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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

Proportion of time spent in each of three vigilance states is graphed for the four 24 h periods analyzed within the 8-day experimental protocol (baseline day and 7 shaker days). On each graph, the percent times spent in REMS, rapid eye movement sleep; SWS, slow wave sleep, and waking (WAKE) are plotted. RD = green bars; TXC = yellow bars; **significantly different from corresponding TXC mean; p = 0.001 (Bonferroni corrected post hoct-tests).
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Figure 1: Proportion of time spent in each of three vigilance states is graphed for the four 24 h periods analyzed within the 8-day experimental protocol (baseline day and 7 shaker days). On each graph, the percent times spent in REMS, rapid eye movement sleep; SWS, slow wave sleep, and waking (WAKE) are plotted. RD = green bars; TXC = yellow bars; **significantly different from corresponding TXC mean; p = 0.001 (Bonferroni corrected post hoct-tests).

Mentions: During baseline, percent time in all three vigilance states was similar in TXC and RD animals (Figure 1). Repeated-measures ANOVA of group-by-day effects for each of the vigilance states demonstrated a difference in REMS proportions in the two groups, but no significant SWS or WAKE differences were uncovered (REMS, F = 604.8, p = 0.0001; WAKE, F = 2.25, NS; SWS, F = 0.2, NS). The RD group experienced a reduction in REMS to 2% of recording time on the first day and to 11% on the sixth day (Figure 1). REMS was reduced overall by 80% from baseline values in the RD animals. Early in the REMSD period, the amount of lost REMS tended to be replaced by WAKE. Toward the end of REMSD, the trend in the direction of compensatory WAKE time progressively gave way to a non-significant increase in SWS.


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)

Proportion of time spent in each of three vigilance states is graphed for the four 24 h periods analyzed within the 8-day experimental protocol (baseline day and 7 shaker days). On each graph, the percent times spent in REMS, rapid eye movement sleep; SWS, slow wave sleep, and waking (WAKE) are plotted. RD = green bars; TXC = yellow bars; **significantly different from corresponding TXC mean; p = 0.001 (Bonferroni corrected post hoct-tests).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Proportion of time spent in each of three vigilance states is graphed for the four 24 h periods analyzed within the 8-day experimental protocol (baseline day and 7 shaker days). On each graph, the percent times spent in REMS, rapid eye movement sleep; SWS, slow wave sleep, and waking (WAKE) are plotted. RD = green bars; TXC = yellow bars; **significantly different from corresponding TXC mean; p = 0.001 (Bonferroni corrected post hoct-tests).
Mentions: During baseline, percent time in all three vigilance states was similar in TXC and RD animals (Figure 1). Repeated-measures ANOVA of group-by-day effects for each of the vigilance states demonstrated a difference in REMS proportions in the two groups, but no significant SWS or WAKE differences were uncovered (REMS, F = 604.8, p = 0.0001; WAKE, F = 2.25, NS; SWS, F = 0.2, NS). The RD group experienced a reduction in REMS to 2% of recording time on the first day and to 11% on the sixth day (Figure 1). REMS was reduced overall by 80% from baseline values in the RD animals. Early in the REMSD period, the amount of lost REMS tended to be replaced by WAKE. Toward the end of REMSD, the trend in the direction of compensatory WAKE time progressively gave way to a non-significant increase in SWS.

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