Neuroscience 2005 Abstract
| Presentation Number: | 309.6 |
|---|---|
| Abstract Title: | Effects of ibotenate lesions of the basal forebrain on recovery sleep after sleep deprivation in rats. |
| Authors: |
Kaur, S.*1
; Burns, J.1
; Junek, A.1
; Semba, K.1
1Dept Anat & Neurobiol, Dalhousie Univ., Halifax, Canada |
| Primary Theme and Topics |
Homeostatic and Neuroendocrine Systems - Biological Rhythms and Sleep -- Sleep |
| Session: |
309. Sleep Behavior Poster |
| Presentation Time: | Sunday, November 13, 2005 2:00 PM-3:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # NN13 |
| Keywords: | Sleep-homeostasis, Lesions, Delta power, Cholinergic |
We previously showed that unilateral ibotenate lesions of the basal forebrain (BF) in rats increased NREM sleep and EEG delta power in all states in both light and dark phases of L:D 12:12 cycle, suggesting that the BF plays an important role in the maintenance of behavioural and cortical arousal [Kaur et al. (2004) SFN Abstr. 196.12]. The BF has also been implicated in adenosinergic regulation of sleep homeostasis. Therefore, in the present study we investigated whether BF ibotenate lesions affect recovery sleep and EEG after 6-h sleep deprivation (SD).
Male rats were implanted with polygraphic electrodes and unilateral/bilateral guide cannulae above the nucleus basalis magnocellularis and substantia innominata. After acclimatization, a 24-h pre-injection recording was conducted followed by injection of 8µg/0.5µl ibotenate or ACSF. On 27th post-injection day animals were recorded for 30-h pre-SD baseline and then sleep deprived by gentle handling for 6 h in the second half of the light phase, followed by a 36-h post-SD recording. The brains were processed for Nissl, AChE staining and immunohistochemistry for cholinergic and peptide markers to assess specific neuronal loss in the BF and cortical cholinergic fiber loss.
As reported earlier, baseline delta power and NREM sleep generally increased after BF ibotenate lesions. In response to SD, lesioned animals showed smaller increases in NREM delta than controls when compared to either pre-injection (ibotenate/ACSF) or pre-SD baseline during the same period of the LD cycle. The amount of increase in NREM sleep after SD did not consistently differ between the groups, although the total post-SD NREM sleep tended to be greater in lesioned animals. These results indicate that BF ibotenate lesions impair the homeostatic ability to increase EEG delta power in response to SD, while enhancing sleep and delta power under baseline conditions. Histological analysis is in progress to examine possible correlations of these sleep and EEG effects with specific cell losses.
Male rats were implanted with polygraphic electrodes and unilateral/bilateral guide cannulae above the nucleus basalis magnocellularis and substantia innominata. After acclimatization, a 24-h pre-injection recording was conducted followed by injection of 8µg/0.5µl ibotenate or ACSF. On 27th post-injection day animals were recorded for 30-h pre-SD baseline and then sleep deprived by gentle handling for 6 h in the second half of the light phase, followed by a 36-h post-SD recording. The brains were processed for Nissl, AChE staining and immunohistochemistry for cholinergic and peptide markers to assess specific neuronal loss in the BF and cortical cholinergic fiber loss.
As reported earlier, baseline delta power and NREM sleep generally increased after BF ibotenate lesions. In response to SD, lesioned animals showed smaller increases in NREM delta than controls when compared to either pre-injection (ibotenate/ACSF) or pre-SD baseline during the same period of the LD cycle. The amount of increase in NREM sleep after SD did not consistently differ between the groups, although the total post-SD NREM sleep tended to be greater in lesioned animals. These results indicate that BF ibotenate lesions impair the homeostatic ability to increase EEG delta power in response to SD, while enhancing sleep and delta power under baseline conditions. Histological analysis is in progress to examine possible correlations of these sleep and EEG effects with specific cell losses.
Supported by CIHR
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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