Axonal lipid membrane

The axonal lipid membrane, or axolemma, is a specialized phospholipid bilayer that surrounds the axon and is essential for maintaining the electrochemical gradients necessary for nerve impulse conduction (PubMed: 27163172). Upon nerve transection, the physical disruption of this membrane leads to an immediate influx of extracellular calcium, triggering a cascade of events that results in Wallerian degeneration of the distal nerve segment (PubMed: 22451475). In the context of regenerative medicine, the axonal lipid membrane at the site of injury serves as a therapeutic target for membrane fusogens such as polyethylene glycol (PEG) (PubMed: 26858916). These agents facilitate the rapid reconnection of the severed axonal ends by promoting the fusion of the lipid bilayers, which can restore immediate physiological continuity and bypass the slow process of natural axonal regeneration (PubMed: 27163172). This approach, often referred to as PEG-fusion, aims to prevent the loss of the distal axon and its associated motor or sensory targets (PubMed: 11934344). Beyond PEG, other surfactants like poloxamers are also being explored for their ability to seal damaged membranes and prevent cell death (PubMed: 15183872). The success of targeting the axonal membrane depends heavily on the timing of application and the precise alignment of the severed nerve ends (PubMed: 26858916). This therapeutic strategy is primarily investigated for the treatment of acute peripheral nerve injuries and spinal cord trauma (PubMed: 26858916).

Other names

AxolemmaAxonal membraneNerve cell membrane

Membrane fusogens like polyethylene glycol (PEG) act by dehydrating the polar headgroups of the lipid bilayer at the site of transection, reducing the hydration barrier and allowing the disrupted axonal membranes to merge and fuse, thereby restoring axonal continuity and preventing Wallerian degeneration (PubMed: 27163172, PubMed: 26858916).