Mechanics-mediated Neural Plasticity
Neural plasticity is the brain’s capacity to reconfigure synaptic connections in response to activity and experience. At the cellular level, this process is governed by the nanoscale geometry of the synaptic cleft, where neurotransmitters diffuse and bind to receptors. Small changes in cleft width or shape can significantly alter the probability of receptor opening, thereby tuning the strength of synaptic transmission. Plasticity emerges from this dynamic interplay: repeated activity reshapes receptor distributions and cleft geometry, reinforcing or weakening connections. These mechanisms operate on timescales ranging from milliseconds for receptor activation to minutes and hours for structural remodeling. Understanding this biophysical regulation of neurotransmission sheds light on how the brain encodes learning and memory, and how perturbations can impair or restore neural function.
Selected papers
B Kaytanli, M Bacca (2025). Morphological trapping of neurotransmitters in synaptic clefts: A new dimension in neural plasticity. Biophysical Journal 124, 1-17
Mechanics guides Infection and Replication in Enveloped Viruses
Virus infection and replication occur via the deflection of a cell membrane promoted by the affinity between transmembrane proteins. These are macromolecules that diffuse across the membranal fluid mosaic to accommodate wrapping and unwrapping. Virus replication involves wrapping the membrane around the nucleocapsid followed by the expulsion (exocytosis or budding) of the virus progeny. This process takes ~ 10 minutes. Virus infection, taking ~ 1 min, involves wrapping the cell membrane around the virus particle (endocytosis), or unwrapping the virus membrane to fuse with that of the cell (membrane fusion). The mechanism of virus replication defines the tightest constraints to the size distribution of a virus population. Also, the size of molecular antibodies can help prevent and/or regulate the cellular uptake of nanoparticles and viruses.
Selected papers
*M Bacca (2022). Mechanics of diffusion-mediated budding and implications for virus replication and infection. Journal of the Royal Society Interface 19, 20220525
D Agostinelli, GJ Elfring, M Bacca (2022). The morphological role of ligand inhibitors in blocking receptor-and clathrin-mediated endocytosis. Soft Matter 18 (18), 3531-3545
Covers
*JRSI December 2022