TALEN (Left:ttcagAATGATTCATGGG, Right:ACGCACTCTTCAAAGCTA)targeting the exon4 of hyperpolarization-activated cyclic nucleotide-gated 1 channel (Hcn1) gene was designed and mRNA coding these TALEN was microinjected into F344/NSlc embyo. A 13-bp deletion in the exon4 of Hcn1 gene: as a result of frameshift mutation, stop codon is produced. Decreased expression levels of Hcn1 gene and HCN1 protein.