This study describes a way to establish the molecular profiles of neurons that respond to a particular stimulus. The authors found that, in mice, stimulus-induced neural activity often leads to a rise in the level of phosphorylated ribosomal protein S6 (pS6). Using specific anti-pS6 antibodies and mouse brain homogenates, they specifically immunoprecipitated ribosomes and their associated mRNAs from neurons in which S6 phosphorylation had been induced. This method might help to reveal the neural mechanisms that underlie various behaviours. For example, through pS6 capture, the authors showed that fasting in mice is linked to galanin neuron activity.