This dark-field image shows a section of mouse hippocampus in which BiP mRNA was detected using 33P-labeled oligonucleotide probes and signal visualized as accumulation of bright silver grains. Very strong signal is evident over the pyramidal and granule cell layers as well as over several scattered cells in the other hippocampal layers. For more information, see the article by Costas-Insua et al. (pages 7924–7941). Cover Image: M. Teresa Vilaró.