economics Nature Is Weird

A protein we know for building brain connections has a secret second job as a cellular sculptor.

April 3, 2026

Original Paper

Extracellular Neuroligin–icam5 Coupling Drives Dendritic Growth via Actin Remodeling

SSRN · 6506752

The Takeaway

Textbooks teach that 'neuroligins' only help build the synapses where brain cells talk to each other. This study reveals they also physically reshape the 'branches' of the neuron through a completely separate pathway that has nothing to do with communication.

From the abstract

Neuroligins (NLGNs) organize neuronal connectivity by engaging a diverse set of interaction partners, yet how extracellular recognition couples to intracellular growth programs remains unclear. Using affinity proteomics, we identify intercellular adhesion molecule-5 (ICAM5), a cell-surface protein localized to dendritic filopodia, as a novel neuroligin interactor. Surface plasmon resonance and cell-based assays demonstrate direct binding between the ICAM5 and NLGN3 extracellular domains and reve