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Selective rapid eye movement sleep deprivation affects cell size and number in kitten locus coeruleus.

Shaffery JP, Allard JS, Manaye KF, Roffwarg HP - Front Neurol (2012)

Bottom Line: The estimated total number of TH-ir cells in LC was significantly lower in the RD than in the TXC kittens and numerically lower than in the HCC animals.HCC cells were significantly larger than TH-ir cells in the RD kittens.These data are consistent with presumed reduction in NE in forebrain areas, including visual cortex, caused by 1 week of REMSD.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry and Human Behavior, University of Mississippi Medical Center Jackson, MS, USA.

ABSTRACT
Cells in the locus coeruleus (LC) constitute the sole source of norepinephrine (NE) in the brain and change their discharge rates according to vigilance state. In addition to its well established role in vigilance, NE affects synaptic plasticity in the postnatal critical period (CP) of development. One form of CP synaptic plasticity affected by NE results from monocular occlusion, which leads to physiological and cytoarchitectural alterations in central visual areas. Selective suppression of rapid eye movement sleep (REMS) in the CP kitten enhances the central effects of monocular occlusion. The mechanisms responsible for heightened cortical plasticity following REMS deprivation (REMSD) remain undetermined. One possible mediator of an increase in plasticity is continuous NE outflow, which presumably persists during extended periods of REMSD. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of NE and serves as a marker for NE-producing cells. We selectively suppressed REMS in kittens for 1 week during the CP. The number and size of LC cells expressing immunoreactivity to tyrosine hydroxylase (TH-ir) was assessed in age-matched REMS-deprived (RD)-, treatment-control (TXC)-, and home cage-reared (HCC) animals. Sleep amounts and slow wave activity (SWA) were also examined relative to baseline. Time spent in REMS during the study was lower in RD compared to TXC animals, and RD kittens increased SWA delta power in the latter half of the REMSD period. The estimated total number of TH-ir cells in LC was significantly lower in the RD than in the TXC kittens and numerically lower than in the HCC animals. The size of LC cells expressing TH-ir was greatest in the HCC group. HCC cells were significantly larger than TH-ir cells in the RD kittens. These data are consistent with presumed reduction in NE in forebrain areas, including visual cortex, caused by 1 week of REMSD.

No MeSH data available.


Related in: MedlinePlus

Changes in ECoG delta power by group. Average delta power during 30 artifact-free, 4 s periods of SWS is plotted for each group on the baseline day and shaker days 3 and 6. The DAY by GROUP interaction is significant (F = 7.13, df = 2.10, p = 0.012). The RD group (green bars) successively increases delta power whereas the TXC group (yellow bars) first shows slightly decreased delta power that later levels off. Post hoc comparisons between the two groups do not reach statistical significance on any single day, but trended toward differences between each other on DAY 3 and DAY6 (p = 0.051, p = 0.056, respectively; Bonferroni corrected post hoct-tests). The rising delta power in the RD group’s SWS achieved significance in its difference from baseline on DAY6 (*p = 0.047).
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Figure 2: Changes in ECoG delta power by group. Average delta power during 30 artifact-free, 4 s periods of SWS is plotted for each group on the baseline day and shaker days 3 and 6. The DAY by GROUP interaction is significant (F = 7.13, df = 2.10, p = 0.012). The RD group (green bars) successively increases delta power whereas the TXC group (yellow bars) first shows slightly decreased delta power that later levels off. Post hoc comparisons between the two groups do not reach statistical significance on any single day, but trended toward differences between each other on DAY 3 and DAY6 (p = 0.051, p = 0.056, respectively; Bonferroni corrected post hoct-tests). The rising delta power in the RD group’s SWS achieved significance in its difference from baseline on DAY6 (*p = 0.047).

Mentions: Rapid eye movement sleep deprivation affected SWA (delta frequency band, 0.7–4.4 Hz) power during SWS. No difference in delta power was present in the baseline recordings of the two shaker groups (RD and TXC). Tests for specific contrasts determined that by the end of the study both groups displayed cumulative changes in SWA (Figure 2) but in opposite directions (F = 10.58, df = 1.5, p = 0.028). SWA trended higher in the RD group on the third day of REMSD and elevated significantly by the sixth day relative to baseline (F = 7.13, df = 2.10, p = 0.012). Shaker-control animals showed only a slight reduction in SWA that did not achieve statistical significance at any point in the cage-shaking period (Figure 2). Differences between the two groups serially increased on the third and sixth days, but the disparities did not reach significance on either day (p = 0.051; p = 0.058, respectively; Bonferroni corrected, post hoct-tests).


