Author: Aida Ombašić

  • How to know if you have low BDNF? What factors are robbing you of it?

    How to know if you have low BDNF? What factors are robbing you of it?

    If you want to optimize your mood and brain function, you need to pay attention to Brain-Derived Neurotrophic Factor (BDNF). It is a protein that helps your brain regrow. You can consider it your brain’s fountain of youth and happiness.

    Unfortunately, the way we eat, live, and use our brains nowadays can lower it, contributing to mental health and cognitive problems.

    In this article, we’ll cover the definition of BDNF, its roles, and the factors that lower it.

    In the next article, Part 2, read about 19 ways to increase BDNF naturally.

    What is BDNF?

    brain

    BDNF is a small protein produced in the brain that stimulates the growth and survival of neurons. It’s also important for the proper development of the nervous system. 

    It stimulates neuroplasticity, which is the brain’s ability to adjust to change. Neuroplasticity is how your brain adapts, masters new skills, and stores information, which are all important for learning and memory.

    What are the roles of BDNF? 

    Promoting neuronal growth and survival

    BDNF stimulates neurons’ growth, generation, and survival. The development and preservation of neuronal networks depend on how many neurotrophins, including BDNF, your brain makes and releases.

    Formation of synapses (synaptogenesis)

    Synapses are the connections between neurons. They control the flow of information between neurons and their target cells. The formation of synapses is a crucial part of memory and learning. BDNF controls the number and arrangement of synapses.

    Mental challenges strengthen the formation and preservation of synapses. These activities also increase BDNF in the brain, stimulating the formation of even more synapses.

    Synaptic plasticity

    Synaptic plasticity means changes in neuronal connections critical for learning and memory.  

    Neurotrophins encourage synaptic plasticity, help preserve cells, and assign cells their functions. BDNF is the most abundant neurotrophin in the brain, suggesting its powerful effects on synapses.  

    Memory

    young asian woman trying to recall what she is readung

    You need synaptic formation and plasticity to form memories and recall the information. 

    Also, your hippocampus is the memory center of your brain. Low BDNF in the hippocampus naturally affects memory and mood. Factors like aging, lack of physical activity, and brain inflammation correlate with low hippocampal BDNF, and thus memory loss.

    Mood

    Low BDNF can allow neurons in the hippocampus to die. In people with depression, these neuronal deaths and shrinkage of the hippocampus correlate with their depression severity. Not surprisingly, improving BDNF levels, such as with exercise, improves mood and relieves depression. 

    Peripheral nerve regeneration after injury

    Although peripheral nerves (nerves located outside the brain and spinal cord) can spontaneously regenerate after injury, their complete recovery is unlikely. BDNF treatments have been successful in treating peripheral nerve regeneration in animal models, and there has been some success in human patients as well.

    What are low BDNF symptoms?

    Depression

    depressed man sitting down with his hands over his head

    If you have been struggling with depression or low mood, you could be experiencing the following changes in BDNF levels in the brain :

    • Lower BDNF in your hippocampus (the brain’s memory center)
    • Lower BDNF in your prefrontal cortex (logical thinking center)
    • Higher BDNF in your nucleus accumbens (part of the reward pathways) 
    • Higher BDNF in your amygdala (the fear memory center). 

    These changes in BDNF levels may explain why you get brain fog, reduced logical reasoning, inability to experience reward or pleasure sensations, and chronic stress responses.

    Dendrites are protrusions from neurons that connect with other neurons. Many depressed people have shortened dendritic trees. Some also have shrunken regions of the brain that are important for cognitive function, possibly due to reduced synapses.

    Poor memory

    A shrinking hippocampus and low BDNF levels explain why old age and reduced physical activity contribute to reduced memory loss

    In a study of nursing home elderly adults, low BDNF levels predicted age-related memory impairment. Therefore, BDNF is a potential biomarker that may help detect age-related memory loss and dementia.

