Nitric oxide contributes to learning and memory deficits observed in hypothyroid rats during neonatal and juvenile growth

Hosseini, M. and Dastghaib, S. S. and Rafatpanah, H. and Hadjzadeh, M. A. R. and Nahrevanian, H. and Farrokhi, I. (2010) Nitric oxide contributes to learning and memory deficits observed in hypothyroid rats during neonatal and juvenile growth. Clinics, 65 (11). pp. 1175-1181.

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INTRODUCTION: Severe cognitive impairment follows thyroid hormone deficiency during the neonatal period. The role of nitric oxide (NO) in learning and memory has been widely investigated. METHODS: This study aimed to investigate the effect of hypothyroidism during neonatal and juvenile periods on NO metabolites in the hippocampi of rats and on learning and memory. Animals were divided into two groups and treated for 60 days from the first day of lactation. The control group received regular water, whereas animals in a separate group were given water supplemented with 0.03 methimazole to induce hypothyroidism. Male offspring were selected and tested in the Morris water maze. Samples of blood were collected to measure the metabolites of NO, NO2, NO3 and thyroxine. The animals were then sacrificed, and their hippocampi were removed to measure the tissue concentrations of NO2 and NO3. DISCUSSION: Compared to the control group's offspring, serum thyroxine levels in the methimazole group's offspring were significantly lower (P<0.01). In addition, the swim distance and time latency were significantly higher in the methimazole group (P<0.001), and the time spent by this group in the target quadrant (Q1) during the probe trial was significantly lower (P<0.001). There was no significant difference in the plasma levels of NO metabolites between the two groups; however, significantly higher NO metabolite levels in the hippocampi of the methimazole group were observed compared to controls (P<0.05). CONCLUSION: These results suggest that the increased NO level in the hippocampus may play a role in the learning and memory deficits observed in childhood hypothyroidism; however, the precise underlying mechanism(s) remains to be elucidated. © 2010 CLINICS.

Item Type: Article
Additional Information: Cited By :39 Export Date: 16 February 2020 Correspondence Address: Hosseini, M.; Neuroscience Research Center, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran; email:
Uncontrolled Keywords: Hypothyroidism Learning Memory Nitric oxide Offspring antithyroid agent nitric oxide synthase thiamazole thyroxine animal article blood chemically induced disorder female hippocampus learning disorder memory disorder metabolism rat time Wistar rat Animals Antithyroid Agents Learning Disorders Memory Disorders Methimazole Rats Rats, Wistar Time Factors
Subjects: WS Pediatrics
Divisions: Mashhad University of Medical Sciences
Depositing User: mr lib4 lib4
Date Deposited: 02 Mar 2020 05:56
Last Modified: 02 Mar 2020 05:56

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