Changes in central GABAergic function following acute and repeated stress

Losada, Matilde E. Otero

doi:10.1111/j.1476-5381.1988.tb10302.x

Cited by 55 publications

(22 citation statements)

References 35 publications

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“…Several lines of evidence point on this direction. On one hand, stress exposure was shown to enhance the release of excitatory neurotransmitters (such as glutamate, dopamine, norepinephrine, or acetylcholine) in the hippocampus and PFC (Finlay et al, 1995; Mark et al, 1996; Feenstra, 2000; Moghaddam, 2002; Dazzi et al, 2004); on the other hand, it is known that GABAergic activity is reduced after stress exposure in these brain regions (Otero Losada, 1988; Hasler et al, 2010). Interestingly, once the increase in PSD is established in the vHIP, the changes in the mPFC might also be due to an augmented afferent excitatory input; in this case an early increase in the activation of hippocampal neurons could lead consequently to overactivation of monosynaptically connected (Jay and Witter, 1991; Thierry et al, 2000; Tierney et al, 2004) neurons in the mPFC.…”

Section: Discussionmentioning

confidence: 99%

Chronic stress disrupts neural coherence between cortico-limbic structures

Oliveira¹,

Dias²,

Correia³

et al. 2013

Front. Neural Circuits

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Chronic stress impairs cognitive function, namely on tasks that rely on the integrity of cortico-limbic networks. To unravel the functional impact of progressive stress in cortico-limbic networks we measured neural activity and spectral coherences between the ventral hippocampus (vHIP) and the medial prefrontal cortex (mPFC) in rats subjected to short term stress (STS) and chronic unpredictable stress (CUS). CUS exposure consistently disrupted the spectral coherence between both areas for a wide range of frequencies, whereas STS exposure failed to trigger such effect. The chronic stress-induced coherence decrease correlated inversely with the vHIP power spectrum, but not with the mPFC power spectrum, which supports the view that hippocampal dysfunction is the primary event after stress exposure. Importantly, we additionally show that the variations in vHIP-to-mPFC coherence and power spectrum in the vHIP correlated with stress-induced behavioral deficits in a spatial reference memory task. Altogether, these findings result in an innovative readout to measure, and follow, the functional events that underlie the stress-induced reference memory impairments.

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Section: Discussionmentioning

confidence: 99%

Chronic stress disrupts neural coherence between cortico-limbic structures

Oliveira¹,

Dias²,

Correia³

et al. 2013

Front. Neural Circuits

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“…Previous work has shown that the nucleus accumbens and amygdala play prominent roles in modulation of the interoceptive effects of alcohol (Besheer et al 2003, 2009; Hodge and Aiken 1996; Hodge and Cox 1998). Thus, decreased sensitivity to the interoceptive effects of alcohol following repeated CORT exposure may be related, in part, to maladaptive changes (i.e., neurochemical, transcription, and signaling) within these limbic brain regions (Buffalari and Grace 2009; Makino et al 1994; Morales-Medina et al 2009; Otero Losada 1988; Perrotti et al 2004; Wang et al 2010). Therefore, it will be of interest for future work to determine the functional neurobiological mechanism underlying the related decreased sensitivity to the interoceptive effects of alcohol.…”

Section: Discussionmentioning

confidence: 99%

The effects of repeated corticosterone exposure on the interoceptive effects of alcohol in rats

