Description of clinical and histopathological scores postsarin exposure
Rats were exposed to sarin (108 mg/kg, ∼1.2 LD50 i.m. with a supportive treatment) as described under Materials and Methods and observed for clinical symptoms and weight monitoring. Postexposure (48 h), rats were sacrificed, and brains were fixed and processed routinely for paraffin embedding and further evaluated by light microscopy analysis. Both clinical and histological observations were scored using a scoring scale that is based on the well characterized symptoms and brain damage induced by OP. Each score includes all the above symptoms plus the added one.
Score | Clinical Symptoms | Histopathological Evaluation |
|---|---|---|
| 0 | Normal behavior | Normal morphology |
| 1 (minimal) | Grooming and piloerection | Enlargement of ventricles, few pyknotic cells |
| 2 (mild) | Salivation and tremor | Typical OP damage (loss of cells and vacuolization) in one of three vulnerable regions (piriform cortex, hippocampus, thalamus) |
| 3 (moderate) | Impairments in motor activity and weight loss | Typical OP damage in two of three vulnerable regions (see above) |
| 4 (moderate to severe) | Dyspnea | Typical OP damage in the three vulnerable regions |
| 5 (severe) | Convulsions | Degeneration over 50% of cells in the three vulnerable regions including additional brain regions such as septum and amygdala |