Rapid eye movement sleep and neuronal development.

PURPOSE OF REVIEW: To understand the importance of rapid eye movement (REM) sleep in the cognitive and sensorimotor development via neural plasticity during embryonic development and infants. RECENT FINDINGS: REM sleep has remained a mystery as many of the underlying mechanisms of REM sleep remain unclear. Recent findings have demonstrated that REM sleep selectively prunes newly formed dendritic spines in the developing brain as well as strengthening new synapses in the developing brain. This process is critical for normal neuronal circuit development and behavioral improvement after learning. SUMMARY: Although many mechanisms of REM sleep remain unclear, recent findings strongly suggest that REM sleep is vitally important in pruning synapses as well as maintaining new synapses for the development of a healthy brain. Developmental neuroplasticity refers to the continuous change of the developing brain during fetal development. Lack of plasticity may result in reduced intellectual ability, reduced learning and memory consolidation, and mental illness.

Roles of gender, age, race/ethnicity, and residential socioeconomics in obstructive sleep apnea syndromes.

PURPOSE OF REVIEW: Review recent research on the roles of gender, race/ethnicity, residential socioeconomics and age in obstructive sleep apnea syndromes (OSA) and their treatment. RECENT FINDINGS: Men have a higher prevalence of OSA than women and require higher continuous positive airway pressure (CPAP) pressures for treatment, given similar severity of OSA. When comparing age, women have less severe apnea at all ages. Menopause, pregnancy and polycystic ovarian syndrome increase the risk for OSA in women. Neck fat and BMI influence apnea-hypopnea index (AHI) severity in women; abdominal fat and neck-to-waist ratio do so in men. Obesity, craniofacial structure, lower socioeconomic status and neighborhood disadvantage may better explain ethnic/racial differences in the prevalence and severity of OSA. Ethnicity was no longer significantly associated with OSA severity when WHO criteria for obesity were used. SUMMARY: OSA has a male predominance; women have a lower AHI than men during certain stages of sleep; women require less CPAP pressure for treatment of similar severity of OSA, and there are ethnic/racial differences in the prevalence and severity of OSA but these may be due to environmental factors, such as living in disadvantaged neighborhoods.