Laboratory-induced stress produces elevations in cortisol and deficits in memory, especially when stress is induced immediately before retrieval of emotionally valent stimuli. Sex and sex steroids appear to influence these stress-induced outcomes, though no study has directly compared the effects of laboratory-induced stress on cortisol and emotional retrieval across the menstrual cycle. We examined the effect of psychosocial stress on cortisol responsivity and emotional retrieval in women tested during either the follicular phase (low estradiol and progesterone) or the luteal phase (higher estradiol and progesterone). Forty women (50%White; age 18–40 years) participated in the study; 20 completed the task during the luteal phase and 20 during the follicular phase. Psychosocial stress was induced with the Trier Social Stress Test (TSST). On the day before the TSST, participants learned two lists of word pairs to 100% criterion. The next day, participants recalled one list after the control condition and the other after the TSST. Women in the follicular phase, but not the luteal phase, demonstrated a significant cortisol response to the TSST. There was a stress-induced decrease in emotional retrieval following the TSST, but this effect was not modified by menstrual phase. However, regression and correlational analyses showed that individual differences in stress-induced cortisol levels were associated with impaired emotional retrieval in the follicular phase only. The present findings indicate that cortisol responsivity and the impairing effects of cortisol on emotional memory are lower when levels of estradiol and progesterone are high compared to when levels are low.
Alcohol excitation of the ventral tegmental area (VTA) is important in neurobiological processes related to the development of alcoholism. The ionotropic receptors on VTA neurons that mediate ethanol-induced excitation have not been identified. Quinidine blocks ethanol excitation of VTA neurons, and blockade of two-pore potassium channels is among the actions of quinidine. Therefore two-pore potassium channels in the VTA may be potential targets for the action of ethanol. Here, we explored whether ethanol activation of VTA neurons is mediated by the twopore potassium channel KCNK13. Extracellular recordings of the response of VTA neurons to ethanol were performed in combination with knockdown of Kcnk13 using a short hairpin RNA (shRNA) in C57BL/6J mice. Real-time PCR and immunohistochemistry were used to examine expression of this channel in the VTA. Finally, the role of KCNK13 in binge-like drinking was examined in the drinking in the dark test after knockdown of the channel. Kcnk13 expression in the VTA was increased by acute ethanol exposure. Ethanol-induced excitation of VTA neurons was selectively reduced by shRNA targeting Kcnk13. Importantly, knockdown of Kcnk13 in the VTA resulted in increased alcohol drinking. These results are consistent with the idea that ethanol stimulates VTA neurons at least in part by inhibiting KCNK13, a specific two-pore potassium channel, and that KCNK13 can control both VTA neuronal activity and binge drinking. KCNK13 is a novel alcohol-sensitive molecular target and may be amenable to the development of pharmacotherapies for alcoholism treatment.
BackgroundChronic alcohol exposure can alter glucocorticoid receptor (GR) function in some brain areas that promotes escalated and compulsive‐like alcohol intake. GR antagonism can prevent dependence‐induced escalation in drinking, but very little is known about the role of GR in regulating high‐risk nondependent alcohol intake. Here, we investigate the role of GR in regulating binge‐like drinking and aversive responses to alcohol in the High Drinking in the Dark (HDID‐1) mice, which have been selectively bred for high blood ethanol (EtOH) concentrations (BECs) in the Drinking in the Dark (DID) test, and in their founder line, the HS/NPT.MethodsIn separate experiments, male and female HDID‐1 mice were administered one of several compounds that inhibited GR or its negative regulator, FKBP51 (mifepristone [12.5, 25, 50, 100 mg/kg], CORT113176 [20, 40, 80 mg/kg], and SAFit2 [10, 20, 40 mg/kg]) during a 2‐day DID task. EtOH consumption and BECs were measured. EtOH conditioned taste and place aversion (CTA and CPA, respectively) were measured in separate HDID‐1 mice after mifepristone administration to assess GR’s role in regulating the conditioned aversive effects of EtOH. Lastly, HS/NPT mice were administered CORT113176 during DID to assess whether dissimilar effects from those of HDID‐1 would be observed, which could suggest that selective breeding had altered sensitivity to the effects of GR antagonism on binge‐like drinking.ResultsGR antagonism (with both mifepristone and CORT113176) selectively reduced binge‐like EtOH intake and BECs in the HDID‐1 mice, while inhibition of FKBP51 did not alter intake or BECs. In contrast, GR antagonism had no effect on EtOH intake or BECs in the HS/NPT mice. Although HDID‐1 mice exhibit attenuated EtOH CTA, mifepristone administration did not enhance the aversive effects of EtOH in either a CTA or CPA task.ConclusionThese data suggest that the selection process increased sensitivity to GR antagonism on EtOH intake in the HDID‐1 mice, and support a role for the GR as a genetic risk factor for high‐risk alcohol intake.
Two independent lines of High Drinking in the Dark (HDID-1, HDID-2) mice have been bred to reach high blood alcohol levels after a short period of binge-like ethanol drinking. Male mice of both lines were shown to have reduced sensitivity to develop a taste aversion to a novel flavor conditioned by ethanol injections as compared with their unselected HS/NPT founder stock. We have subsequently developed inbred variants of each line. The current experiments established that reduced ethanol-conditioned taste aversion is also seen in the inbred variants, in both males and females. In other experiments, we asked whether HDID mice would ingest sufficient doses of ethanol to lead to a conditioned taste aversion upon retest. Different manipulations were used to elevate consumption of ethanol on initial exposure. Access to increased ethanol concentrations, to multiple tubes of ethanol, and fluid restriction to increase thirst motivation all enhanced initial drinking of ethanol. Each condition led to reduced intake the next day, consistent with a mild conditioned taste aversion. These experiments support the conclusion that one reason contributing to the willingness of HDID mice to drink to the point of intoxication is a genetic insensitivity to the aversive effects of ethanol.
