Mediates selective neuronal growth and axon targeting. Contributes to the guidance of developing axons and remodeling of mature circuits in the limbic system. Essential for normal growth of the hippocampal mossy fiber projection. Expressed mostly by neurons comprising limbic-associated cortical and subcortical regions that function in cognition, emotion, memory, and learning. First detected at E15-16, at stage E20 it is detected in presumptive cortex, medial limbic areas of the thalamus and hypothalamus. In the adult, it is found in hypothalamus, perirhinal cortex, amygdala and medial thalamic region. GPI-anchored form. Belongs to the immunoglobulin superfamily. IgLON family.