BDNF, also known as Brain-derived neurotrophic factor, is encoded by the BDNF Gene family in humans. This is a member of the growth factors that are the neurotrophin family and as such is related to nerve growth factor. This is a neurotrophic factor and, as the name suggests is found in the brain. Research which discovered this dates back to 1989. It was then that Yves-Alain first completed his crucial research on pigs.
BDNF has a range of mechanisms. It does bind more than two receptors on the surface cells which are responsible for responding to the TrkB growth factor as well as the LNGFR. Research also suggests that it can control or restrict activity from various neurotransmitter receptors. This does include the Alpha-7 nicotinic receptor as well as the reelin signalling chain. Indeed, expression of reeling decreases when influenced by BDNF.
BDNF interacts with the TrkB pathway to ensure the development of the growth of neurons as well as the development of short term memory. Furthermore, this interaction does cause the regulation of plasticity but is not regulated after a typical hypoxic injury. As well as this, while the impact of another BDNF receptor and it’s apparent interactions are more complex, every neurotrophin does have the ability to interact with the p75 receptor of BDNF. It is believed that this signalling could result in the triggering of apoptosis. This would be instead of surviving pathways through cells causing the expression of the p75 receptor when there is a decline of Trk receptors. Furthermore, the latest studies suggest that a receptor of TrkB could be a dominant negative of p75.
The protein operates by acting on neurons within the peripheral nervous system as well as the central nervous system. It is used to encourage the survival of neurons and ensure the growth of new neurons as well as synapse. Research has shown that BDNF is active in various parts of the brain including the basal forebrain areas as well as the cortex and hippocampus. Additionally, BDNF does exist outside of the brain and studies have shown it is expressed through everywhere from the retina to the saliva and the prostate. In terms of specific functioning, BDNF will be crucial for long term memory as well as learning. While it’s true that most neurons in humans are formed during prenatal stages, part of the brain does continue to grow neural stem cells. These proteins that are formed control neurogenesis and BDNF is one of the most active. Studies on mice have shown that without BDNF, developmental defects do become apparent and most typically die shortly after being born. Furthermore, various forms of physical exercises seem to cause an increase in BDNF synthesis. This may explain increases in cognitive function after exercise.
BDNF has a structure which means transcription may be controlled by as many as eight different promoters. This does mean that each one leads to various transcripts which do contain one of the eight 5’ exons which have been untranslated and spliced to the 3’encoding exon.