Browsing by Author "Bennett, C."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Spatial learning and memory deficits after whole-brain irradiation are associated with changes in nmda receptor subunits in the hippocampus
    (Radiation Research Society., 2006) Shi, L.; Adams, Michelle M.; Long, A.; Carter, C.; Bennett, C.; Sonntag, W.; Nicolle, M.; Robbins, M.; D'Agostino, R.; Brunso-Bechtold, J.
    Whole-brain irradiation is used for the treatment of brain tumors, but can it also induce neural changes, with progressive dementia occurring in 20–50% of long-term survivors. The present study investigated whether 45 Gy of whole-brain irradiation delivered to 12-month-old Fischer 344 × Brown Norway rats as nine fractions over 4.5 weeks leads to impaired Morris water maze (MWM) performance 12 months later. Compared to sham-irradiated rats, the irradiated rats demonstrated impaired MWM performance. The relative levels of the NR1 and NR2A but not the NR2B subunits of the NMDA receptor were significantly higher in hippocampal CA1 of irradiated rats compared to control rats. No significant differences were detected for these NMDA subunits in CA3 or dentate gyrus. Further analysis of CA1 revealed that the relative levels of the GluR1 and GluR2 subunits of the AMPA receptor and synaptophysin were not altered by whole-brain irradiation. In summary, a clinically relevant regimen of fractionated whole-brain irradiation led to significant impairments in spatial learning and reference memory and alterations in the relative levels of subunits of the NMDA, but not the AMPA, receptors in hippocampal CA1. These findings suggest for the first time that radiation-induced cognitive impairments may be associated with alterations in glutamate receptor composition.
  • Thumbnail Image
    ItemOpen Access
    The static and dynamic screening of power loss of a two-dimensional electron gas
    (Academic Press, 1998) Bennett, C.; Balkan, N.; Tanatar, Bilal; Celik, H.; Cankurtaran, M.
    Experimental results concerning the well-width dependence of the acoustic-phonon-assisted energy relaxation of a two-dimensional electron gas in GaAs/Ga1-xAlxAs quantum-well structures are compared with theoretical models that involve piezoelectric and deformation-potential scattering and the effects of static and dynamic screening of the electron-acoustic phonon interaction. It is shown that screening only slightly modifies the predictions of the approximate calculations. © 1998 Academic Press.