et al. 2011

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Rationale and objective Repeated and/or heightened elevations in glucocorticoids (e.g., repeated stress) can promote escalated drug-taking behaviors and induce compromised HPA axis function. Given that interoceptive/subjective drug cues are a fundamental factor in drug-taking behavior, we sought to determine the effects of exposure to repeated elevations in the glucocorticoid corticosterone (CORT) on the interoceptive effects of alcohol in rats using drug discrimination techniques. Methods Male Long Evans rats trained to discriminate alcohol (1 g/kg, IG) vs. water were exposed to CORT (300 μg/ml) in the home cage drinking water for 7 days. The interoceptive effects of experimenter- and self-administered alcohol were assessed and HPA axis function was determined. Results The interoceptive effects of experimenter- and self-administered alcohol were blunted following CORT. Control experiments determined that this decreased sensitivity was unrelated to discrimination performance impairments or decreased CORT levels at the time of testing and was dependent on repeated CORT exposure. Susceptibility to compromised HPA axis function following CORT exposure was suggested by an altered pattern of CORT secretion and blunted CORT response following injection of the synthetic glucocorticoid dexamethasone. Conclusions These findings present a possible behavioral mechanism for escalated alcohol drinking during episodes of heightened elevations in glucocorticoids (e.g., stress). That is, during these episodes, individuals may consume more alcohol to achieve the desired interoceptive effects. Understanding these behavioral mechanisms may lead to a better understanding of factors that promote alcoholism and alcohol abuse in at risk populations.

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“…Taken together, it is suggested that the observed decrease in GABA concentration is likely related to a rapid down-regulation of glutamate decarboxylase associated with acute psychological stress. Glutamate decarboxylase activity and GABA concentrations are modulated during a variety of physiological and pathological conditions, including acute stress (6, 13). Previous kinetic studies performed on both animals and humans have also shown that GABA undergoes rapid turnover (34–36).…”

Section: Discussionmentioning

confidence: 99%

“…Prefrontal GABA concentrations were determined using a recently developed MRS method with a 3 Tesla General Electric magnetic resonance imaging (MRI) scanner (General Electric, Milwaukee) and a homogeneous resonator coil that allowed for reliable determination of GABA levels with a temporal resolution of 8 minutes. Since stress reduces GABA levels in the medial prefrontal cortex in rat models (6), we hypothesized that the prefrontal GABA concentration would decrease following acute psychological stress in humans.…”

mentioning

confidence: 99%

Effect of Acute Psychological Stress on Prefrontal GABA Concentration Determined by Proton Magnetic Resonance Spectroscopy

Hasler¹,

Veen²,

Grillon³

et al. 2010

AJP

103

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Objective Impaired function of the central gamma-aminobutyric acid (GABA) system, which provides the brain’s major inhibitory pathways, is thought to play an important role in the pathophysiology of anxiety disorders. The effect of acute psychological stress on the human GABA-ergic system is still unknown, however. The purpose of this study was to determine the effect of acute stress on prefrontal GABA levels. Method A recently developed noninvasive magnetic resonance spectroscopy method was used to measure changes in the GABA concentration of the prefrontal cortex in 10 healthy human subjects during a threat-of-shock condition and during a safe condition (two sessions on different days). The main outcome measure was the mean GABA concentration within a 3×3×2-cm3 voxel selected from the medial prefrontal cortex. Results Prefrontal GABA decreased by approximately 18% in the threat-of-shock condition relative to the safe condition. This reduction was specific to GABA, since the concentrations of N-acetyl-aspartate, choline-containing compounds, and glutamate/glutamine levels obtained in the same spectra did not change significantly. Conclusions This result appeared compatible with evidence from preclinical studies in rodents, which showed rapid presynaptic down-regulation of GABA-ergic neurotransmission in response to acute psychological stress. The molecular mechanism and functional significance of this reduced inhibitory effect of acute psychological stress in relation to impaired GABA-ergic function in anxiety disorders merit further investigation.

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Changes in central GABAergic function following acute and repeated stress

Cited by 55 publications

References 35 publications

Chronic stress disrupts neural coherence between cortico-limbic structures

Chronic stress disrupts neural coherence between cortico-limbic structures

The effects of repeated corticosterone exposure on the interoceptive effects of alcohol in rats

Effect of Acute Psychological Stress on Prefrontal GABA Concentration Determined by Proton Magnetic Resonance Spectroscopy

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