Temporal Pattern Of Recovery Research Articles

Preoperative operant circling training facilitates recovery following unilateral substantia nigra lesion in rats

This study was undertaken to examine (1) whether pre- and/or postoperative training, using water reinforcement, to turn in circles (rotation) affects the behavioral symptoms induced by unilateral 6-hydroxydopamine (6-OHDA)-induced DA denervation of the rat substantia nigra (SN); (2) whether there was any influence of this training on the temporal pattern of recovery; and (3) whether the rotational training influences turning induced by systemic injection of dopaminergic drugs. In the first experiment, rats were trained either ipsi- or contraversive (TI or TO) to the side to be damaged 11 days before and 23 days after lesion, and tested in an open field for rotational behavior following systemic administration of apomorphine and amphetamine. In the second experiment rats were trained only before the lesion was made and tested in the open field for spontaneous circling and thigmotactic behavior. The results of the first experiment indicated maintenance of the training performance after the lesion. At the 14th day after the lesion, the ipsiversive trained group showed a higher contraversive circling frequency after apomorphine injection in relation to the contralateral trained group. In the second experiment, rats trained only before the surgery, showed asymmetrical spontaneous circling in the trained direction before and 14 days after surgery, indicating, in a drug free condition, that training direction can be restored after unilateral SN lesions, even to the contralateral body side. Moreover, thigmotactic behavior indicated a lack of habituation in an open field in unilateral lesion rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery of benthic invertebrate communities in silver bow creek, montana, following improved metal mine wastewater treatment

Silver Bow Creek, a tributary of the Clark Fork River in southwest Montana, has been affected by metal mining and domestic wastes for over 100 yr. The invertebrate community was monitored at five stations from 1972 through 1983 to determine both the longitudinal and temporal patterns of recovery following major improvements in mine wastewater treatment. This treatment dramatically reduced metal concentrations in the mine discharge. Despite markedly improved water quality, no invertebrates were collected in Silver Bow Creek until 1975, when small numbers of invertebrates (primarily chironomids) were collected at the furthest downstream stations. A few invertebrates ( 1600 m−2). The earliest colonizers at each station were chironomids, empidids, and oligochaetes. In 1982, 10 yr after initiation of improved water quality, aquatic insect populations were over 1800 m−2 at all five stations. Populations dropped in 1983, but upper and lower stations had comparable densities suggesting that the stream is responding to a common stress such as high snowmelt runoff. The relatively long recovery time is partially attributed to the lack of an undisturbed headwater source of colonizers.

Recovery of proliferative capacity of agar colony-forming cells and spleen colony-forming cells following ionizing radiation or vinblastine.

AbstractThe effects of sublethal radiation and the mitotic inhibitor, vinblastine sulphate, on the number of cells in mouse bone marrow capable upon transplantation of forming macroscopic colonies on the surface of the spleens of irradiated recipient mice (CFU) and on the number of cells capable of forming colonies in soft agar after cell culture (ACFU) were studied as a function of time after injury. The results show that ACFU are radiosensitive and vinblastine‐sensitive cells, comparable in sensitivity to erythropoietin‐sensitive cells. The temporal pattern of recovery following radiation of ACFU, different from that for CFU, is compatible with the concept that these are two distinct but closely related stem cell populations. The relevance of these findings to models of hematopoiesis and to studies on the precursors of macrophages and monocytes in inflammatory exudates is discussed.