Activity, Motor Control & Coordination
Pain - Thermal Allodynia / Hyperalgesia
Pain - Spontaneous Pain - Postural Deficit
Pain - Mechanical Allodynia / Hyperalgesia
Anxiety & Depression Disorder
Learning/Memory - Attention - Addiction
Physiology & Respiratory Research
Metabolism - Food & Drink Intake
Pain
Metabolism
Motor control
Neurodegeneration
Cross-disciplinary subjects
Muscular system
General activity
Mood Disorders
Other disorders
Joints
Central Nervous System (CNS)
Sensory system
Authors
M. Steiner, H. Lecourt, D. Strasser, C. Brisbare-Roch, F. Jenck.
Lab
Actelion Pharmaceuticals Ltd, CNS-Pharmacology, Allschwil, Switzerland.
Journal
Neuropsychopharmacology
Abstract
Current insomnia treatments such as _-aminobutyric acid (GABA) receptor modulators are associated with sedative and muscle-relaxant effects, which increase when drug intake is combined with alcohol. This study compared the novel sleep-enabling compound almorexant (ACT-078573-hydrochloride), a dual orexin receptor antagonist, with the positive GABA(A)-_1 receptor modulator zolpidem. Both compounds were administered alone or in combination with ethanol, and their effects on forced motor performance were determined in Wistar rats upon waking after treatment. To detect substance-induced sedation and myorelaxation, time spent on an accelerating rotating rod (rotarod) and forepaw grip strength were measured. Zolpidem (10, 30, and 100_mg/kg, p.o.) and ethanol (0.32, 1, and 1.5_g/kg, i.p.) dose-dependently decreased rotarod performance and grip strength, whereas almorexant (30, 100, and 300_mg/kg, p.o.) did not. Doses of ethanol (0.32 and 1_g/kg), which were ineffective when administered alone, showed interactions with zolpidem (10 and 30_mg/kg) leading to reduced rotarod performance and grip strength; in contrast, combination of ethanol (0.32 and 1_g/kg) with almorexant (100 and 300_mg/kg) did not reduce performance or grip strength below ethanol alone. We conclude that unlike zolpidem, almorexant does not interfere with forced motor performance or grip strength in the rat, nor does it further increase the sedative effects of ethanol. Our results suggest that the effect of almorexant can be immediately reversed to full alertness like under physiological sleep, and that almorexant is less likely to show strong sedation, excessive myorelaxation, or interaction with alcohol than commonly prescribed hypnotics such as zolpidem.
BIOSEB Instruments Used:
Grip strength test (BIO-GS3)
