Abstract
Aims
The aim was to characterise changes in brain activity and plasticity induced by environmental enrichment and dietary restriction (EEDR), as a model of active lifestyle, and to contrast these to the state of chronic stress induced by daily injections of corticosterone (CORT).
Methods
Male rats underwent EEDR or CORT over 8 and 4 weeks, respectively. All animals were tested for novel object recognition, locomotor behaviour and BRDU was injected to measure neurogenesis. At the end they were implanted with stimulating (CA1) and recording (prefrontal cortex) electrodes and EEG was recorded under urethane anaesthesia. We measured long term potentiation (LTP), after high frequency stimulation. We also performed spectral analysis of the evoked potentials (EPs), and of the resting EEG signal.
Results
EEDR increased novel object exploration, an indication of improved cognition. Locomotor activity was unaffected. Neurogenesis was increased in the dentate gyrus. In EEG, LTP was increased, and there was a significant increase in EPs spectral power in 70-90 Hz frequency.
CORT treatment decreased novel object exploration, as well as time spent in centre of open field arena. Neurogenesis in the dentate gyrus was decreased. LTP was decreased and there was a decrease in the low frequency (0-10Hz) range of EPs spectral power, as well as a reduced delta power in the resting EEG.
Conclusions
The two protocols caused opposite effects on multiple parameters linked to brain plasticity and cognition. Of particular interest are the novel findings of changes in baseline resting EEG and in EPs, in addition to LTP.
The aim was to characterise changes in brain activity and plasticity induced by environmental enrichment and dietary restriction (EEDR), as a model of active lifestyle, and to contrast these to the state of chronic stress induced by daily injections of corticosterone (CORT).
Methods
Male rats underwent EEDR or CORT over 8 and 4 weeks, respectively. All animals were tested for novel object recognition, locomotor behaviour and BRDU was injected to measure neurogenesis. At the end they were implanted with stimulating (CA1) and recording (prefrontal cortex) electrodes and EEG was recorded under urethane anaesthesia. We measured long term potentiation (LTP), after high frequency stimulation. We also performed spectral analysis of the evoked potentials (EPs), and of the resting EEG signal.
Results
EEDR increased novel object exploration, an indication of improved cognition. Locomotor activity was unaffected. Neurogenesis was increased in the dentate gyrus. In EEG, LTP was increased, and there was a significant increase in EPs spectral power in 70-90 Hz frequency.
CORT treatment decreased novel object exploration, as well as time spent in centre of open field arena. Neurogenesis in the dentate gyrus was decreased. LTP was decreased and there was a decrease in the low frequency (0-10Hz) range of EPs spectral power, as well as a reduced delta power in the resting EEG.
Conclusions
The two protocols caused opposite effects on multiple parameters linked to brain plasticity and cognition. Of particular interest are the novel findings of changes in baseline resting EEG and in EPs, in addition to LTP.
| Original language | English |
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| Title of host publication | Forum of Neuroscience 2016 |
| Publisher | Federation of European Neuroscience Societies |
| Publication status | Published - Jul 2016 |
| Event | 10th FENS Forum of Neuroscience, Copenhagen - Copenhagen Duration: 2 Jul 2016 → 6 Jul 2016 |
Conference
| Conference | 10th FENS Forum of Neuroscience, Copenhagen |
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| Period | 2/07/2016 → 6/07/2016 |