Engineering memory with an extrinsically disordered kinase

Abstract

Synaptic plasticity plays a crucial role in memory formation by regulating the communication between neurons. Although actin polymerization has been linked to synaptic plasticity and dendritic spine stability, the causal link between actin polymerization and memory encoding has not been identified yet. It is not clear whether actin polymerization and structural changes in dendritic spines are a driver or a consequence of learning and memory. Using an extrinsically disordered form of the protein kinase LIMK1, which rapidly and precisely acts on ADF/cofilin, a direct modifier of actin, we induced long-term enlargement of dendritic spines and enhancement of synaptic transmission in the hippocampus on command. The activation of extrinsically disordered LIMK1 in vivo improved memory encoding and slowed cognitive decline in aged mice exhibiting reduced cofilin phosphorylation. The engineered memory by an extrinsically disordered LIMK1 supports a direct causal link between actin-mediated synaptic transmission and memory.

The gut-brain vagal axis scales hippocampal memory processes and plasticity

“…While the causative role of spines’ structural remodeling in learning and memory is still debated, a strong positive correlation has been observed between spines’ dynamics ( i.e. formation, elimination, retraction, stabilization, enlargement) and learning and memory functions (Berry and Nedivi, 2017; Ripoli et al, 2023; Segal, 2017), especially in the hippocampus. Although we cannot provide evidence on whether SDV-induced reduction of mushroom, thin and stubby spines is the result of increased elimination and/or decreased formation/maturation of spines, it is reasonable to hypothesize that a dampened number of dendritic spines following SDV may contribute in shifting and scaling synaptic plasticities (LTD, LTP and PPF).…”