[THE EFFECT OF MOTION SICKNESS ON THE SLEEP-WAKE CYCLE IN RATS EXPOSED TO PRENATAL HYPOXIA]

Area of Science:

• Neuroscience
• Sleep Medicine
• Developmental Neuroscience

Background:

• Motion sickness (MS) and its relationship with sleep-wake cycle (SWC) changes are not fully understood.
• Prenatal hypoxia is a known factor affecting neurodevelopment and could influence MS and SWC.
• The sopite syndrome, a potential manifestation of MS, requires further investigation.

Purpose of the Study:

• To investigate the effects of MS on SWC in rats.
• To examine the influence of prenatal hypoxia on MS-induced SWC alterations.
• To explore the hypothalamic mechanisms linking MS and SWC and their role in the sopite syndrome.

Main Methods:

• Studied SWC in 30-day-old intact rats and rats exposed to prenatal hypoxia (gestation days 13 and 19).
• Induced MS in experimental groups.
• Analyzed changes in waking time, paradoxical sleep (PS), and slow-wave sleep.

Main Results:

• MS significantly reduced waking time and increased PS duration in all rat groups.
• Prenatal hypoxia on day 19 of gestation had a more detrimental effect on thalamocortical sleep-regulating structures than on day 13.
• MS suppressed brain excitatory systems maintaining wakefulness and enhanced systems controlling PS, particularly in rats with day 19 prenatal hypoxia exposure.

Conclusions:

• A connection exists between hypothalamic mechanisms controlling MS and SWC, potentially underlying the sopite syndrome.
• Prenatal hypoxia on day 19 of gestation disrupts thalamocortical systems more severely than on day 13.
• The evolutionary young thalamocortical system plays a role in PS control, especially under conditions of MS and prenatal hypoxia.