Bioscience

Genetic Base for Difference of Human Brain Size Discovered

Recently, a research group headed by Su Bing, Research Fellow from the State Key Laboratory of Genetic Resources and Evolution of the Kunming Institute of Zoology, CAS has discovered that a variation of single base in the genome, known as single nucleotide polymorphism (SNP), influences brain size in the Chinese human groups. This SNP existing in MCPH1 is a base pair change from T to C that corresponds to an amino acid change from valine to alanine. The corresponding allele frequency among population is around 36 percent. The haplotype analysis confirmed the association of rs1057090 with cranial volume, and the homozygote males containing the derived alleles of rs1057090 have larger cranial volumes compared with those containing the ancestral alleles. No recent selection signal can be detected on this SNP, suggesting that the brain volume variation in human populations is likely neutral or under very weak selection in recent human history.

It is the first time to discover the sequence variation related to the brain size difference among the homozygote population. It will help elucidate the human brain evolvement and the genetic mechanism of the human neurological disorder. The feat has been published on the Human Molecular Genetics.

Green Tea Polyphenols to Control Parkinson's

A research team led by Prof. Zhao Baolu from the State Key Laboratory of Brain & Cognitive Science affiliated to the CAS Institute of Biophysics, investigated the effects of green tea polyphenols, a group of naturally occurring chemical substances found in plants that have antioxidant properties, in an animal model of Parkinson's disease. Their work has been reported by the Dec.15 issue of Biological Psychiatry under the title of “Protective effect of green tea polyphenols on rat model of Parkinson’s disease caused by 6-OHDA through ROS-NO pathway”. The journal also published a press release entitled “Green Tea May Protect Brain Cells against Parkinson's”.

Parkinson's disease is a progressive, degenerative disorder of the central nervous system, resulting from the loss of dopamine-producing brain cells, and the symptoms include tremors, muscular rigidity, impaired mobility, etc. After several years of research over the molecular mechanism of degenerative diseases of the central nervous system and the natural anti-oxidants’ treatment of such diseases, the research team found that the green tea polyphenols protected against the toxic effects of 6-OHDA, with the higher dose producing a higher protective effect. Most notable, were the inhibition of increases in ROS and NO levels, and subsequent lipid peroxidation. After systematic research on the characteristics, structures and functions of the green tea polyphenols, researchers focused their research on the natural anti-oxidant’s functions of prevention against and treatment of Parkinson's in the cell and animal models. They elucidated the molecular mechanism and signal pathway with protective effects of green tea polyphenols against 6-OHDA-induced Parkinson's disease. The discovery was granted the national patent for invention in 2007.