BAR-domain proteins deform the dendritic membrane to initiate spine formation.

Actin polymerization and clutch coupling produce force to extend dendritic filopodia.

Cytoskeletons, CAMs, and the ECM provide mechanical support for spine structure.

Tunable clutch coupling mediates generation of force for spine structural plasticity.

Force from expanding spines affects presynaptic neurotransmitter release.

Dendritic spines are small protrusions arising from dendrites and constitute the major compartment of excitatory post-synapses. They change in number, shape, and size throughout life; these changes are thought to be associated with formation and reorganization of neuronal networks underlying learning and memory. As spines in the brain are surrounded by the microenvironment including neighboring cells and the extracellular matrix, their protrusion requires generation of force to push against these structures. In turn, neighboring cells receive force from protruding spines. Recent studies have identified BAR-domain proteins as being involved in membrane deformation to initiate spine formation. In addition, forces for dendritic filopodium extension and activity-induced spine expansion are generated through cooperation between actin polymerization and clutch coupling. On the other hand, force from expanding spines affects neurotransmitter release from presynaptic terminals. Here, we review recent advances in our understanding of the physical aspects of synapse formation and plasticity, mainly focusing on spine dynamics.

Synaptic plasticity

BAR-domain protein

Shootin1

Cadherin

L1

Laminin

cell adhesion molecule

Ca2+/calumodulin-dependent protein kinase

Fes-CIP4 homology BAR

guanin nucleotide exchange factor

inverse-Fes-CIP4 homology BAR

N-terminal amphipathic helix-containing BAR

NMDA-type glutamate receptor

soluble N-ethylmaleimide-sensitive factor attachment protein receptor

Slit-Robo GTPase activating protein3

WAVE-associated Rac-GAP protein

© 2022 The Author(s). Published by Elsevier Ltd.