Alterations in the dopaminergic system and behaviour in rats reared on iodine-deficient diets.
Male rats raised on an iodine-deficient diet were found to be retarded in growth rate, to have lowered body temperature, and to have poorer memory retention of a passive avoidance task than rats raised on a similar diet but with adequate iodine concentration. In addition, the iodine deficient rats showed increased locomotor activity and sniffing frequency after the dopamine agonist, apomorphine; while their operant performance was inhibited to a greater degree after apomorphine. However, the hypothermic effects of apomorphine were comparable in both iodine-deficient and normal rats. At sacrifice the iodine-deficient rats were found to have significantly depressed thyroxine levels (less than 10% of normal), significantly elevated TSH levels (greater than 700% of normal), and a significantly greater concentration of dopamine receptors in the striatum (28% increase). Thus, rats raised on iodine-deficient diets have considerable behavioural and physiological alterations, including an increased concentration of dopamine receptors.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000502:physiology*; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects; D004032:Diet; D004298:Dopamine / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology; D007037:Hypothyroidism / Q000503:physiopathology; D007455:Iodine / Q000172:deficiency*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D013972:Thyrotropin; D007455:Iodine; D006220:Haloperidol; D001058:Apomorphine; D013974:Thyroxine; D004298:Dopamine