by

(Under the Direction of Johanne M. Lewis and Karin Scarpinato) The loss of neurological function due to hypoxia remains to be a challenge in many species due to the lack of knowledge and understanding of cellular responses. To investigate cellular responses and survival strategies of the brain during hypoxia and post-hypoxia recovery in a moderate hypoxia-tolerant species, with the hopes of identifying possible therapeutic remedies, thirty Longhorn sculpin, Myoxocephalus octodecimspinosus, were challenged with acute hypoxia (40 % O2 saturation for 1 h) and twelve additional sculpin were used as controls (~90 % O2 saturation). Fish were sampled at each of the following time points: control/normoxic conditions (T=0 h); hypoxic conditions (T=3 h); early (T=7 h total; 4 hours post-hypoxia), and late (T=11 h total; 8 hours post-hypoxia) normoxic recovery. The importance of hypoxia-induced apoptotic pathways has been suggested in other species; therefore, they were the focus of the present study of the Longhorn sculpin to explore their cellular coping mechanisms to hypoxia. The expression levels of hypoxia-response elements HIF-2α and Hsp70 were examined at the transcriptome level at each time point using RT-QPCR, and HIF-1α, active caspase 3, and survivin, wer