Influence of Iron Deficiency on Olfactory Behavior in Weanling Rats

Abstract

Chronically high occupational exposure to airborne metals like iron can impair olfactory function, but little is known about how low iron status modifies olfactory behavior. To investigate the influence of body iron status, weanling rats were fed a diet with low iron content (4 – 7 ppm) to induce iron deficiency anemia and olfactory behavior was compared to control rats fed an isocaloric diet sufficient in iron (210 – 220 ppm). Iron-deficient rats had prolonged exploratory time for attractive odorants in behavioral olfactory habituation/dis-habituation tests, olfactory preference tests and olfactory sensitivity tests compared with control rats. No significant differences were observed for aversive odorants between the two groups. These findings suggest that iron-dependent functions may be involved in controlling and processing of olfactory signal transduction via self and lateral inhibition such that odorant signal remains stronger for longer times prolonging exploratory activity on attractive odorants in the behavioral tests. These findings establish that iron deficiency can modify olfactory behavior.

Recognizing the unusual findings: Cases of desiderosmia

“…Ruvin Kumara and Wessling‐Resnick have researched the relationship between low iron condition of the body and behavioral scent functions by using the iron deficiency anemia model induced by diet in rats. As a result of this research, they have found that iron deficiency changes the smelling behavior . This study supports the fact that oddity in smelling behavior of our cases caused by iron deficiency.…”

Desiderosmia: a manifestation of iron deficiency in pregnancy

“…Although research into the relationship between low ferritin and olfactory function in animals has been completed, the same has not been well tested in humans. In studies with rats, it is suggested that iron is a cofactor that controls behavioural olfactory function by participating in signalling through inhibitory pathways, and that iron has a key role in the synthesis of neurons involved in inhibition of odourant signals 14. In studies with piglets, the olfactory bulb was significantly different in size in piglets with severe iron deficiency, indicating the role of iron in other mechanisms 15.…”

Pica for Uncooked Basmati Rice in Two Women with Iron Deficiency and a Review of Ryzophagia

“…It is plausible that the predominant cause of pica associated with iron deficiency or depletion in adults is low tissue iron levels, possibly in the tongue, olfactory apparatus, or other locations in the brain [ 31 , 32 ]. In iron-deficient rats, mean blood 59 Fe levels after intranasal administration of the radioisotope as ferrous or ferric form were significantly higher than those of iron-sufficient control rats [ 33 ]. Divalent metal transporter-1 (DMT1) levels are significantly higher in the olfactory bulbs of iron-deficient rats [ 33 ].…”

“…In iron-deficient rats, mean blood 59 Fe levels after intranasal administration of the radioisotope as ferrous or ferric form were significantly higher than those of iron-sufficient control rats [ 33 ]. Divalent metal transporter-1 (DMT1) levels are significantly higher in the olfactory bulbs of iron-deficient rats [ 33 ]. Thus, the molecular mechanism of olfactory iron absorption and possibly of olfactory or gustatory function involves DMT1 and is influenced by body iron repletion.…”

“…In response to craving, some pregnant women smell particular substances alone or with pica [ 31 , 32 ]. Rats with iron deficiency had longer exploratory times for attractive odorants than control rats [ 33 ].…”