BDNF and brain injury: When viewing the observation of increased IGF-1, and a tendency for increased BDNF, in piglets after a brief exposure to EE alongside previous rodent and human studies of increased IGF-1 correlating with learning, mood and recovery from brain injury, it would suggest that in pigs short-term exposure to EE results in: 1) increased positive affect; 2) increases in synaptogenesis and plasticity, with concomitant beneficial effects on learning, memory and cognitive development and 3) increases in neuroprotection with prolonged positive effects on ‘brain health’.