Marijuana Time Warp

[Ganjarden]

People who smoke pot can feel lost in time—for some, it's part of the draw. Now researchers may have figured out one reason why cannabinoids, the psychoactive compounds in marijuana and hashish, make people feel this way; they disrupt the body's internal clock.

Sleeping, eating, and other activities are all part of a 24-hour physiological cycle known as the circadian rhythm. This internal clock is controlled by neurons in a region of the brain called the suprachiasmatic nucleus (SCN). The SCN normally uses light to reset the clock. That's what happens when you travel from one time zone to another. But absent any sensory input, SCN neurons will still maintain a circadian rhythm: People and animals kept in total darkness continue to eat and sleep at the usual times.

Several years ago, researchers discovered that SCN neurons possess receptors for cannabinoids. In the new study, a team led by Yale University circadian biologist Anthony van den Pol tried to figure out what role these receptors play.

The researchers housed 42 mice in total darkness for 2 weeks to synchronize their internal clocks. In this environment the animals cycled through active and inactive phases lasting about 12 hours each. After 2 weeks, the researchers shined a light into some of the cages shortly after the mice had entered their active phase. Because mice are nocturnal, they became active about 2 hours later in the day than did mice not exposed to light, a phenomenon called "phase delay." But mice given brain injections of cannabinoids before light exposure exhibited much less of a phase delay; they became active only 1 hour later than did animals not exposed to light.

The researchers then looked at the SCN cells themselves. When they added cannabinoids to mouse SCN cells in a petri dish, the cells fired about 50% more frequently. This increased activity likely mucks up the circadian rhythm in a live mouse, the researchers reported online this week in The Journal of Neuroscience.

The team believes cannabinoids may have a similar effect in humans. People tend to lose track of time when they smoke pot, van den Pol says. That may be because the cannabinoids in the drug cause their SCN neurons to fire erratically, he says, disrupting their internal clock.

Joseph Bass, a circadian researcher at Northwestern University in Evanston, Illinois, says the work supports the idea that addictive substances can impact the body's circadian rhythm. Anecdotally, this may seem obvious, but until recently studies of addictive substances focused only on the brain's reward system. Evidence that molecules can impact both the reward system and the circadian system is just emerging, Bass says.


NewsHawk: Ganjarden: 420 MAGAZINE
Source: ScienceNOW
Author: Nazlie Latefi
Contact: ScienceNOW
Copyright: 2010 American Association for the Advancement of Science.
Website: Marijuana Time Warp

[Herb Zen]

All I know is, even if I smoke a ton before going to bed,, I still wake up at 5am every day,,, (haven't used an alarm clock since high school, and even then it was just the alarm on my digital watch)

maybe the effects wear off before I wake up, and my internal clock gets reset? or it just doesn't effect my clock,,


interesting article though,, it is good to see research on other areas of pot being done..

[SnowBender]

So why do I keep waking up at 4:20 am?

[Mama Train]

Originally Posted by SnowBender

So why do I keep waking up at 4:20 am?

I know why...cause i do 2. Twice the fun!
interesting read. Im an artist and i love to lose track of time. It helps the creative flow.
but really....I have DJD and replaced three joints in my 50's. That very effect is why im still walkin. i concentrate on the other joys of the walk, lose track of time, forget to think about pain. my dr agrees this must b why im not in a wheelchair. he sez keep walkin no matter what it takes. the oxy sent me 2 bed and thigs got so much worse, recovery took so long. started smokin an walkin and now i can work again. hard 2 view weed as evil when it does so much good. im not gunna die like michael and anna.

[Joe Curwen]

One thing that irritates me about many brief abstracts of scientific research is lack of citation. If one reviews a paper, one should provide the publication information. Spare the reader from having to track it down.

Cannabinoids excite circadian clock neurons. [J Neurosci. 2010] - PubMed result