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WASHINGTON, Dec. 7 (Xinhua) -- Drugs that affect the levels of an important brain protein involved in learning and memory reverse cellular changes in the brain seen during aging, according to an animal study published Wednesday in the Journal of Neuroscience. The findings could one day aid in the development of new drugs that enhance cognitive function in older adults.Aging-related memory loss is associated with the gradual deterioration of the structure and function of synapses (the connections between brain cells) in brain regions critical to learning and memory, such as the hippocampus.Recent studies suggested that histone acetylation, a chemical process that controls whether genes are turned on, affects this process. Specifically, it affects brain cells' ability to alter the strength and structure of their connections for information storage, a process known as synaptic plasticity, which is a cellular signature of memory.In the current study, Cui-Wei Xie, of the University of California, Los Angeles, and colleagues found that compared with younger rats, hippocampi from older rats have less brain-derived neurotrophic factor (BDNF) -- a protein that promotes synaptic plasticity -- and less histone acetylation of the Bdnf gene. By treating the hippocampal tissue from older animals with a drug that increased histone acetylation, they were able to restore BDNF production and synaptic plasticity to levels found in younger animals."These findings shed light on why synapses become less efficient and more vulnerable to impairment during aging," said Xie, who led the study. "Such knowledge could help develop new drugs for cognitive aging and aging-related neurodegenerative diseases, such as Alzheimer's disease," she added.

JERUSALEM, Oct. 24 (Xinhua) -- A recent study carried out by Israeli researchers showed that the experience of motherhood is caused by alterations in the brain functions that help mothers locate and communicate with their offspring, especially if they are in distress.Researchers at the Hebrew University of Jerusalem said the results provide insight into how neural changes in response to odors and sounds help maternal behaviors develop in mothers."We know that distinct brain changes are linked with motherhood, " Dr. Adi Mizrahi, who conducted the research, said, "but the impact of these changes on sensory processing and the emergence of maternal behaviors are largely unknown."Mizrahi and his colleagues examined whether the primary auditory cortex -- a region in the brain that is involved in the recognition of sounds -- might serve to process the responses to their offspring's specific smell and voice.The research proved that the olfactory and auditory senses of female mice with their pups were triggered immediately after they gave birth, with especially strong responses to cries of distress."These processes help to explain how changes in the cortex in the brain facilitate efficient detection of pups," Mizrahi said.

ISLAMABAD, Oct. 15 (Xinhua) -- President Asif Ali Zardari said on Saturday that the government was committed to address the issues of special people including those afflicted with impaired vision and blindness and called for establishing highest standards for their care.In a message on the International White Cane Safety Day, the President asked the people and relevant government agencies to reflect on the problems of visually handicapped people.He asked them to come up with suggestions to achieve high standards in caring for the disabled as these exist in other civilized nations.The White Cane Safety Day was aimed at creating awareness about the problems and requirements of visually handicapped persons and to take practical steps to address these issues. Enditem

WASHINGTON, Oct. 18 (Xinhua) -- Scientists have increased the estimate of the number of humpback whales in the North Pacific Ocean, according to a paper published Tuesday in the Marine Mammal Science journal.The increase follows a refined statistical analysis of data compiled in 2008 from the largest whale survey ever carried out to appraise humpback whale populations throughout the North Pacific.The number of North Pacific humpback whales in the 2008 study, known as the Structure of Populations, Levels of Abundance and Status of Humpbacks, or SPLASH, was estimated at just under 20,000 based on a preliminary look at the data.The latest research indicates the population to be over 21,000 and possibly even higher -- a significant improvement to the scant 1,400 humpback whales estimated in the North Pacific Ocean at the end of commercial whaling in 1966."These improved numbers are encouraging, especially after we have reduced most of the biases inherent in any statistical model," said Jay Barlow, marine mammal biologist of the U.S. National Oceanic and Atmospheric Administration (NOAA)."We feel the numbers may even be larger since there have been across-the-board increases in known population areas and unknown areas have probably seen the same increases," Barlow added.The SPLASH research was a three-year project started in 2004 involving NOAA scientists and hundreds of other researchers from the United States, Japan, Russia and some other countries.It was the first systematic survey ever attempted to determine the humpback whales' overall population, structure and genetic makeup in the North Pacific.

WASHINGTON, Nov. 10 (Xinhua) -- The U.S. Food and Drug Administration (FDA) has sent warning letters to more than 1,200 retailers, the majority of which respond to violations relating to selling tobacco to minors, as part of its ongoing effort to reduce tobacco use among children, the agency announced Thursday in a statement.The FDA said that while most retail establishments have been found to be in compliance with the law, some retailers are still selling cigarettes and smokeless tobacco to minors. Warning letters may be followed by civil money penalties if retailers continue to violate the law."It should worry every parent that 20 percent of U.S. high school students smoke cigarettes," said FDA Commissioner Margaret Hamburg in a statement. "President Obama and the FDA are committed to preventing children from smoking. For many young people, that first cigarette or use of smokeless tobacco will lead to a lifetime of addiction, and for many, serious disease. More than 80 percent of adult smokers begin smoking before 18 years of age. Retailers are vital partners in the FDA's efforts to prevent tobacco use among kids."Obama signed the Family Smoking Prevention and Tobacco Control Act that gives the FDA authority to regulate tobacco products to prevent use by minors and reduce the impact on public health. One of the law's provisions permits the FDA to contract with states and territories to conduct compliance check inspections of tobacco retailers. In 2011, the FDA awarded compliance contracts totaling more than 24 million U.S. dollars to 38 states.The FDA also began inspecting U.S. tobacco product manufacturers in October 2011. This is the first time tobacco product manufacturing facilities have ever been inspected by a federal public health agency.