The temporal pattern of postnatal neurogenesis found in the neocortex of the Göttingen minipig brain

The Göttingen minipig (G-mini) is increasingly used as a non-primate model for human neurological diseases. We applied design-based stereology on five groups of G-minis aged 1 day, 14 days, 30 days, 100 days, and 2 years or older to estimate the pattern of postnatal neuron number development in the neocortex. Two time periods for the postnatal increase of neocortical neuron number were observed from the time of birth to day 14 (P=0.013) and from day 30 to day 100 (P<0.001). No significant change in neuron number was found from day 14 to 30 (P=0.58) and day 100 onward (P=0.39). The average estimated total number of neurons in the neocortex was 236, 274, 264, 338, and 353 million, respectively. Since neurogenesis and neuronal migration in the human neocortex are generally accepted to be complete before term, the application of G-mini as human disease models may be inappropriate before day 100. However, G-mini may serve as a valuable model for the studies of ongoing neurogenesis in the living brain.