Knockout rats carry a 291 bp deletion, including exon-6 of Gad1 gene using the CRISPR/Cas9. Glutamate decarboxylase (GAD; there are two isoforms, GAD65 and GAD67) is an enzyme that synthesizes the neurotransmitter GABA. In this strain, the Gad1 gene encoding GAD67 was knocked out. In homozygous rats, low body weight at 3 weeks and impaired spatial learning memory were observed. Some homozygous rats die as juveniles. This strain is maintained in heterozygotes.