Experiential factors in the expression of hypermotility produced by intradentate colchicine: Lack of effect of GM1 ganglioside on colchicine‐induced loss of granule cells and mossy fibers

Abstract

Adult male Fischer-344 rats were given bilateral injections of 2.5 micrograms colchicine or artificial cerebrospinal fluid into caudal and rostral sites of the dentate gyrus of the hippocampus. One group of rats received 21 consecutive daily injections of 20 mg/kg GM1 gangliosides, i.p., beginning the day prior to surgery. Another group received saline. Colchicine-induced hypermotility was not seen in animals repeatedly handled 21 d after surgery, in spite of significant decreases in granule cell number and decreases in the volume of hippocampal mossy fibers. Pretreatment with GM1 had no effect on behavior and it did not protect against the hippocampal damage produced by colchicine. Rats given colchicine, but not handled for 21 d, showed significant hypermotility, which was associated with decreases in hippocampal granule cells. These data underscore the importance of handling in postlesion functional recovery.