    Brain fog or cognitive dysfunction

    Brain fog and cognition dysfunction refer to decreased cognition, failure to focus or multitask, and forgetfulness. BDNF is crucial for neuroplasticity in the hippocampus, so it is necessary for learning and memory. If you struggle with brain fog, you may benefit from boosting your BDNF levels.

    Now, BDNF isn’t always all good. One of the downsides of BDNF is that it can increase chronic pain sensitization.

    Chronic pain

    men with his hands over his head experiencinf extreme pain

    Chronic pain is pain that lasts longer than six months. The sensory neurons, known as nociceptors, alert us when we encounter painful stimuli. BDNF from sensory neurons can promote pain sensations.

    BDNF is a pain modulator that sensitizes the brain to pain (central sensitization) The sensitization could explain why people feel pain for years even after their injuries have healed. 

    Factors that lower BDNF

    Stress

    Chronic stress reduces BDNF production, especially from your hippocampus. Yet, the BDNF is vital for stress recovery. Therefore, prolonged chronic stress reduces your neuronal plasticity and ability to adapt to change.

    Apart from this, chronic stress increases your risk of developing anxiety, insomnia, and depression.

    On the other hand, acute psychosocial stress raises your BDNF levels.

    student sitting down looking at his laptop worry

    Inflammation

    Inflammation in your body and brain reduces your BDNF levels and neuronal function. Therefore, it can cause brain fog and some neuronal death.

    Poor blood sugar control (dysglycemia)

    Poor blood sugar control and glucose metabolism are linked to low BDNF levels.

    Hyperglycemia (high blood sugar) reduces the lifetime of neurons. It induces their suicide (apoptosis) and kills hippocampal neurons. Both type 1 and type 2 diabetic patients have reduced BDNF levels.

    Social isolation

    Social isolation can lower your BDNF levels and increase cortisol. Both can shrink your hippocampus. The stress levels during social isolation can also lower BDNF levels. All of these can impair learning and memory.  

    Conclusion

    BDNF is your brain’s most abundant neurotrophin that you can target with nootropics and lifestyle. It helps with your brain function, along with memory and mood. 

    Low BDNF can contribute to memory loss, learning problems, brain fog, and mental health issues. Now that you know the symptoms of low BDNF and the lifestyle factors that lower it, you can tell if it’s a problem. 

    Fortunately, there are numerous ways to increase BDNF and boost your cognitive function naturally.

    In part 2 of this 2-part article, we cover 19 ways to increase your BDNF levels.

    References

    1. Bathina S, Das UN. Brain-derived neurotrophic factor and its clinical implications. Arch Med Sci. 2015;11(6):1164-1178.
    2. Puderbaugh M, Emmady. PD. Neuroplasticity. [Updated 2021 Jul 22]. In: StatPearls [Internet].Treasure Island (FL): StatPearls Publishing; Nih.gov. Published 2021. Accessed December 1, 2021. https://www.ncbi.nlm.nih.gov/books/NBK557811/
    3. Angelucci F, Brenè S, Mathé AA. BDNF in schizophrenia, depression and corresponding animal models. Mol Psychiatry. 2005;10(4):345-352.
    4. Caire MJ, Reddy V, M. V. Physiology, Synapse. [Updated 2021 Mar 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Nih.gov. Published 2021. Accessed December 1, 2021. https://www.ncbi.nlm.nih.gov/books/NBK526047/
    5. Jevtovic-Todorovic V. Developmental synaptogenesis and general anesthesia: a kiss of death? Curr Pharm Des. 2012;18(38):6225-6231.
    6. Nelson TJ, Alkon DL. Molecular regulation of synaptogenesis during associative learning and memory. Brain Res. 2015;1621:239-251.
    7. Hua JY, Smith SJ. Neural activity and the dynamics of central nervous system development. Nat Neurosci. 2004;7(4):327-332.
    9. Lu B. BDNF and activity-dependent synaptic modulation. Learn Mem. 2003;10(2):86-98.
    10. Bramham CR, Messaoudi E. BDNF function in adult synaptic plasticity: the synaptic consolidation hypothesis. Prog Neurobiol. 2005;76(2):99-125.
    11. Ramirez A, Arbuckle MR. Synaptic plasticity: The role of learning and unlearning in addiction and beyond. Biol Psychiatry. 2016;80(9):e73-e75.
    12. Gómez-Palacio-Schjetnan A, Escobar ML. Neurotrophins and synaptic plasticity. Curr Top Behav Neurosci. 2013;15:117-136.
    13. Leal G, Bramham CR, Duarte CB. BDNF and hippocampal synaptic plasticity. Vitam Horm. 2017;104:153-195.
    15. Anand KS, Dhikav V. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol. 2012;15(4):239-246.
    16. Martinowich K, Lu B. Interaction between BDNF and serotonin: role in mood disorders. Neuropsychopharmacology. 2008;33(1):73-83.
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    33. Linz R, Puhlmann LMC, Apostolakou F, et al. Acute psychosocial stress increases serum BDNF levels: an antagonistic relation to cortisol but no group differences after mental training. Neuropsychopharmacology. 2019;44(10):1797-1804.
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  • What is the role of BDNF in the brain

