CBD lengthens sleep but shortens ripples and leads to intact simple but worse cumulative memory

Summary & key facts

Researchers gave oral cannabidiol, or CBD, to rats and tested two kinds of memory. CBD made the rats sleep for a longer time. But it also changed sleep brain waves and reduced a specific fast brain wave called a ripple. That change was linked to worse memory that needs combining information across days, while simple one-time memories stayed normal. These results show CBD can help sleep but might harm some kinds of memory, at least in rats, and we do not know if the same happens in people.

Key facts:

• The study used two experiments in rats and tested memory with an object space task that looks at simple memories and cumulative memories built over time.
• Giving CBD by mouth made the rats sleep for a longer overall period.
• CBD changed properties of rest and non-REM sleep brain waves, including slow waves called delta, short bursts called spindles, and fast events called ripples.
• CBD specifically led to fewer long ripples lasting more than 100 milliseconds.
• The drop in long ripples was linked to worse consolidation of cumulative memory, meaning rats were worse at forming memories that build up over repeated learning.
• Simple memories that do not rely on repeated learning were not affected by CBD in these experiments.
• All results come from rats, so we cannot assume the same effects happen in humans without more research.

Abstract

Cannabidiol (CBD) is on the rise as over-the-counter medication to treat sleep disturbances, anxiety, pain, and epilepsy due to its action on the excitatory/inhibitory balance in the brain. However, it remains unclear if CBD also leads to adverse effects on memory via changes of sleep macro- and microarchitecture. To investigate the effect of CBD on sleep and memory consolidation, we performed two experiments using the object space task testing for both simple and cumulative memory in rats. We show that oral CBD administration extended the sleep period but changed the properties of rest and non-REM sleep oscillations (delta, spindle, ripples). Specifically, CBD also led to less long (>100 ms) ripples and, consequently, worse cumulative memory consolidation. In contrast, simple memories were not affected. In sum, we can confirm the beneficial effect of CBD on sleep; however, this comes with changes in oscillations that negatively impact memory consolidation.

Topics

Cannabis and Cannabinoid Research Neuroscience and Neuropharmacology Research Sleep and Wakefulness Research

Categories

Cognitive Neuroscience Life Sciences Neuroscience

Tags

Anesthesia Anxiety Computer science Electroencephalography Epilepsy Excitatory postsynaptic potential Hippocampus Inhibitory postsynaptic potential Medicine Memory consolidation Neuroscience Operating system Psychiatry Psychology Sleep (system call) Sleep spindle Slow-wave sleep

Substances

Cannabis

Conditions & symptoms

Anxiety Chronic Pain Sleep disorder Anxiety or worry Chronic pain Poor sleep