Fig 1: Novel marker genes for excitatory neuronal cell types in CN.(A) Left: UMAP visualization of all neurons in the Phgdh+ cluster (n = 88) and all Patch-seq cells assigned to octopus cells positioned on the UMAP space. Middle and Right: UMAP visualization of the normalized expression of discriminatory markers for octopus cell cluster (Phgdh in the middle, Dkk3 on the left). (B) FISH co-staining for Slc17a6 and Phgdh (left), or Slc17a6 and Dkk3 (right) in sagittal sections of the CN. D, dorsal; V, ventral; A, anterior; M, posterior. Inset pie charts show the percentage of double-labeled cells (Phgdh+/Slc17a6+ or Dkk3+/Slc17a6+) in single-labeled cells (Phgdh+ or Dkk3+). Yellow lines along FISH images show the density of double-labeled neurons (yellow) along two axis of the CN. (C) Top left: a diagram showing patch recording and labeling with biocytin for octopus cells. Top middle: example membrane responses of an octopus cell to current steps. Scale bar, vertical 25 mV for the potential, 10 nA for the injected currents. Top right: the proportion of octopus cells immunopositive for Phgdh. Bottom: one example octopus cell filled with biocytin (green) shows positive signals for Phgdh (red). (D) Left: UMAP visualization of all neurons in the Tnnt1+ cluster (n = 274) and all Patch-seq cells assigned to fusiform cells positioned on the UMAP space. Middle and Right: UMAP visualization of the normalized expression of discriminatory markers for fusiform cells (Necab2 on the middle, Ppfibp1 on the left). (E) FISH co-staining for Slc17a6 and Necab2 (left), or Slc17a6 and Ppfibp1 (right) in CN sagittal sections. Inset pie charts show the proportion of double-labeled cells (Necab2+/Slc17a6+ or Ppfibp1+/Slc17a6+) in single-labeled cells (Necab2+ or Ppfibp1+). Yellow lines along FISH images show the density of double-labeled neurons (yellow) along two axis of the CN. (F) Top left: a diagram showing patch recording and labeling with biocytin for fusiform cells. Top middle: example membrane responses of a fusiform cell to current steps. Scale bar, vertical 25 mV for the potential, 1 nA for the injected currents. Top right: The proportion of fusiform cells immunopositive for Necab2. Bottom: One example fusiform neuron filled with biocytin (green) shows positive signals for Necab2 (red).