    What is the role of BDNF in the brain

    BDNF is a type of neurotrophin. Neurotrophins promote the survival and growth of neurons, a communication cell used to share information within the brain and nervous system . BDNF is particularly essential for cognitive performance, in functions such as memory and learning , and neurotrophins like BDNF are required for proper nervous system development. 

    Though peripheral nerves, or nerves located outside of the brain and spinal cord, can spontaneously regenerate after injury, their complete recovery is unlikely. Because of its role in initiating neuron growth, BDNF has been found to play a role in peripheral nerve regeneration. Studies show that BDNF treatments have been successful in treating peripheral nerve regeneration in animal models, and some success is being seen in human patients.

    What is BDNF?

    BDNF (brain-derived neurotrophic factor) is a small protein produced in the brain that stimulates the growth and survival of neurons .  BDNF assists in neuroplasticity, which is the brain’s ability to adjust to change . Neuroplasticity connects learning and memory—how our brain adapts, masters new abilities, and stores information .

    Important roles of BDNF for cognitive performance and mental health

    Promoting neuronal growth and survival

    BDNF stimulates the growth, generation, and survival of neurons.. The development and preservation of neuronal networks depend on how many neurotrophins, including BDNF, are synthesized and released .

    Formation of synapses (synaptogenesis)

    The places where neurons connect and communicate with each other are known as synapses .  They control the flow of information between neurons and their target cells. Synapses, and their creation, are also the foundation for functions such as memory and learning. Neurotrophins (like BDNF) control the number and arrangement of synapses .

    Neural activities such as mental challenges influence the formation and preservation of synapses, controlling synaptic strength . These activities also increase the creation and secretion of BDNF, stimulating even more synapses .

    Synaptic plasticity

    Changes in neuronal connections, known as synaptic plasticity, are the main factors for learning and memory .

    Neurotrophins encourage synaptic plasticity, as well as help to preserve cells and assign them their function . Of all neurotrophins, BDNF is unique because of its high levels in the brain and its powerful effect on synapses .

    Memory

    Memory helps with learning, memorization, and recalling stored information. The changes in synaptic plasticity affect learning and memory, and BDNF contributes to these processes. The hippocampus is an area of the brain devoted to memory. Aging, lack of physical activity, and low BDNF levels naturally decrease hippocampal activity .

    Mood

    Mood disorders are among the most common and repetitive mental disorders. Poor regulation of synaptic plasticity, along with changes in neurotrophin levels (like BDNF), could lead to mood disorders .

    The hippocampus is also often associated with the development of mood disorders and brain BDNF levels tend to be abnormal in affected individuals .

    Though cognitive performance depends on many factors, BDNF has a significant role. It promotes growth and survival of neurons, and neurons control the flow of information within the central nervous system.

