Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/1996
Publication Date: N/A
Technical Abstract: The domestic pig (SUS SCROFA) is used for agricultural production and as a biomedical model. Aims were to determine age effects and diverse environments on development of the neocortex, behavior and immunity. Littermates (6 sets, half-sib, female) were randomly assigned to one of 3 treatments: euthanized at birth, or raised crossfostered and in an indoor, simple environment (fan ventilation and concrete floors) or an outdoor, complex environment (straw on earth). After 8 weeks, behaviors were observed, blood was collected for immune measures, and pigs euthanized for brain tissue samples. The primary auditory, somatosensory and visual neocortex were sectioned (Golgi-Cox staining). Non-truncated, layer IV neurons (n = 493) were digitized (Eutectics Neuron Tracing System). Soma area increased 15% (P<.01) in all 3 neocortex regions from birth to 8 weeks. Auditory cells decreased in length, membrane surface area and had fewer segments (all P <.001) at 8 weeks compared with birth. Visual corte cells increased in length and membrane surface area (P<.05) at 8 weeks compared with birth. Pigs reared in more complex outdoor environments had more auditory dendritic segments than pigs reared indoors (4.86 vs. 4.24+/0.22, P<.01). Outdoor pigs were more active and showed greater rooting (P<.05) than indoor pigs. Outdoor pigs had more white blood cells (P<.05) than indoor pigs, but lymphocyte proliferation, neutrophil chemotaxis and NK activity were similar for each. Diverse environments did not lead to neuroanatomical signs of deprivation.