks would follow a regulatory plan established for the dendrite as a whole. The axon hillock is devoid of ribosomes and rer.
