Examining the effect of iron (ferric) on physiological processes: Invertebrate models

Iron is a common and essential element for maintaining life in bacteria, plants and animals and is found in soil, fresh waters and marine waters; however, over exposure is toxic to organisms. Iron is used in electron transport complexes within mitochondria as well as a co-factor in many essential proteins. It is also established that iron accumulation in the central nervous system in mammals is associated with various neurological disorders. Ample studies have investigated the long-term effects of iron overload in the nervous system. However, its acute effects in nervous tissue and additional organ systems warrant further studies. This study investigates the effects of iron overload on development, behavior, survival, cardiac function, and glutamatergic synaptic transmission in the Drosophila melanogaster. Additionally, physiological responses in crayfish were examined following Fe³⁺ exposure. Fe³⁺ reduced neuronal excitability in proprioceptive neurons in a crayfish model. Thus, Fe³⁺ may block stretch activated channels (SACs) as well as voltage-gated Na⁺ channels. Exposure also rapidly reduces synaptic transmission but does not block ionotropic glutamatergic receptors, suggesting a blockage of pre-synaptic voltage-gated Ca²⁺ channels in both crustacean and Drosophila models. The effects are partly reversible with acute exposure, indicating the cells are not rapidly damaged. This study is relevant in demonstrating the effects of Fe³⁺ on various physiological functions in different organisms in order to further understand the acute and long-term consequences of overload.