Article

Imipramine counteracts corticosterone-induced enhancement of glutamatergic transmission and impairment of long-term potentiation in the rat frontal cortex.

Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, PL 31-343 Kraków, Poland.
Pharmacological reports: PR (Impact Factor: 2.17). 11/2011; 63(6):1404-12. DOI: 10.1016/S1734-1140(11)70704-6
Source: PubMed

ABSTRACT The effects of corticosterone administration lasting for 7 and 21 days were studied ex vivo in rat frontal cortex slices prepared 48 h after the last dose of the hormone. In slices originating from corticosterone-treated animals, the amplitude of extracellular field potentials recorded in cortical layer II/III was increased. Corticosterone administration also resulted in an increase of the mean frequency, but not the mean amplitude, of spontaneous excitatory postsynaptic currents (sEPSCs) in layer II/III pyramidal neurons. These effects were accompanied by a reduced magnitude of long-term potentiation (LTP) of field potentials. In a separate set of experiments, rats were treated with corticosterone for 21 days and additionally with a tricyclic antidepressant, imipramine, beginning on the eighth day of corticosterone administration. In this experimental group, the amplitude of field potentials, the mean frequency of sEPSCs and the magnitude of LTP were not different from the control, indicating that corticosterone-induced modifications of basal glutamatergic transmission and synaptic plasticity were reversed by the antidepressant.

Download full-text

Full-text

Available from: Grzegorz Hess, Jun 20, 2015
0 Followers
 · 
164 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of prenatal stress procedure were investigated in 3 months old male rats. Prenatally stressed rats showed depressive-like behavior in the forced swim test, including increased immobility, decreased mobility and decreased climbing. In ex vivo frontal cortex slices originating from prenatally stressed animals, the amplitude of extracellular field potentials (FPs) recorded in cortical layer II/III was larger, and the mean amplitude ratio of pharmacologically-isolated NMDA to the AMPA/kainate component of the field potential-smaller than in control preparations. Prenatal stress also resulted in a reduced magnitude of long-term potentiation (LTP). These effects were accompanied by an increase in the mean frequency, but not the mean amplitude, of spontaneous excitatory postsynaptic currents (sEPSCs) in layer II/III pyramidal neurons. These data demonstrate that stress during pregnancy may lead not only to behavioral disturbances, but also impairs the glutamatergic transmission and long-term synaptic plasticity in the frontal cortex of the adult offspring.
    PLoS ONE 03/2015; 10(3):e0119407. DOI:10.1371/journal.pone.0119407 · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An experimental model of schizophrenia was established using dizocilpine (MK-801). Rats were intragastrically administered with Wendan decoction or clozapine for 21 days prior to establishing the model. The results revealed that the latency of schizophrenia model rats to escape from the hidden platform in the Morris water maze was significantly shortened after administration of Wendan decoction or clozapine. In addition, the treated rats crossed the platform significantly more times than the untreated model rats. Moreover, the rate of successful long-term potentiation induction in the Wendan decoction group and clozapine group were also obviously increased compared with the model group, and the population spike peak latency was significantly shortened. These experimental findings suggest that Wendan decoction can improve the learning and memory ability of schizophrenic rats to the same extent as clozapine treatment.
    Neural Regeneration Research 05/2012; 7(15):1132-7. DOI:10.3969/j.issn.1673-5374.2012.15.002 · 0.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The mechanisms of the influence of prolonged stress on glutamatergic transmission and synaptic plasticity in the cerebral cortex remain poorly understood. The purpose of this study was to determine an involvement of interleukin-1β (IL-1β) in the effects of repeated restraint stress on excitatory synaptic transmission and long-term potentiation (LTP) in the rat frontal cortex.Methods The effects of restraint stress lasting for 10 min, repeated twice daily for 3 consecutive days were studied ex vivo in the rat frontal cortex slices prepared 24 h after the last stress session. Rats received intraperitoneal injections of interleukin-1β antibody. In a separate experimental group, rats received injections of IL-1β. Field potentials were recorded in the cortical layer II/III.ResultsIn slices originating from stressed animals, the amplitude of field potentials was increased. Consistent with the previous studies, restraint stress resulted in a reduced magnitude of LTP. Similar effects were evident after administration of IL-1β. Stress-induced modifications of the glutamatergic transmission and synaptic plasticity were prevented by interleukin-1β antibody, which was administered 15 min before each restraint session.Conclusions These data point to an involvement of peripherally produced IL-1β in mediating the influence of repeated restraint stress on the functions of the frontal cortex.
    Pharmacological reports: PR 09/2014; 67(1). DOI:10.1016/j.pharep.2014.08.011 · 2.17 Impact Factor