Rationale: Fig. 2c, The Thy1 promoter-driven LGI1-FH protein was functionally secreted and bound to neurons that express ADAM22. LGI1 is a secreted proteins that binds to the postsynaptic protein ADAM22 Literal "the LGI1 point mutation (E383A) observed in patients with ADPEAF prevented its neuronal secretion and binding to ADAM22 in hippocampal neurons, whereas secreted wild-type LGI1 bound to ADAM22 at dendritic spines (Fig. 2C)." Fig. 5e,f, Immunofluorescence labeling of LGI1 shows that LGI1 with PSD-95 at the molecular layer of the hippocampal regions. Immuno-EM of hippocampal dentate gyrus shows that LGI1 localizes at the synaptic site. Literal "On immunofluorescent microscopic examination, LGI1 was detected as tiny puncta at the molecular layers of the hippocampal regions (Fig. 5E). LGI1 was often apposed or colocalized with PSD-95. Furthermore, immunoelectron microscopic analysis showed that gold particles for LGI1 were often detected at or around the synaptic cleft in the hippocampal dentate gyrus region (Fig. 5F, arrowheads)" Fig. S3a, LGI1, is enriched at both both in Triton X-100–soluble presynaptic and insoluble PSD fractions Literal "We next asked whether LGI1 controls subcellular distributions of ADAM22, ADAM23, and Kv1. LGI1, ADAM22, and ADAM23 similarly distributed both presynaptically and postsynaptically (Fig. S3A).". Experimental description: Biochemical, immunofluorescent and immuno-EM experiments were done on mouse. Literal from Supplementary M&M "Subcellular Fractionation. Brains from littermate mice (P16) were homogenized in buffer C." "Immunohistochemistry. Littermate mice (P17–19) were anesthetized by pentobarbital" "Postembedding Immunoelectron Microscopy. Mice were anesthetized and perfused"