The orbitofrontal cortex （OFC） is particularly important for the neural representation of reward value. Previous studies indicated that electroencephalogram （EEG） activity in the OFC was involved in drug administr...The orbitofrontal cortex （OFC） is particularly important for the neural representation of reward value. Previous studies indicated that electroencephalogram （EEG） activity in the OFC was involved in drug administration and withdrawal. The present study investigated EEG activity in the OFC in rats during the development of food reward and craving. Two environments were used separately for control and food-related EEG recordings. In the food-related environment rats were first trained to eat chocolate peanuts; then they either had no access to this food, but could see and smell it （craving trials）, or had free access to this food （reward trials）. The EEG in the left OFC was recorded during these trials. We showed that, in the food-related environment the EEG activity peaking in the delta band （2-4 Hz） was significantly correlated with the stimulus, increasing during food reward and decreasing during food craving when compared with that in the control environment. Our data suggests that EEG activity in the OFC can be altered by food reward; moreover, delta rhythm in this region could be used as an index monitoring changed signal underlying this reward.展开更多
The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiologi...The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiological factors are promising since are more directly related to neuroplasticity,which supports recovery in stroke patients,than neurovascular factors.In this retrospective observational study,we investigated brain neuronal activity assessed via spectral features and Higuchi's fractal dimension(HFD) of electroencephalographic signals in acute phase(2–10 days from symptom onset,T0) and sub-acute phase(2.5 months,T1) in 24 patients affected by unilateral middle cerebral artery stroke.Longitudinal assessment of the clinical deficits was performed using the National Institutes of Health Stroke Scale(NIHSS),together with the effective recovery calculated as the ratio between difference of NIHSS at T0 and T1 over the NIHSS value at T0.We observed that delta and alpha band electroencephalographic signal power changed between the two phases in both the hemispheres ipsilateral(ILH) and contralateral(CHL) to the lesion.Moreover,at T0,bilateral higher delta band power correlated with worse clinical conditions(Spearman's rs = 0.460,P = 0.027 for ILH and rs = 0.508,P = 0.013 for CLH),whereas at T1 this occurred only for delta power in ILH(rs = 0.411,P = 0.046) and not for CHL.Inter-hemispheric difference(ILH vs.CLH) of alpha power in patients was lower at T0 than at T1(P = 0.020).HFD at T0 was lower than at T1(P = 0.005),and at both phases,ILH HFD was lower than CLH HFD(P = 0.020).These data suggest that inter-hemispheric low band asymmetry and fractal dimension changes from the acute to the sub-acute phase are sensitive to neuroplasticity processes which subtend clinical recovery.The study protocol was approved by the Bioethical Committee of Ospedale San Giovanni Calibita Fatebenefretelli(No.40/2011) on July 14,2011.展开更多
基金National Science Foundation of China (3047055330530270+10 种基金30670669 30770700)973 Program (2005CB522803 2007CB947703)863 Program (O7013810 2006AA02A116)The Major State Basic Research of China (2003CB716600)Chinese-Finnish International Collaboration Project-neuro (30621130076)Program of CASC (KSCX1-YW-R-33YZ200737)National Key Technologies R & D Program and Yunnan Science and Technique Program (2006PT08-2)
文摘The orbitofrontal cortex （OFC） is particularly important for the neural representation of reward value. Previous studies indicated that electroencephalogram （EEG） activity in the OFC was involved in drug administration and withdrawal. The present study investigated EEG activity in the OFC in rats during the development of food reward and craving. Two environments were used separately for control and food-related EEG recordings. In the food-related environment rats were first trained to eat chocolate peanuts; then they either had no access to this food, but could see and smell it （craving trials）, or had free access to this food （reward trials）. The EEG in the left OFC was recorded during these trials. We showed that, in the food-related environment the EEG activity peaking in the delta band （2-4 Hz） was significantly correlated with the stimulus, increasing during food reward and decreasing during food craving when compared with that in the control environment. Our data suggests that EEG activity in the OFC can be altered by food reward; moreover, delta rhythm in this region could be used as an index monitoring changed signal underlying this reward.
基金FZ and FT obtained financial support from the Italian Ministry of Health Cod.GR-2008-1138642 "Promoting recovery from Stroke:individually enriched therapeutic intervention in Acute phase"PNR-CNR Aging Program
文摘The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiological factors are promising since are more directly related to neuroplasticity,which supports recovery in stroke patients,than neurovascular factors.In this retrospective observational study,we investigated brain neuronal activity assessed via spectral features and Higuchi's fractal dimension(HFD) of electroencephalographic signals in acute phase(2–10 days from symptom onset,T0) and sub-acute phase(2.5 months,T1) in 24 patients affected by unilateral middle cerebral artery stroke.Longitudinal assessment of the clinical deficits was performed using the National Institutes of Health Stroke Scale(NIHSS),together with the effective recovery calculated as the ratio between difference of NIHSS at T0 and T1 over the NIHSS value at T0.We observed that delta and alpha band electroencephalographic signal power changed between the two phases in both the hemispheres ipsilateral(ILH) and contralateral(CHL) to the lesion.Moreover,at T0,bilateral higher delta band power correlated with worse clinical conditions(Spearman's rs = 0.460,P = 0.027 for ILH and rs = 0.508,P = 0.013 for CLH),whereas at T1 this occurred only for delta power in ILH(rs = 0.411,P = 0.046) and not for CHL.Inter-hemispheric difference(ILH vs.CLH) of alpha power in patients was lower at T0 than at T1(P = 0.020).HFD at T0 was lower than at T1(P = 0.005),and at both phases,ILH HFD was lower than CLH HFD(P = 0.020).These data suggest that inter-hemispheric low band asymmetry and fractal dimension changes from the acute to the sub-acute phase are sensitive to neuroplasticity processes which subtend clinical recovery.The study protocol was approved by the Bioethical Committee of Ospedale San Giovanni Calibita Fatebenefretelli(No.40/2011) on July 14,2011.
