LSD and tryptamine effects on sleep/wakefulness and electrocorticogram patterns in intact cats

Area of Science:

• Neuroscience
• Pharmacology
• Sleep Research

Background:

• Psychoactive substances like LSD and tryptamine are known to affect brain activity.
• Understanding their impact on sleep-wake cycles is crucial for neuroscience and pharmacology.
• Previous research has explored the effects of various compounds on animal models.

Purpose of the Study:

• To compare the effects of lysergic acid diethylamide (LSD) and tryptamine on sleep and waking patterns in cats.
• To analyze electrocorticogram (ECoG) changes induced by these substances.
• To investigate dose-dependent effects and temporal patterns of these drugs on feline sleep architecture.

Main Methods:

• Intravenous infusions of LSD and tryptamine were administered to intact cats in a crossover design.
• Sleep and waking patterns were observed, alongside electrocorticogram (ECoG) analysis for frequency band indices, mean amplitude, and frequency.
• Comparisons were made against saline controls across different infusion periods.

Main Results:

• LSD increased wakefulness and drowsiness while decreasing spindle sleep and REM sleep.
• Tryptamine also increased wakefulness and drowsiness, decreasing spindle and REM sleep, with effects diminishing after infusion cessation.
• Both substances altered ECoG parameters, with LSD increasing delta index and amplitude, and decreasing frequency, while tryptamine increased ECoG frequency and amplitude.

Conclusions:

• Both LSD and tryptamine significantly alter sleep-wake patterns in cats, primarily by increasing wakefulness and reducing spindle and REM sleep.
• The observed changes in ECoG activity indicate distinct but overlapping neurophysiological effects of LSD and tryptamine.
• These findings contribute to understanding the neurobiological mechanisms underlying the effects of serotonergic psychedelics on sleep and consciousness.