Neurotrofinen

Neurotrofinen is a protein family that plays a crucial role in the survival, growth, differentiation, and function of neurons. The term neurotrophin is derived from "neuron" and "trophic," meaning "nourishing." These proteins act as signaling molecules that promote neuronal health and plasticity.

The most well-known member of the neurotrophin family is nerve growth factor (NGF). Other prominent neurotrophins include brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). Each neurotrophin has specific receptors, known as Trk receptors (tyrosine receptor kinases), which are essential for mediating their effects. For example, NGF primarily binds to TrkA, BDNF and NT-4/5 bind to TrkB, and NT-3 binds to TrkC. Neurotrophins also interact with a coreceptor called p75NTR, which can modulate their signaling.

Neurotrophins are synthesized in various tissues, including the nervous system and peripheral organs. They are released in response to neuronal activity, injury, or physiological stress. Once released, they can act locally or be transported over longer distances to influence target neurons. Their functions are diverse, encompassing the regulation of neuronal survival, the promotion of axon growth and guidance during development, the maintenance of synaptic connections, and the modulation of synaptic plasticity, which is fundamental for learning and memory.

Dysregulation of neurotrophin signaling has been implicated in a variety of neurological and psychiatric disorders, including Alzheimer's disease, Parkinson's disease, depression, and anxiety. Consequently, neurotrophins are considered potential therapeutic targets for these conditions, with research ongoing to develop strategies that can modulate their levels or activity for treatment.