axolemma

The axolemma is the cell membrane surrounding an axon.

The signaling pathways leading to axolemma degeneration are currently unknown.

Degeneration follows with swelling of the axolemma, and eventually leads to bead like formation.

Mauthner's sheath: The plasma membrane of an axon; also known as an axolemma.

An unmyelinated axolemma has a high capacitance which imposes a restraint on the conduction speed.

The presynaptic blockade was due to the phospholipase, a component of the textilotoxin acting on the axolemma.

Granular disintegration of the axonal cytoskeleton and inner organelles occurs after axolemma degradation.

It also opens sodium channels in the axolemma, which causes voltage-gated calcium channels to open and Ca to flow into the cell.

Later, several autopsies confirmed the focus of the immune attack was at the motor axolemma especially around the nodes of Ranvier.

These cases showed deposition of antibody and complement along the motor axolemma and associated macrophage infiltration.

In the node alone, the axolemma is contacted by several Schwann microvilli and contains a dense cytoskeletal undercoating.

Hamilton et al. (1980) showed that the crude venom produced "coated omega figures" in the axolemma of the rat nerve terminals.

If the axolemma is damaged, it becomes unable to perform its vital role of maintaining the concentration gradient of ions inside and outside of the cell.

At the paranodal regions, the paranodal cytoplasm loops contact thickenings of the axolemma to form septate -like junctions.

In the PNS, specialized microvilli project from the outer collar of Schwann cells and come very close to nodal axolemma of large fibers.

In the internodal region, the Schwann cell has an outer collar of cytoplasm, a compact myelin sheath, and inner collar of cytoplasm, and the axolemma.

While sometimes only the cytoskeleton is disturbed, frequently disruption of the axolemma occurs as well, causing the influx of Ca into the cell and unleashing a variety of degrading processes.

Potassium channels are essentially absent in the nodal axolemma, whereas they are highly concentrated in the paranodal axolemma and Schwann cell membranes at the node.

The axolemma disintegrates, myelin breaks down and begins to detach from cells in an anterograde direction (from the body of the cell toward the end of the axon), and nearby cells begin phagocytic activity, engulfing debris.

If the axoplasm contains many molecules that are not electrically conductive, it will slow the travel of the potential because it will cause more ions to flow across the axolemma (the axon's membrane) than through the axoplasm.

Although freeze fracture studies have revealed that the nodal axolemma in both the CNS and PNS is enriched in intra-membranous particles (IMPs) compared to the internode, there are some structural differences reflecting their cellular constituents.

Anti-GD1a antibodies were highly associated acute motor axonal neuropathy while high titers of anti-GM1 were more frequent indicating that GD1a possibly targets the axolemma and nodes of Ranvier most of the Ab+ patients had C. jejuni infections.

The myelinating glial cells, oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS), are wrapped around the axon, leaving the axolemma relatively uncovered at regularly spaced nodes of Ranvier.

The inner mesaxon (Terminologia histologica: Mesaxon internum) is the connection between the myelin sheath and the inner part of the cell membrane of the Schwann cell which is directly opposite the axolemma, i.e. the cell membrane of the nerve fibre ensheathed by the Schwann cell.