Effect of cooling of the culmen of the cerebellar vermis on chemically induced stepping in guinea pigs.
A regular 'stepping automatism' was induced via our recently reported SIS (substances capable of inducing stepping) in guinea pigs. Reversible cooling (5-0 degrees C) or partial ablation of the culmen of the cerebellar vermis could facilitate SIS-induced stepping, whereas electrical stimulation (300 microA up) of the same region could attenuate or abolish stepping. Cooling could only facilitate, but not trigger stepping movements. The above-mentioned facilitation was most prominent in those guinea pigs that exhibited a weak stepping automatism. Cooling of the lateral part of the culmen of the cerebellar vermis and hemisphere mainly facilitated stepping of the ipsilateral forelimb. When the interfacial temperature between the cooling probe and tentorium cerebelli was appropriate (5-0 degrees C), cooling could mimic the effects of ablation to a great extent.
D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D003080:Cold Temperature; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects; D008297:Male; D005466:Fluorocarbons
D007093:Imidazoles; C051906:2,2,5,5-tetrakis(trifluoromethyl)-3-imidazoline; D005466:Fluorocarbons