A decade of progress in understanding LRRTM and Slitrk synaptic cell-adhesion molecules

For over a decade, synaptic cell-adhesion molecules (CAMs) have been recognized as fundamental determinants of neural circuit specificity and diversity. Among the CAMs, leucine-rich repeat-containing transmembrane proteins have been established as crucial regulators of synaptic properties across diverse cell types and brain regions. This minireview focuses on two families of leucine-rich repeat-containing CAMs: leucine-rich repeat transmembrane proteins and the Slit and Trk-like family. We provide a comprehensive synthesis of significant findings on leucine-rich repeat transmembrane proteins and Slit and Trk-like family since their initial characterization more than 15 years ago. Furthermore, we outline key unresolved questions to stimulate future studies on their functional mechanisms in neural circuit assembly and their pathophysiological roles in various neurological disorders.