Question

List three major families of neurotrophic factors.

Short answer

Answer: The three major families of neurotrophic factors are Neurotrophins, Glial cell-derived neurotrophic factors (GDNF) family, and Neuropoietic cytokines. Neurotrophins, including NGF, BDNF, NT-3, and NT-4/5, promote growth, survival, and differentiation of neurons. The GDNF family, consisting of GDNF, NRTN, PSPN, and ARTN, focuses on the development and maintenance of dopamine and motor neurons. Neuropoietic cytokines, such as IL-6, CNTF, and LIF, regulate neural cell functions like survival and development.

Step-by-step solution

Definition of neurotrophic factors

Neurotrophic factors are proteins that help promote the growth, survival, and differentiation of developing and mature neurons. They play a crucial role in the maintenance and regeneration of neurons in the nervous system.

Identify the families of neurotrophic factors

The three major families of neurotrophic factors are: 1. Neurotrophins 2. Glial cell-derived neurotrophic factors (GDNF) family 3. Neuropoietic cytokines

Provide explanations for each family

1. Neurotrophins: This family consists of proteins like nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). They primarily bind to the tropomyosin receptor kinase (Trk) family of receptor tyrosine kinases and the p75 neurotrophin receptor (p75NTR). 2. Glial cell-derived neurotrophic factors (GDNF) family: This family includes proteins such as GDNF, neurturin (NRTN), persephin (PSPN), and artemin (ARTN). They bind to the GFR-alpha and bioactive receptor complexes and are mainly involved in the development and maintenance of dopamine and motor neurons. 3. Neuropoietic cytokines: These are a group of growth factors that regulate neural cell functions, including survival and development. This family includes proteins such as interleukin-6 (IL-6), ciliary neurotrophic factor (CNTF), and leukemia inhibitory factor (LIF). They usually act through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway.