Neuron, volume 57 Supplemental Data Ivy Cells: A Population of Nitric-Oxide-Producing, Slow-Spiking GABAergic Neurons and Their Involvement in Hippocampal Network Activity

Figure S1. Molecular expression profile of putative Ivy cells. Fluorescent micrographs show putative Ivy cells (arrows) in and around stratum pyramidale identified by the co-localization of nNOS, NPY and in the top panel the α1 subunit of the GABAA receptor. Putative Ivy cells are immunonegative for the Ca2+-binding proteins PV, CB, CR, or the neuropeptide somatostatin (SM). On the other hand, a large fraction of putative Ivy cells showed somatic labeling for α-actinin-2. Scale bars 20 μm. Figure S2. An Ivy cell with a large axonal field spanning three layers recorded in vivo. (A) Schematic sagittal view and rostro-caudal extent of the axonal and dendritic arborizations of cell T134a. (B) Fluorescence micrographs of the soma cut in half during sectioning. The recorded cell is immunopositive for nNOS and GABAAR-α1 in one half of the soma, and NPY in the other half. For examples of the firing patterns of this cell, see Supplementary Figure 3. (C) Reconstruction of the soma and dendrites (orange) are shown from three sections, the axon (yellow) is shown only from four 70-μm-thick sections for clarity. Note the very dense axon in both stratum oriens and proximal radiatum. A pyramidal cell (blue, T57d) recorded and labeled in another animal, is added for illustrating spatial relationships. Scale bars: (B) 10 μm; (C) 100 μm