title: Modulation by TRH of NMDA-elicited responses of CA1 neurones of the rat hippocampal slice preparation.
abstract: Intracellular recording from CA1 neurones of the rat hippocampal slice preparation was carried out to assess the ability of the endogenously-occurring neuropeptide thyrotropin-releasing hormone (TRH) to modulate responses elicited by the excitatory amino acid agonist N-methyl-D-aspartate (NMDA). TRH (5 microM) produced no change in resting membrane potential or input resistance but facilitated on-going synaptic activity. In the continuous presence of the peptide responses to NMDA were selectively enhanced for about 20 min. In approximately 50% of cells the potentiating effect of TRH persisted in tetrodotoxin (TTX) solution and was associated with removal of the apparent voltage-dependent increase in input resistance usually found during the NMDA-induced depolarization. It is suggested that TRH evoked a transient upregulation of NMDA responses which might account for the reported facilitation by this peptide of long term potentiation in the hippocampus.
authors.affiliation: Biophysics Laboratory, International School for Advanced Studies (SISSA), Trieste, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Stocca
authors.forename: A
authors.initials: A
authors.lastname: Nistri
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000818:Animals; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D013569:Synapses / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000502:physiology*
chemical_list: D011810:Quinoxalines; D013779:Tetrodotoxin; D013973:Thyrotropin-Releasing Hormone; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione