A new study from the Montreal Neurological Institute (MNI) at McGill University demonstrates interestingly, that sleep-wake states are regulated by two different types of nerve cells (neurons), melanin-concentrating hormone (MCH) neurons and orexin (Orx) neurons, which occupy the same region of the brain but perform opposite functions.

The MNI study is the first to discover that MCH neurons are activated during sleep and could thus be important in regulating the sleep state. The study, published in this week’s issue of the journal Proceedings of the National Academy of Sciences (PNAS), provides deeper understanding of the sleep-wake cycle and vital insight into the basis of sleep disorders such as narcolepsy and possibly also other diseases such as depression and Parkinson’s.

Sleep is regulated by processes in the brain in response to how long we are awake in addition to the light/dark cycle controlled by the circadian rhythm.

With Drs. Oum Hassani and Maan Gee Lee, Dr. Barbara Jones at the MNI were studying a structure in the brain called the lateral hypothalamus (LH) known to be critical for maintaining wakefulness.

MCH neurons, co-distributed with Orx neurons, constitute less than 10% of the LH.

Previous studies have shown that Orx neurons are essential for maintenance of the awake state. These neurons are active in the waking state and turn off during sleep and in their absence, animals and humans experience narcolepsy with cataplexy or sudden loss of muscle tone.

However, the role of MCH neurons was until now, unclear. Evidence from earlier knockout studies suggested that MCH neurons might play a different role than Orx neurons in regulating activity and sleep-wake states.

Therefore the team at the MNI set up experiments to study the function of MCH neurons during the sleep-wake states.

“Remarkably, what we found is that MCH neurons are actually silent during waking, which is a surprising finding especially in this wake-promoting region of the brain.

The neurons fire during sleep, and are most active during REM sleep,” says Dr. Barbara Jones, neuroscientist at the MNI and principal investigator in the study. “Our study markedly demonstrates that MCH neurons discharge in a reciprocal manner to the Orx neurons across the sleep-wake cycle.”

Dr. Jones and colleagues used their expertise to apply and develop a difficult technique which allowed them to selectively record, label and thus identify a nerve cell containing a particular chemical. This allowed them to isolate the functions of the MCH and Orx cells even though they comprise less than 10% of the nerve cells in the LH.

The reciprocal profiles and roles of the Orx and MCH neurons could be significant in the manifestation of sleep disorders.

It is possible that narcolepsy, which occurs with the loss of Orx neurons, is provoked in part by the MCH neurons that remain intact in the narcoleptic patients. A growing body of research shows that regular and normal sleep is necessary for overall health; regulating hormone levels, blood pressure, metabolism, alertness, mood, and consolidating memory.

This study presents potential therapeutic avenues and targets for the treatment of various sleep disorders including the development of drugs that will act on receptors for Orx and MCH, to stimulate or block these receptors accordingly.

(Source: McGill University: Proceedings of the National Academy of Sciences: March 2009)

http://www.virtualmedicalcentre.com

Well, now the folks at Nature are at it again, this time with an opinion piece supporting the idea of brain boosters.

“we should welcome new methods of improving our brain function,” the authors wrote, saying that using drugs to do so is no more immoral than it is to eat right or get a good night’s sleep.

The Nature commentary calls for more research into these alternative uses and offers some tips for managing the risks.

It makes sense to take a reasonable approach to the idea, one of the authors said, because as baby boomers age, they’re going to want to keep their brains agile. “Almost everybody is going to want to use it,” Martha Farah told the AP.

“I would be the first in line if safe and effective drugs were developed that trumped caffeine,” another told the news service, reminding us that coffee became the brain-booster of choice during the Enlightenment, when thinkers such as Rousseau and Voltaire would slam down upwards of 20 espressos a day to get their writing done.

Could Ritalin, Adderall and other ADHD drugs–plus anti-narcoleptics such as Provigil–be the next wave of socially acceptable stimulators? We’ll have to wait and see. But given the world of deadlines and distractions we navigate daily, there’s likely to be plenty of demand if and when the time comes.

- read the AP story

Related Articles:
Pros use pills to boost brainpower
Provigil study sparks debate
Provigil–Top 10 Warnings and Recalls

http://www.fiercepharma.com

According to the National Institute of Mental Health, about 3 to 5 percent of the general population has the disorder, which is characterized by agitated behavior and an inability to focus on tasks.

Methylphenidate also is occasionally prescribed for treating narcolepsy.

Health Effects
Methylphenidate is a central nervous system (CNS) stimulant. It has effects similar to, but more potent than, caffeine and less potent than amphetamines. It has a notably calming effect on hyperactive children and a “focusing” effect on those with ADHD.

Recent research at Brookhaven National Laboratory may begin to explain how methylphenidate helps people with ADHD.

The researchers used positron emission tomography (PET – a noninvasive brain scan) to confirm that administering normal therapeutic doses of methylphenidate to healthy, adult men increased their dopamine levels.

The researchers speculate that methylphenidate amplifies the release of dopamine, a neurotransmitter, thereby improving attention and focus in individuals who have dopamine signals that are weak, such as individuals with ADHD.

When taken as prescribed, methylphenidate is a valuable medicine. Research shows that people with ADHD do not become addicted to stimulant medications when taken in the form prescribed and at treatment dosages.

Another study found that ADHD boys treated with stimulants such as methylphenidate are significantly less likely to abuse drugs and alcohol when they are older than are non-treated ADHD boys.

Because of its stimulant properties, however, in recent years there have been reports of abuse of methylphenidate by people for whom it is not a medication.

Some individuals abuse it for its stimulant effects: appetite suppression, wakefulness, increased focus/attentiveness, and euphoria.

When abused, the tablets are either taken orally or crushed and snorted. Some abusers dissolve the tablets in water and inject the mixture – complications can arise from this because insoluble fillers in the tablets can block small blood vessels.

Trends in Ritalin Abuse
At their June 2000 meeting, members of NIDA’s Community Epidemiology Work Group (CEWG)* shared the following information.

The abuse of methylphenidate has been reported in Baltimore, mostly among middle and high schools students; Boston, especially among middle and upper-middle class communities; Detroit; Minneapolis/St. Paul; Phoenix; and Texas.

When abused, methylphenidate tablets are often used orally or crushed and used intranasally.

In 1999, 165 methylphenidate-related poison calls were made in Detroit; 419 were reported in Texas, with 114 of those involving intentional misuse or abuse.

On Chicago’s South Side, some users inject methylphenidate (this is referred to as “west coast”). Also, some mix it with heroin (a “speedball”) or in combination with both cocaine and heroin for a more potent effect.

Because stimulant medicines such as methylphenidate do have potential for abuse, the U.S. Drug Enforcement Administration (DEA) has placed stringent, Schedule II controls on their manufacture, distribution, and prescription. For example, DEA requires special licenses for these activities, and prescription refills are not allowed. States may impose further regulations, such as limiting the number of dosage units per prescription.

For more information on the entire spectrum of popularly abused prescription drugs, check out the following link;

http://www.prescription-drug-abuse.org