Effects of dark rearing on dendritic spines in layer IV of the mouse visual cortex. A quantitative electron microscopical study
Freire, M.
Journal of Anatomy 126(Pt 1): 193-201
1978
ISSN/ISBN: 0021-8782 PMID: 649498 Document Number: 132816
The effect of visual deprivation on dendritic spines in the visual cortex layer IV of 19 day old mice was studied by EM. From the serial ultrathin sections of selected dendrites bearing spines, the volume and surface area of dendritic spines and the surface area of their synaptic zones were calculated by planimetric and curvimetric measurements. Employing statistical methods, it was demonstrated that visual deprivation produced a retarded development of some dendritic spines in dark reared mice. This retarded development of some dendritic spines in dark raised mice might produce a real diminution in the number of spines per dendritic segment at a given age because of their asynchronous growth. The fact that the smallest dendritic spines cannot be seen with the light microscope while the number of such small spines is larger in the dark reared mice can explain the apparent reduction in the number of dendritic spines in deprived animals studied in Golgi impregnated material.