Hypoxia-induced ABR change and heat shock protein expression in the pontine auditory pathway of young rabbits.
The auditory brainstem response (ABR) was compared with the immunohistochemical expression of heat shock protein (HSP-72) and microtubule-associated protein 2 (MAP-2) of the brainstem auditory pathway in young rabbits subjected to hypoxic stress. Severe hypoxia for 2 h produced significant prolongation and decreased amplitude of the later component of ABR. HSP-72 expression was distinctly increased in the cochlear nucleus, but there was less induction in the inferior colliculus under severe hypoxia. MAP-2 immunostaining of neuropiles in the inferior collicular nucleus was decreased slightly after severe-long hypoxia, but cytoplasmic staining did not change. The present ABR change, which was produced by brainstem hypoxia-ischemia and acidosis, may be due to the neural cytoarchitectural derangement and less induction of stress proteins in the upper brainstem.
Inagaki
M
M
National Institute of Mental Health, National Center of Neurology and Psychiatry (NCNP), Ichikawa, Japan.
Kaga
M
M
Isumi
H
H
Hirano
S
S
Takashima
S
S
Nanba
E
E
D000818:Animals; D001306:Auditory Pathways / Q000502:physiology* / Q000503:physiopathology; D001639:Bicarbonates / Q000097:blood; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D050884:HSP72 Heat-Shock Proteins; D006339:Heart Rate; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D000860:Hypoxia; D007150:Immunohistochemistry; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D009928:Organ Specificity; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011149:Pons / Q000502:physiology* / Q000503:physiopathology; D011817:Rabbits
D001639:Bicarbonates; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D008869:Microtubule-Associated Proteins; D002245:Carbon Dioxide; D010100:Oxygen