Zinc deficiency enhances salt preference through altered peripheral and central taste processing mechanisms

Area of Science:

• Neuroscience
• Nutritional Science
• Physiology

Background:

• Zinc deficiency is known to alter taste preferences, but the neural mechanisms are not fully understood.
• Altered salt preference may involve changes in brain regions controlling gustatory processing and fluid balance.

Purpose of the Study:

• To investigate the neural mechanisms underlying altered salt preference in zinc deficiency.
• To examine the impact of zinc deficiency on neuronal activity in the brainstem and hypothalamus related to salt taste and fluid regulation.

Main Methods:

• Taste behavioral tests were conducted on zinc-deficient rats, including chorda tympani nerve transection (CTx) and sodium channel blocker administration.
• Neuronal activity was assessed by measuring c-Fos-like protein expression in the parabrachial nuclei (PBN), supraoptic nucleus (SON), and paraventricular nucleus (PVN).

Main Results:

• Zinc-deficient rats exhibited increased preference for high salt concentrations.
• Neither CTx nor amiloride altered salt preference in zinc-deficient rats.
• High salt stimulation resulted in reduced c-Fos expression in the PBN, SON, and PVN of zinc-deficient rats compared to controls.

Conclusions:

• Zinc deficiency disrupts sodium chloride (NaCl) reception and alters neuronal responses in gustatory and fluid balance pathways.
• These neural alterations potentially lead to modified NaCl ingestive behaviors in zinc deficiency.
• The study provides insights into the neural basis of taste dysfunction and altered salt preference associated with zinc deficiency.