Laurie's Blogs.

Have I got you curious?  Fantastic!  Then hang on for the lesson!

Wikipedia describes it as follows:

“Brain-derived neurotrophic factor (BDNF), or abrineurin, is a protein that, in humans, is encoded by the BDNF gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the canonical nerve growth factor. Neurotrophic factors are found in the brain and the periphery. BDNF was first isolated from a pig brain in 1982 by Yves-Alain Barde and Hans Thoenen.”¹

What does BDNF do?

BDNF has an effect on the central and peripheral nervous systems.  It helps support the survival of existing neurons, and encourages growth and differentiation of new neurons and synapses.

It can do the following (and more):

• BDNF can help with synaptic transmission (i.e. communication for neuron to neuron)
• BDNF plays a significant role in neurogenesis (the creation and development of new neurons)
• Cognitive function is enhances with environmental enrichment.  The mechanism by which this works appears to be via BDNF expression in such environments.

What causes the creation of BDNF?

“One of the most significant effects of exercise on the brain is increased synthesis and expression of BDNF.”²

Exercise-induced increases in BDNF signaling are associated with beneficial epigenetic changes, improved cognitive function, improved mood, and improved memory.  Furthermore, research has provided a great deal of support for the role of BDNF in hippocampal neurogenesis, synaptic plasticity, and neural repair.²

Why do you care about this clinically?

It has been shown in spinal-cord-injured rats, that an infusion of BDNF to the spinal cord resulted in acute activation of air-stepping and a slight improvement in gait scores.³  Infusion of BDNF to the spinal cord (injured rat study again), also suppresses delayed apoptosis (i.e. cell death) of oligodendrocytes.⁴

A 2016 review paper looked at exercise training for the promotion of spinal cord injury recovery and determined that exercise can induce the neurotrophic factor BNDF, insulin-like growth factor I (IGF-I), and vascular endothelial growth factor (VEGF), to promote spinal oligodendrocyte regeneration.⁵

And another rat study noted that treadmill training of spinal cord injured subject improved BDNF expressions in the motor cortex as well as other neuroplasticity markers.  The treadmill trained group saw improvements in locomotor recovery as well.⁶

Additionally, another review paper noted that, “Sustained exercise, particularly if applied at moderate intensity and early after injury, exerts anti-inflammatory and pro-regenerative effects, and may boost cognitive and motor functions in aging and neurological disorders.”⁷

There are more studies where these came from.  The take away?  Spinal cord injured patients need to MOVE in order to heal.  Treadmill training is a great way to accomplish this goal.  And, as I am prone to saying, “There is no crate-rest fairy!”  Get these dogs moving (safely of course) for best outcomes!

On that note, keep being awesome this week!

Cheers, Laurie

References:

1. Wikipedia.  Brain-derived neurotrophic factor.  https://en.wikipedia.org/wiki/Brain-derived_neurotrophic_factor  Accessed Nov 13, 2022.
2. Wikipedia.  Neurobiological effects of physical exercise. https://en.wikipedia.org/wiki/Neurobiological_effects_of_physical_exercise#BDNF_signaling Accessed Nov 13,2022.
3. Jakeman LB, Wei P, Guan Z, Stokes BT. Brain-derived neurotrophic factor stimulates hindlimb stepping and sprouting of cholinergic fibers after spinal cord injury. Exp Neurol. 1998 Nov;154(1):170-84. 
4. Koda M, Murakami M, Ino H, Yoshinaga K, Ikeda O, Hashimoto M, Yamazaki M, Nakayama C, Moriya H. Brain-derived neurotrophic factor suppresses delayed apoptosis of oligodendrocytes after spinal cord injury in rats. J Neurotrauma. 2002 Jun;19(6):777-85. 
5. Fu J, Wang H, Deng L, Li J. Exercise Training Promotes Functional Recovery after Spinal Cord Injury. Neural Plast. 2016;2016:4039580. 
6. Ilha J, Meireles A, de Freitas GR, do Espírito Santo CC, Machado-Pereira NAMM, Swarowsky A, Santos ARS. Overground gait training promotes functional recovery and cortical neuroplasticity in an incomplete spinal cord injury model. Life Sci. 2019 Sep 1;232:116627. 
7. Cobianchi S, Arbat-Plana A, Lopez-Alvarez VM, Navarro X. Neuroprotective Effects of Exercise Treatments After Injury: The Dual Role of Neurotrophic Factors. Curr Neuropharmacol. 2017;15(4):495-518.