Low levels of estradiol are associated with elevated conditioned responding during fear extinction and with intrusive memories in daily life

Estradiol levels are differentially associated with pulse wave velocity in trauma-exposed premenopausal women with and without PTSD

Arterial stiffness is a well-known risk factor for cardiovascular disease. Although estradiol (E2) is known to be cardioprotective, the available data point to a growing cardiovascular disease risk in women before menopause due to posttraumatic stress disorder (PTSD). The present study aimed to investigate the effects of E2 on arterial compliance in trauma-exposed premenopausal women, with and without a clinical diagnosis of PTSD. We hypothesized that E2 will be differentially associated with pulse wave velocity (PWV) in women with PTSD (PTSD+, n = 45) and without PTSD (PTSD-, n = 47). Estradiol and PWV were measured during two separate study visits. Serum E2 levels were measured via the quantitative sandwich enzyme-linked immunoassay technique (ELISA) and log-transformed due to non-normal distribution. Carotid to femoral applanation tonometry was used to measure PWV. Our analyses revealed an overall weak and nonsignificant correlation between E2 and PWV (r = -0.119, P = 0.350). However, when examining each group, we found a negative association between E2 and PWV in PTSD- (r = -0.466, P = 0.004). In contrast, we found an unexpected positive association between E2 levels and PWV in PTSD+ (r = 0.360, P = 0.037). Furthermore, a multiple linear regression revealed that E2 was predictive of PWV in PTSD- only, even after accounting for the phase of the menstrual cycle, age, body mass index, diastolic blood pressure, and PTSD symptom severity (R2 = 0.670, P = 0.005). Interestingly, we also found lower levels of E2 in PTSD+ than PTSD- (1.4 ± 0.4 vs. 1.6 ± 0.4 pg/mL, P = 0.022). These findings suggest that PTSD may inhibit the protective effects of E2 on arterial compliance in women before menopause.NEW & NOTEWORTHY In trauma-exposed premenopausal women, we found that serum estradiol (E2) was a predictor of pulse wave velocity (PWV) only in the absence of a posttraumatic stress disorder (PTSD) diagnosis, even after accounting for the phase of the menstrual cycle, age, body mass index, diastolic blood pressure, and PTSD symptom severity. Moreover, E2 levels were lower in women with PTSD than in those without PTSD. We collected E2 and PWV during two separate visits and controlled for the menstrual cycle phase in our analyses.

Contraceptives and conditioning: Different profiles of fear and expectancy ratings during fear conditioning and extinction according to menstrual cycle phase and hormonal contraceptive use

Hormonal contraceptives (HC) such as the oral contraceptive pill (OC) and the hormonal intrauterine device (IUD) have been associated with depressed mood, but research on their role in anxiety is scarce and inconsistent. In a fear acquisition and extinction paradigm, self-report fear, expectancy, and skin conductance responses (SCR) were assessed, along with sex hormone levels. Naturally cycling (NC) participants were measured during the mid-follicular and mid-luteal phases (within subjects, n = 26) and compared with OC (n = 36) and IUD (n = 25) users. IUD users and -participants in the luteal phase showed overall reduced self-reported CS+ vs CS- differentiation compared to the follicular phase and OC use (which both reflect relatively low levels of endogenous gonadal hormones). This overall reduced differentiation in self-reported fear in the luteal phase was attributed to a generalization of fear from CS+ to CS-. NC-individuals with high premenstrual syndrome (PMS) ratings had higher overall fear ratings regardless of cycle phase. For SCR, hormonal status effects were restricted to specific experimental phases during acquisition. SCR to the CS+ was higher at the end of acquisition in the luteal phase compared to the follicular phase, and in OC users during early acquisition (compared to the follicular phase) and mid acquisition (compared to the IUD group). There were no direct associations with sex hormone levels. These findings demonstrate the impact of menstrual cycle and HC use on fear learning and highlight the need for further research that considers different outcome measures across a wide array of menstrual cycle and HC-related characteristics.

A systematic review on the bidirectional relationship between trauma-related psychopathology and reproductive aging

Objective

Natural variation in ovarian steroid hormones across the female lifespan contributes to an increased risk for depressive and posttraumatic stress disorder (PTSD) symptoms in women. However, minimal work has focused on understanding the impacts of reproductive aging on the brain and behavioral health of trauma-exposed women. This systematic review examines the bidirectional relationship between trauma-related psychopathology and reproductive aging.

