The comparative effects of early‐life undernutrition and subsequent differential environments on the dendritic branching of pyramidal cells in rat visual cortex

Abstract

Male rats were either undernourished or fed normally from birth to day 21, after which time food was made freely available. At 1 month of age littermate pairs from both nutritional groups were housed in either enriched or impoverished conditions for 30 days and then killed for brain measurements. Significant deficits due to undernutrition were observed in the weight and size of the cerebrum, but not in the thickness or area of the visual cortex. Although there were large differences of between 21 and 39% in the number of higher-order basal dendrites of layers II and III pyramidal cells, and of about 19% in the distal ring intersections, none except the fourth-order branches and intersections at 100 micron from the cell body approached statistical significance. Changes in cerebral weight and size also occurred as a result of differential housing, with the enriched rats showing increased values relative to their impoverished littermates. In contrast to the nutritional treatment, differential housing significantly affected cortical thickness and area, as well as basal dendritic branching of the pyramidal cells. Enriched rats had relative increases of 26% in the number of fifth-order branches and 45-80% in the number of distal ring intersections.

Life‐span dendritic and spine changes in areas 10 and 18 of human cortex: A quantitative golgi study

“…In fact, the magnitude of dendritic regression in the present sample is nearly identical to that in a methodologically similar study on Wernicke's area (Jacobs and Scheibel, 1993): about an 11% decrease in both TDL and MSL from the younger to the older groups. These decreases were localized primarily to third-order and higher dendritic segments, thereby providing support for 1) the relative stability of more primary branches (Carughi et al, 1989), 2) the greater epigenetic sensitivity of more distal segments (Jones and Thomas, 1962;Smit et al, 1972;Greenough and Volkmar, 1973;Uylings et al, 1978;Greenough et al, 1979;Davies and Katz, 1983), and 3) the distoproximal theory of dendritic degeneration (Feldman, 1977;Cupp and Uemura, 1980). Although actual age-related increases in dendritic segment length could not be identified in the present investigation, previous research suggests that proliferative changes are likely (Buell andColeman, 1979, 1981;Flood et al, 1985).…”

Life-span dendritic and spine changes in areas 10 and 18 of human cortex: A quantitative golgi study

“…In fact, the magnitude of dendritic regression in the present sample is nearly identical to that in a methodologically similar study on Wernicke's area (Jacobs and Scheibel, 1993): about an 11% decrease in both TDL and MSL from the younger to the older groups. These decreases were localized primarily to third-order and higher dendritic segments, thereby providing support for 1) the relative stability of more primary branches (Carughi et al, 1989), 2) the greater epigenetic sensitivity of more distal segments (Jones and Thomas, 1962;Smit et al, 1972;Greenough and Volkmar, 1973;Uylings et al, 1978;Greenough et al, 1979;Davies and Katz, 1983), and 3) the distoproximal theory of dendritic degeneration (Feldman, 1977;Cupp and Uemura, 1980).…”

Effects of environmental enrichment on sensitivity to cocaine in female rats: importance of control rates of behavior

“…environments in which animals are housed socially in groups and provided with novel objects to explore and manipulate) during critical periods in development produces a number of neuroanatomical effects that are associated with functional changes in behavior. For instance, rats reared under conditions of environmental enrichment have greater cortical mass (Rosenzweig et al , 1962; Bennett et al , 1969), have greater dendritic branching (Davies and Katz, 1983; Johansson and Belichenko, 2002), and perform better on learning and memory tasks (Kobayashi et al , 2002; Dhanushkodi et al , 2007) than rats reared in isolation. There is also a growing body of evidence that environmental enrichment influences an organism's sensitivity to centrally acting drugs.…”