Scientists: ‘Smell of fear’ is linked to compound

Scientists from The Scripps Research Institute have found a chemical compound secreted by predators that provokes a fear response in mice.

Mice — even those that have never before encountered other species — will act fearfully when exposed to the odor of cats, rats, snakes, ferrets, weasels and foxes. Mice have two sensory organs: the vomeronasal organ (VNO), located above the roof of the mouth in the nasal cavity; and the main olfactory epithelium (MOE), found under the eyeball at the top back portion of the nasal cavity.

When normal (wildtype) mice possessing both sensory organs were placed in a cage with a cotton ball swabbed with rat, cat or snake odor, the animals avoided the cotton ball, struck a ready-to-run posture, and had elevated levels of stress hormones. The experiment was repeated using mice with a genetic mutation that left them without a functioning VNO. These mice displayed curiosity about the cotton balls but showed little fear.

The research helps scientists better understand animal behavior and may eventually lead to new insights into how sensory information is processed in human brains. The findings appear in the journal Cell.

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Cell phones as sensors

A silicon chip may one day detect dangerous airborne chemicals and alert emergency responders, through the cell phone network, as to the location and extent of the hazard. The sensor, a porous flake of silicon, changes color when it interacts with specific chemicals. By manipulating the shape of the pores, individual spots on the silicon flake can be tuned to respond to specific chemical traits. Potentially, the chips could discriminate among hundreds of different compounds and recognize which might be harmful. Already the chips can distinguish between methyl salicylate, a compound used to simulate the chemical warfare agent mustard gas, and toluene, a common additive in gasoline. Development of the new technology is a collaboration of UCSD scientists and a San Diego-based startup company.

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World’s largest oceanography library now digital

Approximately 100,000 volumes from the Scripps Institution of Oceanography (SIO) Library, the world’s largest oceanography library, have been digitized as part of a partnership between Google, the University of California, and the UCSD libraries. The materials are accessible through the Internet to scholars, students and the public.

In 2008, UCSD became the first Southern California university to partner with Google in its efforts to digitize the holdings of the world’s most prominent libraries. To date, more than 2 million books from UC libraries systemwide have been digitized. News release at


Lynne Friedmann is a science writer based in Solana Beach.