Method

Following PRISMA guidelines, a systematic review of PubMed, PsychInfo, and Medline databases was undertaken to identify controlled studies on how trauma history impacts psychopathology and menopause symptoms during reproductive aging.

Results

Twenty-one studies met the eligibility criteria, with only four utilizing the gold standard STRAW+ 10 criteria for defining reproductive aging stages. The peri and postmenopausal periods appear to be particularly vulnerable phases for individuals with trauma exposure. Menopause symptoms and trauma-related psychopathology symptom severity increase during reproductive aging with increases in the degree of trauma exposure. However, mechanistic insights that may explain this interaction are currently neglected in this area of research.

Conclusion

There is a significant lack of understanding regarding how reproductive aging and its related neuroendocrine changes impact the brain to influence PTSD and depression symptoms related to trauma exposure. This lack of basic understanding impedes the ability to identify, assess, and treat PTSD and depressive symptoms in trauma-exposed women most effectively, and mitigate the long-term consequences of these behavioral health symptoms on morbidity and mortality in aging women.

Understanding sex differences in extinction retention: Pre-extinction stress and sex hormone status

Difficulties in fear regulation can sometimes result in maladaptive fear responses. To better understand how to improve fear regulation, it is important to determine how known factors, such as sex hormone status and stress, might interact to influence fear memory. Research has shown that women with high estradiol levels (mid-cycle) and men exhibit better extinction retention compared to women with low estradiol levels (women in the early follicular cycle or using oral contraceptives). Stress has also been demonstrated to affect both the learning and retention of extinction. Despite documented interactions between stress and sex hormones, their combined effects have not been thoroughly studied. This study aims to examine the impact of stress as a function of sex hormone status on extinction learning and retention. A total of 168 non-clinical participants were studied, including men (n = 46), women using oral contraceptives (n = 38), women in the early follicular phase (n = 40), and women in mid-cycle (n = 44). On Day 1, fear acquisition training was performed. On day 2, prior to extinction training, half of the participants were exposed to a psychosocial stressor, while the other half performed a non-stressful control task. On day 3, extinction retention was tested. Fear was quantified using skin conductance responses, while stress hormones were quantified through saliva samples. Exposure to stress prior to extinction training did not affect extinction learning, regardless of sex hormone status. In contrast, pre-extinction stress exposure had different effects on extinction retention depending on hormone status. Stressed men showed impairment in extinction retention compared to controls, while the experimental condition had no effect on naturally cycling women. Regardless of stress exposure, early follicular women exhibited a deficit in fear regulation, while mid-cycle women showed effective fear regulation. Among women using oral contraceptives, the stress group demonstrated better extinction retention compared to the control group. These results demonstrate the importance of considering sex hormone status and stress exposure during extinction learning, as both components may modulate extinction retention. These results could help identifying hormonal conditions that may enhance the effectiveness of extinction-based psychological therapies used in the treatment of fear-related disorders.

Inflammatory injury induces pain sensitization that is expressed beyond the site of injury in male (and not in female) mice

Pain is a crucial protective mechanism for the body. It alerts us to potential tissue damage or injury and promotes the avoidance of harmful stimuli. Injury-induced inflammation and tissue damage lead to pain sensitization, which amplifies responses to subsequent noxious stimuli even after an initial primary injury has recovered. This phenomenon, commonly referred to as hyperalgesic priming, was investigated in male and female mice to determine whether it is specific to the site of previous injury. We used 10μl of 50 % Freund's complete adjuvant (CFA) administered to the left hind paw as a model of peripheral injury. Both male and female mice exhibited robust site-specific mechanical hypersensitivity after CFA, which resolved within one-week post-injection. After injury resolution, only male CFA-primed mice showed enhanced and prolonged mechanical sensitivity in response to a chemical challenge or a single 0.5 mA electric footshock. Among CFA-primed male mice, shock-induced mechanical hypersensitivity was expressed in both the left (previously injured) and the right (uninjured) hind paws, suggesting a pivotal role for altered centralized processes in the expression of pain sensitization. These findings indicate that pain history regulates sensory responses to subsequent mechanical and chemical pain stimuli in a sex-specific manner-foot-shock-induced hyperalgesic priming expression among male mice generalized beyond the initial injury site.