    It’s important to shed light on the complex processes involved in our day-to-day lives, and be aware of their influence on our mental health and most basic functions. Now that you are aware of the importance of BDNF, you may consider what influences the rise or fall of your own brain’s levels.

    References

    1. Cunha C, Brambilla R, Thomas KL. A simple role for BDNF in learning and memory? Front Mol Neurosci. 2010;3:1.
    2. Obata K, Noguchi K. BDNF in sensory neurons and chronic pain. Neurosci Res. 2006;55(1):1–10.
    3. Brem A-K, Ran K, Pascual-Leone A. Learning and memory. Handb Clin Neurol. 2013;116:693–737.
    4. McGregor CE, English AW. The role of BDNF in peripheral nerve regeneration: Activity-dependent treatments and Val66Met. Front Cell Neurosci. 2018;12:522.
    5. Bathina S, Das UN. Brain-derived neurotrophic factor and its clinical implications. Arch Med Sci. 2015;11(6):1164–1178.
    6. Puderbaugh M, Emmady PD. Neuroplasticity. En: StatPearls. StatPearls Publishing; 2021.
    7. Angelucci F, Brenè S, Mathé AA. BDNF in schizophrenia, depression and corresponding animal models. Mol Psychiatry. 2005;10(4):345–352.
    8. Caire MJ, Reddy V, Varacallo M. Physiology, Synapse. En: StatPearls. StatPearls Publishing; 2021.
    9. Jevtovic-Todorovic V. Developmental synaptogenesis and general anesthesia: a kiss of death? Curr Pharm Des. 2012;18(38):6225–6231.
    10. Nelson TJ, Alkon DL. Molecular regulation of synaptogenesis during associative learning and memory. Brain Res. 2015;1621:239–251.
    11. Hua JY, Smith SJ. Neural activity and the dynamics of central nervous system development. Nat Neurosci. 2004;7(4):327–332.
    12. Nakayama K, Kiyosue K, Taguchi T. Diminished neuronal activity increases neuron-neuron connectivity underlying silent synapse formation and the rapid conversion of silent to functional synapses. J Neurosci. 2005;25(16):4040–4051.
    13. Lu B. BDNF and activity-dependent synaptic modulation. Learn Mem. 2003;10(2):86–98.
    14. Bramham CR, Messaoudi E. BDNF function in adult synaptic plasticity: the synaptic consolidation hypothesis. Prog Neurobiol. 2005;76(2):99–125.
    15. Ramirez A, Arbuckle MR. Synaptic plasticity: The role of learning and unlearning in addiction and beyond. Biol Psychiatry. 2016;80(9):e73–e75.
    16. Gómez-Palacio-Schjetnan A, Escobar ML. Neurotrophins and synaptic plasticity. Curr Top Behav Neurosci. 2013;15:117–136.
    17. Leal G, Bramham CR, Duarte CB. BDNF and hippocampal synaptic plasticity. Vitam Horm. 2017;104:153–195.
    18. Brigadski T, Leßmann V. BDNF: a regulator of learning and memory processes with clinical potential. eNeuroforum. 2014;5(1):1–11.
    19. Mizoguchi Y, Yao H, Imamura Y, Hashimoto M, Monji A. Lower brain-derived neurotrophic factor levels are associated with age-related memory impairment in community-dwelling older adults: the Sefuri study. Sci Rep. 2020;10(1):16442.
    20. Anand KS, Dhikav V. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol. 2012;15(4):239–246.
    21. Hashimoto K, Shimizu E, Iyo M. Critical role of brain-derived neurotrophic factor in mood disorders. Brain Res Brain Res Rev. 2004;45(2):104–114.
    22. Shih-Jen T, Chen-Jee H. Effect of brain-derived neurotrophic factor (BDNF) gene variants on the therapeutic response and the risk for mood disorders. Current Pharmacogenomics and Personalized Medicine. 2008;6(2):126–133.
    23. Martinowich K, Lu B. Interaction between BDNF and serotonin: role in mood disorders. Neuropsychopharmacology. 2008;33(1):73–83.