Estrogens and progestins enhance spatial learning of intact and ovariectomized rats in the object placement task

Frye, Cheryl A.; Duffy, Caryn K.; Walf, Alicia A.

doi:10.1016/j.nlm.2007.04.003

Cited by 216 publications

(242 citation statements)

References 78 publications

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“…While the effect of estradiol on false memories has not yet been directly examined in humans, recent animal studies have demonstrated improved object recognition memory in rats following estradiol treatment (e.g. Frye et al, 2007;Inagaki et al, 2010;Jacome et al, 2010). In contrast to previous studies investigating recognition performance, the present findings suggest that estradiol does not improve false recognition in humans in general.…”

Section: Estradiol Reduces False Recognition In Highly Schizotypal Wocontrasting

confidence: 99%

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women

Hodgetts

Hausmann

Weis

2015

Psychiatry Research

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(2015) 'High estradiol levels improve false memory rates and meta-memory in highly schizotypal women.', Psychiatry research., 229 (3). pp. 708-714. Further information on publisher's website:https://doi.org/10.1016/j.psychres. 2015.08.016 Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Psychiatry Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be re ected in this document. Changes may have been made to this work since it was submitted for publication. Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractOverconfidence in false memories is often found in patients with schizophrenia and healthy participants with high levels of schizotypy, indicating an impairment of meta-cognition within the memory domain. In general, cognitive control is suggested to be modulated by natural fluctuations in estrogen. However, whether estrogen exerts beneficial effects on metamemory has not yet been investigated. The present study sought to provide evidence that high levels of schizotypy are associated with increased false memory rates and overconfidence in false memories, and that these processes may be modulated by natural differences in estradiol levels. Using the Deese-Roediger-McDermott paradigm, it was found that highly schizotypal participants with high estradiol produced significantly fewer false memories than those with low estradiol. No such difference was found within the low schizotypy participants. Highly schizotypal participants with high estradiol were also less confident in their false memories than those with low estradiol; low schizotypy participants with high estradiol were more confident. However, these differences only approached significance. These findings suggest that the beneficial effect of estradiol on memory and meta-memory observed in healthy participants is specific to highly schizotypal individuals and might be related to individual differences in baseline dopaminergic activity.

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Section: Estradiol Reduces False Recognition In Highly Schizotypal Wocontrasting

confidence: 99%

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women

Hodgetts

Hausmann

Weis

2015

Psychiatry Research

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“…Interestingly, cell proliferation was reduced with coadministration of DPN and PPT [88]. Furthermore, ERα in the hippocampus has been suggested to influence neuronal morphology by stimulating dendritic branching [89], whereas spatial, hippocampus-dependent learning has been shown to be mediated by both ERα [90][91] and ERβ [82,[92][93].…”

Section: The Role Of Erα (And Erβ) For Functional Effects Of Estogensmentioning

confidence: 99%

Rapid and estrogen receptor beta mediated actions in the hippocampus mediate some functional effects of estrogen

Walf

Frye

2008

Steroids

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The steroid hormone, estradiol (E 2 ), has numerous targets in the central nervous system, including the hippocampus, which plays a key role in cognition and affective behavior. This review focuses on our evidence from studies in rodents that E 2 has diverse mechanisms in the hippocampus for its functional effects E 2 has rapid, membrane-mediated effects in the hippocampus to enhance cognitive performance. Administration of E 2 to the hippocampus of rats for 10 minutes following training enhances performance in a hippocampus-mediated task. Increased cell firing in the hippocampus occurs within this short time frame. Furthermore, administration of free E 2 or an E 2 conjugate, E 2 :bovine serum albumin (BSA), to the hippocampus produces similar performance-enhancing effects in this task, suggesting that E 2 has membrane actions in the hippocampus for these effects. Further evidence that E 2 has rapid, membrane-mediated effects is that co-administration of E 2 and inhibitors of mitogen activated protein kinase (MAPK), rather than intracellular E 2 receptors (ERs) or protein synthesis, attenuate the enhancing effects of E 2 in this task. Despite these data that demonstrate E 2 can have rapid and/or membrane-mediated effects in the hippocampus, there is clear evidence to suggest that intracellular ERs, particularly the β (rather than α) isoform of ERs, may be important targets for E 2 's functional effects for hippocampal processes. Administration of ligands that are specific for ERβ, but not ERα, have enhancing effects on hippocampal processes similar to that of E 2 (which has similar affinity for ERα and ERβ). These effects are attenuated when ERβ expression is knocked down in transgenic models or with central administration of antisense oligonucleotides. Thus, there may be a convergence of E 2 's actions through rapid, membranemediated effects and intracellular ERs and in the hippocampus for these functional effects.

