Intracellular Transport and Cytoskeleton of Neurons

Structure of Neuronal Cytoskeleton

Neurons are supported by four compartmentalized components that function together to send and receive the information, namely the cell body (soma), axon, dendrites and axon terminals. Moreover, there are a lot of subcellular structures in the neurons. The neuronal cytoskeleton mainly comprises neurofilaments, microtubules, actin filaments. Three classes of filaments supporting the dynamic function of the neuronal cytoskeleton have been identified:

Fig.1 Three classes of filaments.

All of these structures are key to maintain the basic framework and functions of neurons. The cytoskeletal proteins of neurons have important functions to guarantee the transmission of electrical/chemical signals between different neurons.

Fig.2 Main elements of the neuronal cytoskeleton. (Muñoz-Lasso, 2020)

Functions of Neuronal Cytoskeleton

The three elements of the neuronal cytoskeleton work together to guarantee the proper formation and essential function of the nervous system (NS). Changes in the expression, dynamics, and stability of cytoskeletal proteins may lead to several neurological disorders.

• The neuronal cytoskeleton participates in the growth and guidance of axons during embryonic development;
• Neurons utilize the cytoskeleton for maintaining neuronal homeostasis and neuronal plasticity during adult life;
• A specific set of cytoskeletal proteins are needed to ensure the axonal regeneration of peripheral nerves after damage.

Intracellular Transport in Neurons

Typically, neurons receive signals via the dendrites and send out signals down the axon; therefore, neuronal cells have to transport materials and signals from one side to the other for their correct functionality. In the axon and dendrites, transport occurs bidirectionally. Axonal transport is the main and the most important process to deliver a wide range of proteins and specialized structures up and down axons. Driven by molecular motors distributing along axonal microtubules, it is key for the distribution and transport of vesicles and signaling molecules along the axon to control polarization, axon elongation, and synapse function.

• Axonal transport is dependent on three key components: microtubules, anterograde transport machinery and retrograde transport machinery.
• Axonal transport can occur in two directions: anterograde transport (from the cell body toward the axon tip), and retrograde transport (from the axon tip back toward the cell body).
• Many substances are simultaneously transported along microtubules found within axons.

Fig.3 Axonal transport in the neurons. (Sleigh, 2020)

The cytoskeleton of neurons represents the basic matrix along which proteins, mRNAs, or signals are transported to their final destinations. Neuronal cytoskeleton and transport research is becoming an exciting frontier of neuroscience. As a world-leading services provider in the field of neuroscience, Creative Biolabs has developed a full line of high-quality neuroscience products to promote your research process, including but not limited to antibodies, proteins, cell lines, as well as customized development services. If you are interested in our services and products, please do not hesitate to contact us for more detailed information.

References

1. Muñoz-Lasso, D. C.; et al. Much more than a scaffold: cytoskeletal proteins in neurological disorders. Cells. 2020, 9(2): 358.
2. Sleigh, J. N. Axonal Transport: The Delivery System Keeping Nerve Cells Alive. Frontiers for Young Minds. 2020, 8.