Gallus gallus Raw sequence reads

Early-life development can have a profound impact on later-life coping ability. We hypothesized that early-life environmental complexity would foster a better learning ability and increased neural plasticity in the hippocampus of chicks in a future life challenge. Chicks were brooded in groups having a barren environment (BG), an environment enriched with litter materials (LG), or an environment enriched with perches and litter materials (PLG) until 30 days of age. All chicks were thereafter reared in barren environments (imposing a future life challenge) for 23 days. At 49 days of age, learning ability was tested in a T-maze. At 53 days, the hippocampus was collected and tested by RNA-seq. The treatment groups displayed no difference in learning ability. Plasma creatine kinase concentrations in BG and PLG were lower than in LG. In hippocampal Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, in terms of neural-related gene expression, LG chicks had a down-regulated NEGR1 and NRXN1 in the cell adhesion molecules pathway compared to BG. PLG chicks showed an up-regulated CHRNA8 in the nicotine addiction pathway, and an up-regulated SCGN (related to endocrine and other factor-regulated calcium reabsorption) as compared to LG. In conclusion, early-life environmental complexities had limited effects on learning ability but perches and litter materials in early life improved neural plasticity in the hippocampus of chicks.