An investigation of the role of estradiol in fear reduction during a single session of exposure therapy

Research suggests that estradiol may moderate fear extinction. It is unclear whether these results generalize to exposure therapy. The aim of the current study was to determine whether estradiol moderates outcomes in exposure therapy among women with anxiety disorders. Participants were 35 women with a primary diagnosis of an anxiety disorder who participated in the study as part of routine care at an anxiety specialty clinic. Endogenous estradiol was assessed via saliva. They provided subjective distress ratings before (pre) and after (post) an exposure session, as well as after a brief delay (recall). Contrary to predictions, there were no significant differences in exposure outcomes between the high and low estradiol groups. However, among participants with primary obsessive-compulsive disorder (OCD), results were partially consistent with the hypotheses. Women with lower estradiol initially demonstrated more improvement in subjective distress from pre- to post-exposure, but after the delay, significantly greater distress (attenuated extinction recall). Results suggest that women with lower estradiol may respond less favorably to exposure therapy for OCD relative to women with higher estradiol. These findings await replication in larger samples with longer recall delays. Should replication occur, these results may inform the use of estradiol to augment exposure therapy.

Cannabidiol ameliorates PTSD-like symptoms by inhibiting neuroinflammation through its action on CB2 receptors in the brain of male mice

Post-traumatic stress disorder (PTSD) is a debilitating mental health disease related to traumatic experience, and its treatment outcomes are unsatisfactory. Accumulating research has indicated that cannabidiol (CBD) exhibits anti-PTSD effects, however, the underlying mechanism of CBD remains inadequately investigated. Although many studies pertaining to PTSD have primarily focused on aberrations in neuronal functioning, the present study aimed to elucidate the involvement and functionality of microglia/macrophages in PTSD while also investigated the modulatory effects of CBD on neuroinflammation associated with this condition. We constructed a modified single-prolonged stress (SPS) mice PTSD model and verified the PTSD-related behaviors by various behavioral tests (contextual freezing test, elevated plus maze test, tail suspension test and novel object recognition test). We observed a significant upregulation of Iba-1 and alteration of microglial/macrophage morphology within the prefrontal cortex and hippocampus, but not the amygdala, two weeks after the PTSD-related stress, suggesting a persistent neuroinflammatory phenotype in the PTSD-modeled group. CBD (10 mg/kg, i.p.) inhibited all PTSD-related behaviors and reversed the alterations in both microglial/macrophage quantity and morphology when administered prior to behavioral assessments. We further found increased pro-inflammatory factors, decreased PSD95 expression, and impaired synaptic density in the hippocampus of the modeled group, all of which were also restored by CBD treatment. CBD dramatically increased the level of anandamide, one of the endocannabinoids, and cannabinoid type 2 receptors (CB2Rs) transcripts in the hippocampus compared with PTSD-modeled group. Importantly, we discovered the expression of CB2Rs mRNA in Arg-1-positive cells in vivo and found that the behavioral effects of CBD were diminished by CB2Rs antagonist AM630 (1 mg/kg, i.p.) and both the behavioral and molecular effects of CBD were abolished in CB2Rs knockout mice. These findings suggest that CBD would alleviate PTSD-like behaviors in mice by suppressing PTSD-related neuroinflammation and upregulation and activation of CB2Rs may serve as one of the underlying mechanisms for this therapeutic effect. The present study offers innovative experimental evidence supporting the utilization of CBD in PTSD treatment from the perspective of its regulation of neuroinflammation, and paves the way for leveraging the endocannabinoid system to regulate neuroinflammation as a potential therapeutic approach for psychiatric disorders.

The role of neurosteroids in posttraumatic stress disorder and alcohol use disorder: A review of 10 years of clinical literature and treatment implications

Rates of alcohol use disorder (AUD) are increasing in men and women and there are high rates of concurrent posttraumatic stress disorder (PTSD) and AUD. AUD and PTSD synergistically increase symptomatology and negatively affect treatment outcomes; however, there are very limited pharmacological treatments for PTSD/AUD. Neurosteroids have been implicated in the underlying neurobiological mechanisms of both PTSD and AUD and may be a target for treatment development. This review details the past ten years of research on pregnenolone, progesterone, allopregnanolone, pregnanolone, estradiol, testosterone and dehydroepiandrosterone/dehydroepiandrosterone-sulfate (DHEA/DHEA-S) in the context of PTSD and AUD, including examination of trauma/alcohol-related variables, such as stress-reactivity. Emerging evidence that exogenous pregnenolone, progesterone, and allopregnanolone may be promising, novel interventions is also discussed. Specific emphasis is placed on examining the application of sex as a biological variable in this body of literature, given that women are more susceptible to both PTSD diagnoses and stress-related alcohol consumption.

