Faculty Collaboration Database

Hypothyroidism impairs late LTP in CA1 region but not in dentate gyrus of the intact rat hippocampus: MAPK involvement. Hippocampus 2004;14(1):40-5

Date

04/03/2004

Pubmed ID

15058481

DOI

10.1002/hipo.10165

Scopus ID

2-s2.0-1542395750 (requires institutional sign-in at Scopus site)   109 Citations

Abstract

Thyroid hormone activates extracellular signal-regulated kinases (ERK1 and ERK2), which are important in late long-term potentiation (L-LTP). The aim of this study was to determine the possible mechanism underlying the impairment of L-LTP as a result of hypothyroidism. We investigated the effect of hypothyroidism on L-LTP of the two associative pathways in the hippocampus: the Schaffer collateral synapses and the perforant path synapses. We also examined the effect of hypothyroidism on ERK1 and ERK2 levels in both the CA1 and dentate gyrus (DG) regions of the hippocampus. Electrophysiological recordings from hippocampi of anesthetized rats show that hypothyroidism impairs L-LTP in CA1 region, but not in the DG. Western blot analysis of the CA1 region shows that hypothyroidism decreases phosphorylated ERK1 and ERK2 levels without affecting their total levels. In the DG of the hypothyroid rat, however, there was no significant change in the levels of phosphorylated or total ERKs. The correlation between the effect of hypothyroidism on L-LTP and enzyme levels suggests that hypothyroidism-induced impairment of L-LTP in CA1 may be due to decreased levels of phosphorylated ERK1 and ERK2.

Author List

Gerges NZ, Alkadhi KA

Author

Nashaat Gerges PhD Chair, Professor in the School of Pharmacy Administration department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Action Potentials
Animals
Dentate Gyrus
Down-Regulation
Excitatory Postsynaptic Potentials
Hippocampus
Hypothyroidism
Long-Term Potentiation
MAP Kinase Signaling System
Male
Memory Disorders
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase 3
Mitogen-Activated Protein Kinases
Neural Pathways
Phosphorylation
Presynaptic Terminals
Rats
Rats, Wistar
Synaptic Transmission