| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4351535 | Neuroscience Research | 2013 | 6 Pages |
•Brain Fos expression was analyzed in sleep apnea (SA) model using db/db mice.•Intermittent hypoxia (IH) reduced Fos expression in the paralimbic cortices.•IH also reduced Fos expression in the amygdala, accumbens, ventral tegmental area.•Fos expression in the brain stem structures was relatively resistant against IH.•Suppression of limbic and paralimbic activities may be linked to central SA symptoms.
Sleep apnea (SA) causes not only sleep disturbances, but also neurocognitive impairments and/or psychoemotional disorders. Here, we studied the effects of intermittent hypoxia (IH) on forebrain Fos expression using obese diabetic db/db mice to explore the pathophysiological alterations in neural activities and the brain regions related to SA syndrome. Male db/db mice were exposed to IH stimuli (repetitive 6-min cycles of 1 min with 5% oxygen followed by 5 min with 21% oxygen) for 8 h (80 cycles) per day or normoxic condition (control group) for 14 days. Fos protein expression was immunohistochemically examined a day after the last IH exposure. Mapping analysis revealed a significant reduction of Fos expression by IH in limbic and paralimbic structures, including the cingulate and piriform cortices, the core part of the nucleus accumbens and most parts of the amygdala (i.e., the basolateral and basomedial amygdaloid nuclei, cortical amygdaloid area and medial amygdaloid nucleus). In the brain stem regions, Fos expression was region-specifically reduced in the ventral tegmental area while other regions including the striatum, thalamus and hypothalamus, were relatively resistant against IH. In addition, db/db mice exposed to IH showed a trend of sedative and/or depressive behavioral signs in the open field and forced swim tests. The present results illustrate that SA in the obese diabetic model causes neural suppression preferentially in the limbic and paralimbic regions, which may be related to the neuropsychological disturbances associated with SA.
