Annual Meeting Logo

Back some time ago I challenged readers of this blog to identify what it is that the logo of the SfN meeting represent.


THE ANSWER:  A Tyrosine Kinase Receptor (TRK)


Some members of this diverse family of receptors mediating the response to neurotrophic factors -  molecules that play important roles in determining the development and survival of neurons. The effects of neurotophins are chiefly mediated by TRK-A, TRK-B, and TRK-C receptors.


For example, Neuronal Growth Factor (NGF) is a neurotrophic factor that plays a role in promoting the survival of neurons through the TRK-A receptor.  Interestingly,  NGF can also bind p75 receptors  - a member of the Tumor Necrosis Factor (TNF) family of receptors.

Examine the SfN logo again.  One of the interesting aspects of the TRK family or receptors is that when their ligand (e.g., NGF) is bound to the receptor, they form functional dimers - two paired receptor components.  The function of the activated dimer-receptor complex  is determined by the pair of components that form the dimer.  There can be functional homo-dimers as well as functional hetero-dimers (two similar components or two different components, respectively). An example is p75/TRK-A dimers which are functionally more responsive to NGF than TRK-A homo-dimers (Baker, 2004), .

Another neurotophin, Brain Derived Neurotrophic Factor (BDNF), exerts its influence via the TRK-B receptors.   Chronic stress decreases BDNF production which has been implicated in several neurodegenerative disorders and some psychiatric conditions that are characterized by regionally selective neuronal degeneration such as chronic depression and Post Traumatic Stress Disorder (e.g., Dell'Osso, L. et al, 2009) .

 


For more on BDNF and TRK receptors and depression, you can peruse another blogger's post by following this link, or you can read the review by Nobel et al (2011) - Caution:  the content is comprehensive and advanced).

Cited Sources

• Baker, P.A. (2004).  p75NTR is positively promiscuous: Novel partners and new insights. Neuron, 42 (4), 529-533. doi:10.1016/j.neuron.2004.04.001
• Dell'Osso, L. et al. (2009). Brain-derived neurotrophic factor plasma levels in patients suffering from post-traumatic stress disorder. Progress in Neuro-Psychopharmacology & Biological Psychiatry, 33, 899-902. doi:10.1016/j.pnpbp.2009.04.018
• Nobel, E.E. et al. (2011). The lighter side of BDNF. American Journal of Physiology: Regulatory and Integrative Comparative Physiology, 300 (5), R1053-R1069. doi: 10.1152/ajpregu.00776.2010