Astrocytes Take Center Stage in Salt Sensing

study is its methodological simplicity. Lesion studies are often thought not to be informative about processing mechanisms; in other words they are often thought to answer the question ‘‘What does this area do?’’ rather than the (harder) question of ‘‘How does it do it?’’ But in using a wellstudied behavioral paradigm for testing discrimination learning in rodents and straightforward neurotoxic lesion methods, the authors have tested (and validated) a counterintuitive hypothesis formulated on the basis of neurophysiological observations in the same behavioral setting. This validation is very strong because the lesion method establishes causality, rather than simply correlation. This discovery did not require elaborate neurobiological techniques, and recalls the thoughts of von Bonin (1960) on then-new neurophysiological methods: ‘‘Much of this is all to the good, but the older approach should not be completely forgotten when one gets dazzled by the modern treatment of the subject.’’ Stalnaker et al. have shown that the lesion method can still dazzle, and has much to contribute in terms of elucidating the neural mechanisms of cognition.