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“…Although many studies showed that OVX is associated with poorer behavioral and cognitive performance, including tasks considered relevant to schizophrenia such as social interaction and object recognition (Barnes et al, 2006;Frye, 2001;Frye et al, 2006bFrye et al, , 2007Frye and Rhodes, 2006a;Paris and Frye, 2008), the study of the estrogen hypothesis using animal models of schizophrenia has been limited. Some support derives from studies showing that estrogen affects prepulse inhibition (PPI) (Gogos et al, 2009;Gogos and Van den Buuse, 2004;Koch, 1998;Vaillancourt et al, 2002;Van den Buuse and Eikelis, 2001), a measure of sensorimotor gating whose disruption is considered to model sensorimotor deficits in schizophrenia, as well as the response to the pro-psychotic drugs amphetamine and cocaine (Becker and Beer, 1986;Becker and Rudick, 1999;Earley and Leonard, 1978;Gibbs et al, 1998;Naik et al, 1978;Segarra et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Contrasting Effects of Increased and Decreased Dopamine Transmission on Latent Inhibition in Ovariectomized Rats and Their Modulation by 17β-Estradiol: An Animal Model of Menopausal Psychosis?

Arad

Weiner

2010

Neuropsychopharmacol

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Women with schizophrenia have later onset and better response to antipsychotic drugs (APDs) than men during reproductive years, but the menopausal period is associated with increased symptom severity and reduced treatment response. Estrogen replacement therapy has been suggested as beneficial but clinical data are inconsistent. Latent inhibition (LI), the capacity to ignore irrelevant stimuli, is a measure of selective attention that is disrupted in acute schizophrenia patients and in rats and humans treated with the psychosisinducing drug amphetamine and can be reversed by typical and atypical APDs. Here we used amphetamine (1 mg/kg)-induced disrupted LI in ovariectomized rats to model low levels of estrogen along with hyperfunction of the dopaminergic system that may be occurring in menopausal psychosis, and tested the efficacy of APDs and estrogen in reversing disrupted LI. 17b-Estradiol (50, 150 mg/kg), clozapine (atypical APD; 5, 10 mg/kg), and haloperidol (typical APD; 0.1, 0.3 mg/kg) effectively reversed amphetamine-induced LI disruption in sham rats, but were much less effective in ovariectomized rats; 17b-estradiol and clozapine were effective only at high doses (150 mg/kg and 10 mg/kg, respectively), whereas haloperidol failed at both doses. Haloperidol and clozapine regained efficacy if coadministered with 17b-estradiol (50 mg/kg, an ineffective dose). Reduced sensitivity to dopamine (DA) blockade coupled with spared/potentiated sensitivity to DA stimulation after ovariectomy may provide a novel model recapitulating the combination of increased vulnerability to psychosis with reduced response to APD treatment in female patients during menopause. In addition, our data show that 17b-estradiol exerts antipsychotic activity.

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Estrogens and progestins enhance spatial learning of intact and ovariectomized rats in the object placement task

Cited by 216 publications

References 78 publications

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women

Rapid and estrogen receptor beta mediated actions in the hippocampus mediate some functional effects of estrogen

Contrasting Effects of Increased and Decreased Dopamine Transmission on Latent Inhibition in Ovariectomized Rats and Their Modulation by 17β-Estradiol: An Animal Model of Menopausal Psychosis?

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