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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

A caudal-to-rostral subset of photomicrographs, taken from the complete series of midbrain coronal sections, showing darkly stained cell bodies evenly distributed throughout the medial–lateral aspect of the locus coeruleus. The low-power (2.5×) insert on each photomicrograph indicates the caudal-to-rostral level of the higher-power (10×) enlargement. (A) Higher densities of TH-ir cells are found at the more caudal sites. The scale bar is the same on three of the photomicrographs and applies to the high-power (10×) picture. (B) At this level, fewer TH-ir cells are seen. The insert shows a higher-power (63×) view of a pair of TH-ir cells. Their location in the 10× section is indicated by the dotted line connecting the two boxes. (C) The most rostral section has the fewest TH-ir cells. 3v designates the third ventricle.
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Figure 3: A caudal-to-rostral subset of photomicrographs, taken from the complete series of midbrain coronal sections, showing darkly stained cell bodies evenly distributed throughout the medial–lateral aspect of the locus coeruleus. The low-power (2.5×) insert on each photomicrograph indicates the caudal-to-rostral level of the higher-power (10×) enlargement. (A) Higher densities of TH-ir cells are found at the more caudal sites. The scale bar is the same on three of the photomicrographs and applies to the high-power (10×) picture. (B) At this level, fewer TH-ir cells are seen. The insert shows a higher-power (63×) view of a pair of TH-ir cells. Their location in the 10× section is indicated by the dotted line connecting the two boxes. (C) The most rostral section has the fewest TH-ir cells. 3v designates the third ventricle.

Mentions: Stereological analysis furnished unbiased estimates of total area and volume of the LC as well as of size, number, and density of TH-ir cells within the nucleus (Figure 3). The effect of REMSD on these measures reached significance for total number of TH-ir cells (Figure 4, F = 4.3, df = 2.9, p = 0.049),indicating that RD animals had fewer TH-ir cells than TXC animals (post hoc Bonferroni corrected t-tests, p = 0.05). Cell number in the HCC group was numerically larger than in animals subjected to REMSD. The HCC value, however, did not differ significantly from cell number in either RD or TXC kittens (Figure 4).


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)

A caudal-to-rostral subset of photomicrographs, taken from the complete series of midbrain coronal sections, showing darkly stained cell bodies evenly distributed throughout the medial–lateral aspect of the locus coeruleus. The low-power (2.5×) insert on each photomicrograph indicates the caudal-to-rostral level of the higher-power (10×) enlargement. (A) Higher densities of TH-ir cells are found at the more caudal sites. The scale bar is the same on three of the photomicrographs and applies to the high-power (10×) picture. (B) At this level, fewer TH-ir cells are seen. The insert shows a higher-power (63×) view of a pair of TH-ir cells. Their location in the 10× section is indicated by the dotted line connecting the two boxes. (C) The most rostral section has the fewest TH-ir cells. 3v designates the third ventricle.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: A caudal-to-rostral subset of photomicrographs, taken from the complete series of midbrain coronal sections, showing darkly stained cell bodies evenly distributed throughout the medial–lateral aspect of the locus coeruleus. The low-power (2.5×) insert on each photomicrograph indicates the caudal-to-rostral level of the higher-power (10×) enlargement. (A) Higher densities of TH-ir cells are found at the more caudal sites. The scale bar is the same on three of the photomicrographs and applies to the high-power (10×) picture. (B) At this level, fewer TH-ir cells are seen. The insert shows a higher-power (63×) view of a pair of TH-ir cells. Their location in the 10× section is indicated by the dotted line connecting the two boxes. (C) The most rostral section has the fewest TH-ir cells. 3v designates the third ventricle.
Mentions: Stereological analysis furnished unbiased estimates of total area and volume of the LC as well as of size, number, and density of TH-ir cells within the nucleus (Figure 3). The effect of REMSD on these measures reached significance for total number of TH-ir cells (Figure 4, F = 4.3, df = 2.9, p = 0.049),indicating that RD animals had fewer TH-ir cells than TXC animals (post hoc Bonferroni corrected t-tests, p = 0.05). Cell number in the HCC group was numerically larger than in animals subjected to REMSD. The HCC value, however, did not differ significantly from cell number in either RD or TXC kittens (Figure 4).

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