Fig. 3. Differential distribution of mHCN1, mHCN2, and mHCN4 in the mouse cerebral and hippocampal cortex. A,Coronal section (bregma, +0.74) showing mHCN1 labeling in the motor cortex. B, Coronal section (bregma, −2.06) showing mHCN1 labeling in the hippocampus. C, mHCN2 labeling in the motor cortex. D, mHCN2 labeling in the hippocampus, lateral habenula, and dorsal lateral geniculate nucleus.E, mHCN4 labeling is absent in the motor cortex.F, mHCN4 labeling in the hippocampus, medial and lateral habenula, and dorsal lateral geniculate nucleus. ec, External capusle; mh, medial habenula;lh, lateral habenula; dlg, dorsal lateral geniculate nucleus; DG, dentate gyrus;CA1, CA3,cornus ammonis fields CA1 and CA3. Scale bars, 500 μm.