ABSTRACT
Many diabetic individuals develop anosmia but the mechanism(s) causing the dysfunction in the olfactory system is (are) unknown. Glial fibrillary acidic protein expression is reduced in diabetic retinopathy and is also reduced, with unknown consequences, in other brain regions of diabetic rats. We used immunohistochemistry and immunoblotting from untreated control and streptozotocin-induced type 1 (insulin dependent) diabetic rats to investigate main olfactory epithelial mitotic rate and glial fibrillary acidic protein expression in the lamina propria of the sensory epithelium and in the olfactory bulb. Numbers of bromodeoxyuridine-positive cells were significantly lower in the diabetic sensory epithelium compared to non-diabetic controls. Immunohistochemical observations suggested a qualitative difference in glial fibrillary acidic protein expression in both regions examined especially in the olfactory bulb external plexiform layer and the lamina propria. Immunoblot analysis confirmed that the diabetic olfactory bulb and lamina propria expressed less glial fibrillary acidic protein compared to the non-diabetic control group. The lower expression levels in the olfactory bulb external plexiform layer suggested by immunohistochemistry do not reflect a change in the number of astrocytes since the numbers of S100B(+) cells were not different between the two groups.
Subject(s)
Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Glial Fibrillary Acidic Protein/analysis , Mitosis/physiology , Olfactory Bulb/chemistry , Olfactory Bulb/pathology , Animals , Cell Count , Cytoskeleton/physiology , Diabetic Neuropathies/pathology , Diabetic Neuropathies/physiopathology , Fluorescent Antibody Technique , Glial Fibrillary Acidic Protein/physiology , Immunoblotting , Immunohistochemistry , Male , Mucous Membrane/chemistry , Mucous Membrane/pathology , Mucous Membrane/physiopathology , Nasal Bone/chemistry , Nasal Bone/pathology , Nasal Bone/physiopathology , Olfaction Disorders/pathology , Olfaction Disorders/physiopathology , Olfactory Bulb/physiopathology , Olfactory Mucosa/chemistry , Olfactory Mucosa/pathology , Olfactory Mucosa/physiopathology , Rats , Rats, WistarABSTRACT
Twenty-nine third-grade teachers and selected students from their classes participated. Study 1 used teacher interviews and classroom observations to examine teachers' perceptions and practices for grouping for reading instruction; Study 2 examined the impact of these grouping practices on the academic progress, social progress, and attitudes about reading of students representing a range of achievement levels, including students with learning disabilities. Results indicated that, overall, teachers used whole class instruction for reading and the same materials for all students, including students with learning disabilities. Students with learning disabilities made little academic progress and their attitudes about reading did not improve over time.
