ABSTRACT
Aiming to extend previous findings, male Wistar rats were treated per os for 13 weeks with manganese chloride in two doses: 300 mg/kg body weight (group I) and 20 mg/kg b.w. (II), the former was associated (III) with a microdose (1 ppm) of natrium selenite. The findings show an impairment of active avoidance learning in group III, a decrease of swimming performance and histological lesions in several brain areas (both especially in group III), changes of the aggressive behavior and decreases in the brain tissue of superoxide dismutase activity (I & II) and of lipid peroxidation (in all groups).
Subject(s)
Behavior, Animal/drug effects , Chlorides , Manganese Compounds , Manganese Poisoning , Selenium/toxicity , Animals , Behavior, Animal/physiology , Brain/drug effects , Brain/metabolism , Dose-Response Relationship, Drug , Lipid Peroxides/metabolism , Male , Rats , Rats, Inbred Strains , Selenious Acid , Superoxide Dismutase/metabolismABSTRACT
6-Hydroxydopamine (6-OHDA) injected into the lateral cerebral ventricles of rats impaired their exercise performance until exhaustion (treadmill run and swimming). The injected rats displayed significantly less training-induced improvement of swimming performance than did the control animals. Reduced performance also was seen in adult rats treated intraperitoneally with 6-OHDA in the neonatal or adult periods. The functional impairment can be explained by the neurotoxic action of 6-OHDA on monoamine brain structures (substantia nigra and locus ceruleus) and/or on peripheral sympathetic innervation, the latter assessed by histofluorescence of the iris muscle. The possible contribution of lacticacidemia to the reduced tolerance to stress of 6-OHDA-treated rats by the intracerebroventricular route also is considered.
Subject(s)
Hydroxydopamines/pharmacology , Physical Exertion/drug effects , Adaptation, Physiological , Adrenal Medulla/physiology , Animals , Hydroxydopamines/administration & dosage , Injections, Intraperitoneal , Injections, Intraventricular , Male , Oxidopamine , Rats , Rats, Inbred Strains , Swimming , Sympathetic Nervous System/physiologyABSTRACT
An injection of 250 micrograms 6-OHDA into the right cerebral ventricle of adult rats tested after 45 days led to a reduction of the run performance on the treadmill compared with the control group, but only in the first period of this test, repeated 10-11 times, every 2-3 days. This behavior was more obvious in male and in exercise-enduring rats. The histological examination proved partial destruction of central monoaminergic (especially dopaminergic) structures in the 6-OHDA treated rats. 24-48 hours after peripheral injections of 6-OHDA (100 mg/kg b. w.) a considerable reduction of the run and swim performance (acute exercise till exhaustion) occurred. Falck's histofluorescence method proved large destructions of the noradrenergic innervation in the iris; 6-OHDA injected i.p. into neonatal rats had similar effects.
Subject(s)
Hydroxydopamines/pharmacology , Motor Activity/drug effects , Physical Exertion/drug effects , Animals , Female , Injections, Intravenous , Injections, Intraventricular , Male , Rats , Running , SwimmingABSTRACT
A considerable reduction of the run performance (tread-mill test) and a smaller impairment of the swimming capacity occurs in adult rats injected intraperitoneally in the neonatal period with three doses of 50 mg/kg b.w. or 6-hydroxydopamine. In other rats treated i. p. with disulfiram (200 mg/kg) the run performance was significantly reduced. These data, together with histological observations, show the important role of central and peripheral noradrenergic, and not only dopaminergic, mediation in the control of motor behaviour.
Subject(s)
Biogenic Amines/antagonists & inhibitors , Disulfiram/pharmacology , Hydroxydopamines/pharmacology , Physical Exertion/drug effects , Animals , Animals, Newborn , Body Weight/drug effects , Female , Male , Motor Activity/drug effects , Rats , SwimmingABSTRACT
In rats injected in the cerebral ventricle with 250 micrograms of 6-hydroxydopamine a significant blockade of the improvement of swimming performance due to training occurs. The central injection of 6-OHDA leads to a lengthening of the total latency time (LT) of active conditioned reaction in shuttle box and of the LT of netative escape responses during learning, but not of the positive avoidance responses. 6-OHDA injected after the learing schedule (12 days) has no effect on the LT during relearning and extinction. Therefore a partial destruction of central monoaminergic, and especially of dopaminergic, neurons impairs particularly the acquisition but not the retention of the motor program.
