Neurexins and neuroligins are synaptic cell-adhesion molecules that play a crucial role in connecting pre- and postsynaptic neurons, mediating trans-synaptic signaling, and shaping neural network properties. Alterations in these genes have been implicated in autism and other cognitive diseases, linking synaptic cell adhesion to cognitive disorders. Neurexins are type 1 membrane proteins with α- and β-isoforms, while neuroligins are simpler type-I membrane proteins. They form a trans-synaptic complex that recruits intracellular proteins, particularly PDZ-domain proteins, to mediate synaptic function. Mutations in neurexin and neuroligin genes are associated with autism, Tourette syndrome, mental retardation, and schizophrenia, suggesting their importance in cognitive diseases. The precise mechanisms by which neurexins and neuroligins function remain largely unknown, but they likely activate synaptic function and specify synaptic properties through interactions with other proteins. The involvement of these molecules in cognitive diseases highlights the need for further research to understand their role in synaptic transmission and neural network function.Neurexins and neuroligins are synaptic cell-adhesion molecules that play a crucial role in connecting pre- and postsynaptic neurons, mediating trans-synaptic signaling, and shaping neural network properties. Alterations in these genes have been implicated in autism and other cognitive diseases, linking synaptic cell adhesion to cognitive disorders. Neurexins are type 1 membrane proteins with α- and β-isoforms, while neuroligins are simpler type-I membrane proteins. They form a trans-synaptic complex that recruits intracellular proteins, particularly PDZ-domain proteins, to mediate synaptic function. Mutations in neurexin and neuroligin genes are associated with autism, Tourette syndrome, mental retardation, and schizophrenia, suggesting their importance in cognitive diseases. The precise mechanisms by which neurexins and neuroligins function remain largely unknown, but they likely activate synaptic function and specify synaptic properties through interactions with other proteins. The involvement of these molecules in cognitive diseases highlights the need for further research to understand their role in synaptic transmission and neural network function.