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Pullman, WA, United States

Hight K.,Sleep and Performance Research Center | Hallett H.,Sleep and Performance Research Center | Hallett H.,University of Washington | Churchill L.,Sleep and Performance Research Center | And 4 more authors.
Brain Research | Year: 2010

Sensory input to different cortical areas differentially varies across the light-dark cycle and likely is responsible, in part, for activity-dependent changes in time-of-day differences in protein expression such as Fos. In this study we investigate time-of-day differences between dark (just before light onset) and light (just before dark onset) for the number of immunoreactive (IR) neurons that stained for tumor necrosis factor alpha (TNFα), interleukin-1β (IL1β), nerve growth factor (NGF), the neuronal nuclear protein (NeuN) and Fos in the rat somatosensory cortex (Sctx) and visual cortex (Vctx). Additionally, astrocyte IL1β-IR in the Sctx and Vctx was determined. TNFα and IL1β, as well as the immediate early gene protein Fos, were higher at the end of the dark phase (2300 h) compared to values obtained at the end of the light phase (1100 h) in the Sctx and Vctx. IL1β-IR in Sctx and Vctx astrocytes was higher at 2300 h than that observed at 1100 h. . In contrast, the number of NGF-IR neurons was higher in the Vctx than in the Sctx but did not differ in time. However, the density of the NGF-IR neurons in layer V was greater at 2300 h in the Sctx than at 1100 h. NeuN-IR was higher at 2300 h in the Sctx but was lower at this time in the Vctx compared to 1100 h. These data demonstrate that expressions of the molecules examined are dependent on activity, the sleep-wake cycle and brain location. These factors interact to modulate time-of-day expression. © 2010 Elsevier B.V. All rights reserved. Source


Hallett H.,Sleep and Performance Research Center | Hallett H.,University of Washington | Churchill L.,Sleep and Performance Research Center | Taishi P.,Sleep and Performance Research Center | And 3 more authors.
Brain Research | Year: 2010

Activity-dependent changes in cortical protein expression may mediate long-term physiological processes such as sleep and neural connectivity. In this study we determined the number of nerve growth factor (NGF)- and interleukin-1β (IL1β)-immunoreactive (IR) cells in the somatosensory cortex (Sctx) in response to 2 h of mystacial whisker stimulation. Manual whisker stimulation for 2 h increased the number of NGF-IR cells within layers II-V in activated Sctx columns, identified by enhanced Fos-IR. IL1β-IR neurons increased within layers II-III and V-VI in these activated columns and IL1β-IR astrocytes increased in layers I, II-III and V as well as the external capsule beneath the activated columns. These whisker-stimulated increases in the Sctx did not occur in the auditory cortex. These data demonstrate that expression of NGF or IL1β in Sctx neurons and IL1β in Sctx astrocytes is, in part, afferent input-dependent. © 2010 Elsevier B.V. All rights reserved. Source

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