Calcium and calmodulin levels in late embryonic and early hatched Japanese quail brain

Characterizing the last phases of embryonic avian brain development are increased brain activity and increased absorption of shell calcium. The calcium-binding protein, calmodulin, regulates many activities of calcium. In neural tissue, calmodulin modulates neural transmission, and is required for the phosphorylation of synaptosomal proteins. Therefore, the objective was to compare levels of brain calcium and calmodulin in the Japanese quail. Brain extracts from embryonic days 11, 15, hatch, and 5 days post-hatch (n = 7/group) were analysed for calcium, protein and calmodulin. Despite increases in protein between embryonic (X = 0.126 and 0.145 mg/mg wet wt) and hatched groups (X = 0.183 and 0.221 mg), no significant increases in calmodulin were observed (237-279 ng/mg protein). Calcium levels in the brain were U-shaped with low levels at embryonic day 1 (341 micrograms/mg wet wt) and post-hatch day 5 (315 micrograms/mg wet wt) with higher levels on embryonic day 15 (425 micrograms/mg wet wt) and at hatch (433 micrograms/mg wet wt). Calmodulin levels do not show a developmental pattern similar to calcium and protein levels or with reports of brain activity.