Supplementary Figure 1: Histology for MEC-implanted mice.
From: Grid scale drives the scale and long-term stability of place maps
Histology for MEC-implanted mice. Injected wildtype mice (iWT) shown at top, injected floxed HCN1 (iCre-KO) mice shown at bottom. The mouse ID is shown above each section. For each mouse, left columns: Nissl stained sagittal sections. Black arrow marks the deepest tetrode location. An area was considered infected if the mean fluorescent intensity was greater than two standard deviations (SD) above the mean background intensity. The approximate area of virus infection in MEC is outlined in green. This area was estimated from multiple GFP images covering ± 160 µm from the slice containing the final tetrode location. In the same slices, any GFP detected in the hippocampus was additionally quantified using Image-Pro Plus. A small amount of GFP expression was detected in CA1 of three iWT (mice #34, #48, #79) and one iCre-KO mouse (mice #18) (portion of CA1 infected: iWT = 2–5%, iCre-KO = 3%). Three iWT mice (mice #34, #47, #81) and two iCre-KO (mice #70, #82) mice had minor infection of the dentate gyrus, where HCN1 is only lowly expressed1,2 (portion of dentate gyrus infected: iWT = 12–30%, iCre-KO= 6–11%). For each mouse, right columns: Close up of GFP expression in the area near the final tetrode location (indicated by the white arrowheads).
1. Seo, H., Seol, M.J. & Lee, K. Differential expression of hyperpolarization-activated cyclic nucleotide-gated channel subunits during hippocampal development in the mouse. Molecular brain 8, 13 (2015).
2. Santoro, B., et al. Molecular and functional heterogeneity of hyperpolarization-activated pacemaker channels in the mouse CNS. J Neurosci 20, 5264–5275 (2000).