Selective rapid eye movement sleep deprivation affects cell size and number in kitten locus coeruleus.

Shaffery JP, Allard JS, Manaye KF, Roffwarg HP - Front Neurol (2012)

Changes in ECoG delta power by group. Average delta power during 30 artifact-free, 4 s periods of SWS is plotted for each group on the baseline day and shaker days 3 and 6. The DAY by GROUP interaction is significant (F = 7.13, df = 2.10, p = 0.012). The RD group (green bars) successively increases delta power whereas the TXC group (yellow bars) first shows slightly decreased delta power that later levels off. Post hoc comparisons between the two groups do not reach statistical significance on any single day, but trended toward differences between each other on DAY 3 and DAY6 (p = 0.051, p = 0.056, respectively; Bonferroni corrected post hoct-tests). The rising delta power in the RD group’s SWS achieved significance in its difference from baseline on DAY6 (*p = 0.047).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3351802&req=5

Figure 2: Changes in ECoG delta power by group. Average delta power during 30 artifact-free, 4 s periods of SWS is plotted for each group on the baseline day and shaker days 3 and 6. The DAY by GROUP interaction is significant (F = 7.13, df = 2.10, p = 0.012). The RD group (green bars) successively increases delta power whereas the TXC group (yellow bars) first shows slightly decreased delta power that later levels off. Post hoc comparisons between the two groups do not reach statistical significance on any single day, but trended toward differences between each other on DAY 3 and DAY6 (p = 0.051, p = 0.056, respectively; Bonferroni corrected post hoct-tests). The rising delta power in the RD group’s SWS achieved significance in its difference from baseline on DAY6 (*p = 0.047).
Mentions: Rapid eye movement sleep deprivation affected SWA (delta frequency band, 0.7–4.4 Hz) power during SWS. No difference in delta power was present in the baseline recordings of the two shaker groups (RD and TXC). Tests for specific contrasts determined that by the end of the study both groups displayed cumulative changes in SWA (Figure 2) but in opposite directions (F = 10.58, df = 1.5, p = 0.028). SWA trended higher in the RD group on the third day of REMSD and elevated significantly by the sixth day relative to baseline (F = 7.13, df = 2.10, p = 0.012). Shaker-control animals showed only a slight reduction in SWA that did not achieve statistical significance at any point in the cage-shaking period (Figure 2). Differences between the two groups serially increased on the third and sixth days, but the disparities did not reach significance on either day (p = 0.051; p = 0.058, respectively; Bonferroni corrected, post hoct-tests).

Bottom Line: The estimated total number of TH-ir cells in LC was significantly lower in the RD than in the TXC kittens and numerically lower than in the HCC animals.HCC cells were significantly larger than TH-ir cells in the RD kittens.These data are consistent with presumed reduction in NE in forebrain areas, including visual cortex, caused by 1 week of REMSD.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry and Human Behavior, University of Mississippi Medical Center Jackson, MS, USA.

ABSTRACT
Cells in the locus coeruleus (LC) constitute the sole source of norepinephrine (NE) in the brain and change their discharge rates according to vigilance state. In addition to its well established role in vigilance, NE affects synaptic plasticity in the postnatal critical period (CP) of development. One form of CP synaptic plasticity affected by NE results from monocular occlusion, which leads to physiological and cytoarchitectural alterations in central visual areas. Selective suppression of rapid eye movement sleep (REMS) in the CP kitten enhances the central effects of monocular occlusion. The mechanisms responsible for heightened cortical plasticity following REMS deprivation (REMSD) remain undetermined. One possible mediator of an increase in plasticity is continuous NE outflow, which presumably persists during extended periods of REMSD. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of NE and serves as a marker for NE-producing cells. We selectively suppressed REMS in kittens for 1 week during the CP. The number and size of LC cells expressing immunoreactivity to tyrosine hydroxylase (TH-ir) was assessed in age-matched REMS-deprived (RD)-, treatment-control (TXC)-, and home cage-reared (HCC) animals. Sleep amounts and slow wave activity (SWA) were also examined relative to baseline. Time spent in REMS during the study was lower in RD compared to TXC animals, and RD kittens increased SWA delta power in the latter half of the REMSD period. The estimated total number of TH-ir cells in LC was significantly lower in the RD than in the TXC kittens and numerically lower than in the HCC animals. The size of LC cells expressing TH-ir was greatest in the HCC group. HCC cells were significantly larger than TH-ir cells in the RD kittens. These data are consistent with presumed reduction in NE in forebrain areas, including visual cortex, caused by 1 week of REMSD.

No MeSH data available.


Related in: MedlinePlus