Ntrk2 Conditional Knockout mouse models

Mouse Ntrk2, ortholog of human NTRK2, encodes TrkB, the high affinity receptor for brain-derived neurotrophic factor and neurotrophin 4, whose ligand-induced dimerization activates SHC-RAS-ERK, PI3K-AKT, and phospholipase C gamma 1 signaling to control neuronal survival, dendritic arborization, synaptic potentiation, and hypothalamic energy balance. Alternative splicing generates the kinase-dead TrkB.T1 isoform, which acts as a dominant negative ligand sink and predominates in glia, an isoform architecture that targeting vectors must respect. Human loss-of-function variants produce hyperphagic obesity with developmental delay, while NTRK2 fusions occur in pilocytic astrocytoma and glioblastoma. Germline nulls die within days of birth with severe sensory and motor deficits, so conditional deletion using Camk2a-cre, Nes-cre, or Sim1-cre is required for adult circuit and metabolic endpoints, and isoform-selective alleles are needed to separate full length from truncated receptor function. Ntrk1 and Ntrk3 bind different neurotrophins and do not rescue, so match allele class to whether the question is circuit signaling, obesity, or fusion-driven glioma.

A floxed Ntrk2 allele paired with Cre gives spatial control that whole body knockouts cannot offer. People use it to separate developmental roles from adult homeostasis, to model somatic mutations, and to match disease that begins in one organ.