The impact of PTSD on associations between sex hormones and cardiovascular disease symptoms

Background: Women have twice the lifetime prevalence of posttraumatic stress disorder (PTSD) relative to men, and PTSD is a known risk factor for cardiovascular disease (CVD). Two sex hormones - estradiol and progesterone - have been found to impact both PTSD and CVD symptomatology, but the way in which sex hormones influence cardiovascular physiology among individuals with PTSD is not well understood.Objective: This study sought to clarify the association between sex hormones, PTSD, and CVD among trauma-exposed women.Method: Sixty-six trauma-exposed women (M age = 31.45, SD = 8.92) completed a clinical interview for PTSD and self-reported CVD symptoms; estradiol and progesterone were assayed from blood samples. The association between each sex hormone and CVD symptoms was analyzed, controlling for age, systolic blood pressure (BP), and diastolic BP.Results: Neither estradiol nor the PTSD-by-estradiol interaction was significantly associated with CVD symptoms. Higher progesterone and, relatedly, progesterone-to-estradiol ratio (PE ratio) were each significantly associated with greater CVD symptom severity, but only for individuals with lower relative PTSD severity.Conclusions: The findings indicate that PTSD moderates the relationship between progesterone and CVD symptoms, and further research is warranted to reconcile findings in existing literature regarding the direction of and mechanisms behind this relationship.

Effects of oral contraceptives on intrusive memories: a secondary analysis of two studies using the trauma film paradigm in healthy women

Background: Women are more likely to develop post-traumatic stress disorder (PTSD) than men. Recent research suggests an impact of oral contraceptive (OC) intake on PTSD and intrusive memories, a hallmark symptom of PTSD. Although a majority of women use OCs at some point in their lives, the effects on PTSD pathogenesis are only poorly understood.Objective: In the current paper, we aimed to investigate the impact of OC intake on the acquisition and consolidation of intrusive memories in healthy women after watching a trauma film paradigm.Methods: We performed a secondary analysis of a pooled dataset (N = 437) of two previously conducted and published studies investigating the effect of oxytocin on the development of intrusive memories.Results: Women taking OCs showed an attenuated decline of intrusive memories over time after having watched the trauma film compared to naturally cycling women (F(2.75, 1167) = 3.79, p = .03, η p 2  = .01).Conclusion: These findings indicate that the intake of OCs is associated with the development of intrusive memories after a trauma film paradigm. This indication emphasizes the need to further investigate the complex impact of OCs and gonadal hormones on fear learning processes and PTSD.

Dissociable role of the basolateral complex of the amygdala in the acquisition and extinction of conditioned fear following reproductive experience in female rats

In female rats and humans, reproductive experience (i.e., pregnancy) alters the behavioral, hormonal and molecular substrates of fear extinction. Here, we assessed whether the role of a central neural substrate of fear extinction, the basolateral amygdala (BLA), also changes following reproductive experience. Nulliparous (virgin) and primiparous (one prior pregnancy) female rats received infusions of the GABAA agonist, muscimol, to temporarily inactivate the BLA prior to fear conditioning or extinction training. In follow up experiments, the BLA was also inactivated immediately after extinction training. BLA inactivation impaired the acquisition and expression of conditioned fear in both nulliparous and primiparous rats. In nulliparous rats, BLA inactivation prior to or immediately after extinction training impaired extinction retention. In contrast, in primiparous rats, BLA inactivation prior to or immediately after extinction training did not impair extinction retention, despite suppressing freezing during extinction training. These results suggest that, consistent with past findings in males, the BLA is a central component of the neural circuitry of fear acquisition and its extinction in virgin female rats. However, after pregnancy, female rats no longer depend on the BLA to extinguish fear, despite requiring the BLA to acquire conditioned fear. Given that fear extinction forms the basis of exposure therapy for anxiety disorders in humans, the present findings may have clinical implications. To improve the efficacy of exposure therapy for anxiety disorders, we may need to target different mechanisms in females dependent on their reproductive history.

Association between perimenopausal age and greater posttraumatic stress disorder and depression symptoms in trauma-exposed women

OBJECTIVE

This study aimed to determine the relationship between stages of the menopause transition (premenopausal, perimenopausal, and postmenopausal) on symptoms of posttraumatic stress disorder (PTSD) and depression in trauma-exposed women.

METHODS

A cross-sectional study conducted between 2005 and 2017 recruited and enrolled an urban community sample (n = 6,093) from nonpsychiatric medical clinic waiting rooms of Grady Memorial Hospital, a public safety net hospital in Atlanta, Georgia. Participants were female, 18 to 65 years old, and predominantly Black/African American.

