Effects of gestational and lactational exposure to low dose mercury chloride (HgCl2) on behaviour, learning and hearing thresholds in WAG/Rij rats

Authors

  • Deniz Sahin Kocaeli University / Medical Faculty, Physiology, Kocaeli, Turkey
  • Cem Onur Erdolu Kocaeli University / Medical Faculty, Kocaeli, Turkey
  • Sabriye Karadenizli Kocaeli University / Medical Faculty, Physiology, Kocaeli, Turkey
  • Ahmet Kara Sakarya University Training and Research Hospital, Otorhinolaryngology Department, Sakarya,Turkey
  • Gunce Bayrak Kocaeli University / Medical Faculty, Kocaeli, Turkey
  • Sumeyye Beyaz Kocaeli University / Medical Faculty, Kocaeli, Turkey
  • Buse Demir Kocaeli University / Medical Faculty, Kocaeli, Turkey
  • Nurbay Ates Kocaeli University / Medical Faculty, Physiology, Kocaeli, Turkey

DOI:

https://doi.org/10.17179/excli2016-315

Keywords:

inorganic mercury, passive avoidance, DPOAE test, Morris watermaze, hearing thresholds, WAG/Rij rats

Abstract

We investigated the effects of inorganic mercury exposure during gestational/lactational periods on the behaviour, learning and hearing functions in a total of 32, 5-week-old and 5-month-old WAG/Rij rats (equally divided into 4 groups as 5-week and 5-month control mercury exposure groups). We evaluated the rats in terms of locomotor activity (LA), the Morris-water-maze (MWM) test and the passive avoidance (PA) test to quantify learning and memory performance; we used distortion product otoacoustic emission (DPOAE) tests to evaluate hearing ability. There were no significant differences between the 5-week-old rat groups in LA, and we detected a significant difference (p < 0.05) in the HgCl2-treated group in PA, MWM and DPOAE tests compared with the control group. The HgCl2-treated 5-week-old group exhibited worse emotional memory performance in PA, worse spatial learning and memory performances in MWM. There were no significant differences between the groups of 5-month-old rats in LA, MWM or PA. However, the DPOAE tests worsened in the mid- and high-frequency hearing thresholds. The HgCl2-treated 5-month-old group exhibited the most hearing loss of all groups. Our results convey that mercury exposure in young rats may worsen learning and memory performances as well as hearing at high-frequency levels. While there was no statistically significant difference in the behavior and learning tests in adult rats, the DPOAE test produced poorer results. Early detection of effects of mercury exposure provides medicals team with an opportunity to determinate treatment regimens and mitigate ototoxicity. DPOAE test can be used in clinical and experimental research investigating heavy metal ototoxicity.

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Published

2016-06-21

How to Cite

Sahin, D., Erdolu, C. O., Karadenizli, S., Kara, A., Bayrak, G., Beyaz, S., … Ates, N. (2016). Effects of gestational and lactational exposure to low dose mercury chloride (HgCl2) on behaviour, learning and hearing thresholds in WAG/Rij rats. EXCLI Journal, 15, 391–402. https://doi.org/10.17179/excli2016-315

Issue

Vol. 15 (2016)

Section

Original articles

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