To this end, they tested the effects of nicotine on genetically altered mice that lacked certain portions of the nicotine receptor. Their experiments showed that mice in which the beta 2 subunit was defective did not self-administer nicotine as normal mice do. Furthermore, when the beta 2-defective mice were injected with nicotine, they, unlike normal mice, showed no increase in dopamine secretion. These results suggest that the beta 2 subunit of the nicotine receptor is the molecular key to the development of nicotine addiction. Let us hope that it is also the key to more effective treatments.
Right whales are stocky, slow-swimming whales that carry a rich supply of oil.
Right whales were not given international protection until 1937, and violations of the ban were common until the 1960s. Today, less than 300 northern right whales exist and it is estimated that the population of southern right whales constitutes only about three to five percent of the pre-whaling original. Until recently, scientists believed that certain populations of the southern right whale, including the population that migrated up and down the coast of New Zealand, had disappeared entirely. Now, genetic analysis of whales in a whale sanctuary off the Auckland Islands suggests that a tiny fraction of this population may have survived. The Auckland Island whales were thought to have to be members of the Australian population, but it turns out their DNA is too dissimilar for this to be the case.