Recent work suggests that depression may be a disorder of neuroplasticity. Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin that signals through tyrosine receptor kinase B (TrkB) to influence synaptic growth and maintenance, and has been implicated in depression. Early life stressors are known to predispose individuals to the later development of depression. We hypothesized that this predisposition is mediated by TrkB/BDNF signalling in early life. Therefore, we utilized a TrkB mutant mouse (TrkBF616A) to reversibly block early postnatal BDNF/TrkB signalling during exposure to early life stress (maternal separation). In 3 month-old mice exposed to maternal separation, we found that TrkB knockdown impacted various aspects of their apparent resiliency to stress in adulthood. Moreover, these mice have very circumscribed variations in the expression of TrkB and BDNF within the brain. We speculate that BDNF might imprint early life stressor events, which ultimately influences the manifestation of depressive illness.