Method for Staining Bacterial Flagella

The following method of staining bacterial flagella is ecommended for use on smears made from suspensions of 10 to 16-tour agar slant cultures, incubated 30 minutes at 37°C before spreadng on thoroly cleaned and named slides:

1. Cover with fixative (100 cc. of 1/4 sat. aqu. solution picric acid, with 5 g. tannic acid and 7.5 g. ferrous sulfate).
2. Wash with tap water, dry and cover with Fontana spirochaete stain; heat to steaming and allow to act for 1 to 2 minutes. Wash in ap water. The stain is prepared as follows: To 25 cc. 2% AgNO₃ add dilute ammonia till the precipitate which forms redissolves; then add more AgNO₃ till a faint turbidity results. A clear solution is useess.

     

Turning in circles: The neuropharmacology of rotation

Animals with unilateral lesions of the nigrostrial system rotate when administered dopaminergic agents. The same agents also induce rotation, though at lower rates, in normal animals. Despite the apparent simplicity of the rotatory response, variations in methodology among studies may alter the kind and/or magnitude of rotation data obtained. In some cases, due to insufficient control procedures, inaccurate or erroneous interpretations may be reached. The importance of considering several testing parameters is discussed. It is concluded that rotation is primarily due to asymmetric dopaminergic nigrostriatal function, although other pathways mediated by norepinephrine, serotonin, acetylcholine and GABA appear to have modulatory roles.