Despite the availability of effective antiretroviral therapies, cognitive impairment (CI) remains prevalent in HIV-infected (HIV+) individuals. Evidence from primarily cross-sectional studies, in predominantly male samples implicates monocyte and macrophage-driven inflammatory processes linked to HIV-associated CI. Thus, peripheral systemic inflammatory markers may be clinically useful biomarkers in tracking HIV-associated CI. Given sex differences in immune function, we focused here on whether mean and intraindividual variability in inflammatory markers predicted CI in HIV+ and HIV− women. Seventy-two HIV+ (36 with CI) and 58 HIV− (29 with CI) propensity-matched women participating in the Women’s Interagency HIV Study completed a neuropsychological battery once between 2009–2011 and performance was used to determine CI status. Analysis of 13 peripheral immune markers was conducted on stored biospecimens at 3 time points (7 and 3.5 years before neuropsychological data collection and concurrent with data collection). HIV+ women showed alterations in 8 immune markers compared to HIV− women. The strongest predictors of CI across HIV+ and HIV− women were lower mean soluble tumor necrosis factor receptor I (sTNFRI) levels, higher mean interleukin (IL)-6 levels, and greater variability in C-reactive protein (CRP) and matrix metalloproteinase (MMP)-9 (p’s<0.05). Stratified by HIV, the only significant predictor of CI was greater variability in CRP for both HIV+ and HIV− women (p’s<0.05). This variability predicted lower executive function, attention/working memory, and psychomotor speed in HIV+ but only learning in HIV− women (p’s<0.05). Intraindividual variability in CRP levels over time may be a good predictor of CI in predominately minority low socioeconomic status midlife women.
Oral contraceptive (OC) users typically show a blunted or no cortisol response to psychosocial stress. Although most OC regimens include both an inactive (dummy) and active pill phase, studies have not systematically investigated cortisol responses during these pill phases. Further, high levels of cortisol following a stressor diminish retrieval of emotional material, but the effects of stress on memory among OC users are poorly understood. We examined the effects of a psychosocial stressor, the Trier Social Stress Test, versus a control condition on cortisol responsivity and emotional memory retrieval in women tested either during their active (n=18) or inactive pill phase (n = 21). In secondary analyses, we quantitatively compared OC users to normally cycling women and showed a significant lack of cortisol response during both active and inactive pill phase. Emotional recall did not differ between active and inactive pill phases. Stress differentially diminished recall of negative words compared to positive or neutral words, but cortisol levels were unrelated to memory performance. These findings indicate that OC users have distinct cortisol and memory responses to stress that are similar between the active and inactive pill phases.
Objectives In a pilot randomized clinical trial of active stellate ganglion blockade (SGB) versus sham control, SGB significantly reduced the frequency of reported moderate to severe vasomotor symptoms (VMS) and the frequency of physiologic VMS measured using ambulatory skin conductance monitors. Here we examine secondary effects of SGB on verbal learning and memory. Study Design In a randomized, sham-controlled study, 36 women met eligibility criteria for cognitive assessments, of whom 17 were randomized to receive fluoroscopy-guided SGB and 19 to sham control. Main Outcome Measures At baseline and three months post-treatment, women completed tests of verbal learning and memory (primary outcome) and other cognitive measures and also wore an ambulatory monitor for 24 hours to measure physiologic VMS and VMS reported in real time. Results Verbal learning improved following active SGB (p<0.05) but not sham treatment; however, the interaction between group and time was not significant (p values 0.13-0.20). Two secondary cognitive measures improved only in the sham group. Improvements in physiologic VMS correlated significantly with improvements in verbal learning (r=0.51, p<0.05). Conclusions SGB might confer benefits to memory in relation to the magnitude of improvement in physiologic VMS. Broadly these findings suggest a possible link between physiologic VMS and memory problems in midlife women.
LIM-domain only 3 (LMO3) is a transcriptional regulator involved in central nervous system development and neuroblastoma. Our previous studies implicated a potential role for LMO3 in regulating ethanol sensitivity and consumption. Here, we examined behavioral responses to ethanol in a line of Lmo3 null (Lmo3Z) mice, utilizing the ethanol-induced loss-of-righting-reflex (LORR) test, 2-bottle choice ethanol consumption, and the drinking in the dark (DID) test, which models binge-like ethanol consumption. We found that Lmo3Z mice exhibited increased sedation time in response to ethanol in the LORR test and drank significantly more ethanol in the DID test compared to their wild-type counterparts, but showed no differences in 2-bottle choice ethanol consumption. To explore where LMO3 may be acting in the brain to produce an ethanol phenotype, we also examined reporter gene (β-galactosidase, β-gal) expression in heterozygous Lmo3Z mice and found strong expression in subcortical areas, particularly in those areas implicated in drug abuse, including the nucleus accumbens (Acb), cortex, hippocampus, and amygdala. We also examined Lmo3 expression in the brains of wild-type mice who had undergone the DID test and found a negative correlation between Lmo3 expression in the Acb and the amount of ethanol consumed, consistent with the increased binge-like drinking observed in Lmo3Z mice. These results support a role for LMO3 in regulating behavioral responses to ethanol, potentially through its actions in the Acb.
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