HONG KONG: Researchers inquiring into the popular youth-cult drug Ketamine have discovered that abusers, who mix the horse tranquilizer with alcohol, increase damage to their brain by 50 percent.

Ketamine is popular in Hong Kong's youth drug culture. That culture came under the glare of public scrutiny after several incidents in which secondary students were found unconscious under the influence of ketamine, in public places.

Professor David Yew Tai-wai presented his findings yesterday, just prior to the inauguration of the Chinese University of Hong Kong School of Biomedical Science.

Yew told reporters that more than six months of laboratory tests on mice demonstrated that brain cell mortality shot up by half after alcohol was introduced alongside ketamine.

"The mice were fed the human equivalent of less than one gram daily, which is much less than most recreational users abuse at a time. After we introduced the equivalent of two glasses of red wine, we found the rate at which brain tissue died off rose from six dead cells per 1,500 micrometers squared to 11 dead cells per 1,500 micrometers squared," he said.

The study which was conducted on 100 mice had a 20 percent fatality rate and nearly all the deaths were caused by severe liver or brain damage, leading to autonomic failure, Yew said.

"This is where the brain is no longer able to control automatic functions such as heart rate and breathing," he said.

The study also looked at MRI brain scans of Ketamine and heroin users and found areas of the brain that control spatial memory and desires were affected, leading to hallucinations and predispositions to addiction respectively.

Ketamine also affected the corpus striatum, the portion of the brain responsible for fine-tuning motor functions and movement.

Using more than a dozen test subjects, Yew tracked a sharp decrease in brain activity in heroin users around the motor cortex when subjects were asked to connect opposing fingers.

"The level and areas of brain damage from Ketamine and heroin usage can lead to diminished voluntary movements and an increase of involuntary movements such as shaking. The involuntary effects are similar to having chorea on the one hand and on the other, an inability to control basic movement as in the case of Parkinson's Disease," he said.

British researchers also established Ketamine can cause irreversible bladder damage. In a 2008 study published in the British Medical Journal, researchers reported users had complications urinating and that damage to bladder linings can also spread to the kidneys.

The university's School of Biomedical Science will look to enroll 150 students for the coming academic year.

(HK Edition 01/09/2010 page1)