Prenatal cocaine alters normoxic sleep-wake and diaphragmatic EMG patterns in piglets
✍ Scribed by Immanuela R. Moss; André Laferrière
- Book ID
- 101268801
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 135 KB
- Volume
- 25
- Category
- Article
- ISSN
- 8755-6863
No coin nor oath required. For personal study only.
✦ Synopsis
This study assessed in piglets the effects of prenatal cocaine administration on sleep-wake states (SWS) and respiratory parameters, utilizing diaphragmatic electromyogram (EMG di ) recordings during normoxia before and after hypoxia (0.10 F I,O 2 , 10 min). We asked whether the respiratory effects were linked to a specific SWS, and whether there was a difference in respiratory measures between the two normoxic conditions. Unsedated, chronically instrumented 3-9-or 21-31-day-old piglets, representing distinct stages in developmental respiratory control, were used.
In pre-hypoxic normoxia, prenatal piglets, cocaine enhanced sleep at the expense of wakefulness and increased EMG di amplitude, slope, and area under the integrated envelope (EMG di , area) in both age groups regardless of SWS; after hypoxic exposure, the respiratory findings persisted in the young group, but disappeared in the older group. In the young group and regardless of SWS, interbreath interval (t tot ) and expiratory duration (t tot -t EMG di [duration of EMG di ]) were shorter in the cocaine-exposed than in the unexposed piglets, and t tot , t EMG di , and (t tot -t EMG di ) decreased from pre-to post-hypoxic normoxia. In the older group, t tot and (t tot t EMG di ) differed among SWS, but were unaffected by drug treatment; t EMG di was higher with cocaine exposure in pre-, but not in post-hypoxic normoxia, and two-thirds of the EMG di measurements during post-hypoxic normoxia exhibited a similar magnitude in the drug-treated and untreated groups regardless of SWS. We conclude that 1) prenatal cocaine alters both SWS and EMG di , but the EMG di effects are independent of SWS; and 2) the similar EMG di patterns in the older group after hypoxia, regardless of drug treatment, suggest that hypoxia and chronic prenatal cocaine might alter EMG di by similar mechanisms.