RESULTS

Of the 6,093 participants, 93.8% were Black/African American, 2.5% were White, and 3.8% were of all other races (Hispanic/Latino, Asian, multiracial). Participants younger than 40 years were categorized as premenopausal (n = 3,166), between 40 and 55 years of age were categorized as perimenopausal (n = 2,127), and older than 55 years were categorized as postmenopausal (n = 790). Menopause status was associated with total PTSD symptom severity ( F2,5416 = 9.61, P < 0.001), symptom severity within all three PTSD symptom clusters (avoidance/numbing symptoms: F2,5416 = 7.10, P < 0.001; intrusive symptoms: F2,5416 = 7.04, P < 0.001; hyperarousal symptoms: F2,5409 = 8.31, P < 0.001), and depression symptom severity ( F2,5148 = 11.4, P < 0.001). Compared with both premenopausal and postmenopausal women, perimenopausal women reported significantly worse total PTSD symptoms, symptoms in the hyperarousal cluster, and depressive symptoms.

CONCLUSIONS

The current cross-sectional data show that symptoms of PTSD and depression in women are associated with reproductive age, such that perimenopausal women show higher symptom severity than premenopausal and postmenopausal women. Future longitudinal studies can reveal how changes in hormones over the course of the menopause transition impact the symptoms, neurobiology, and psychophysiology of PTSD.

Transfer Effect of Cognitive Advantages in Visual Working Memory Capacity: Evidence from Elite Football Players

BACKGROUND

The research has indicated that elite football players demonstrate cognitive advantages in visual working memory capacity (VWMC); however, it remains unclear whether this effect transfers to other domains cognitive advantages.

OBJECT

This study investigated the VWMC differences between elite football players and novices, with a particular focus on cognitive advantages.

METHODS

Elite football players (specialized in football) and novices were selected to complete the VWMC test task under three different stimulus conditions, then the differences in the VWMCs of elite football players and novices were analyzed.

RESULTS

In comparison to novices, elite football players demonstrated cognitive advantages in VWMCs, along with a possible transfer effect. Additionally, the study showed that the reaction times among elite football players and novices differed, with elite players demonstrating shorter reaction times, which is a difference that was amplified as the number of stimuli increased.

CONCLUSION

The VWMCs of elite football players was better than that of novices under professional and meaningless conditions, which indicates that the VWMCs of elite football players has a transfer effect. Through further analysis of the reaction times cognitive advantages, it was found that there are significant differences between elite football players and novices when responding to the stimuli in both professional and meaningless conditions.

The role of estrogen receptor manipulation during traumatic stress on changes in emotional memory induced by traumatic stress

RATIONALE

Traumatic stress leads to persistent fear, which is a core feature of post-traumatic stress disorder (PTSD). Women are more likely than men to develop PTSD after trauma exposure, which suggests women are differentially sensitive to traumatic stress. However, it is unclear how this differential sensitivity manifests. Cyclical changes in vascular estrogen release could be a contributing factor where levels of vascular estrogens (and activation of estrogen receptors) at the time of traumatic stress alter the impact of traumatic stress.

METHODS

To examine this, we manipulated estrogen receptors at the time of stress and observed the effect this had on fear and extinction memory (within the single prolonged stress (SPS) paradigm) in female rats. In all experiments, freezing and darting were used to measure fear and extinction memory.

RESULTS

In Experiment 1, SPS enhanced freezing during extinction testing, and this effect was blocked by nuclear estrogen receptor antagonism prior to SPS. In Experiment 2, SPS decreased conditioned freezing during the acquisition and testing of extinction. Administration of 17β-estradiol altered freezing in control and SPS animals during the acquisition of extinction, but this treatment had no effect on freezing during the testing of extinction memory. In all experiments, darting was only observed to footshock onset during fear conditioning.

CONCLUSION

The results suggest multiple behaviors (or different behavioral paradigms) are needed to characterize the nature of traumatic stress effects on emotional memory in female rats and that nuclear estrogen receptor antagonism prior to SPS blocks SPS effects on emotional memory in female rats.

The Impacts of Sex Differences and Sex Hormones on Fear Extinction

Fear extinction memories are strongly modulated by sex and hormonal status, but the exact mechanisms are still being discovered. In humans, there are some basal and task-related features in which male and female individuals differ in fear conditioning paradigms. However, analyses considering the effects of sex hormones demonstrate a role for estradiol in fear extinction memory consolidation. Translational studies are taking advantage of the convergent findings between species to understand the brain structures implicated. Nevertheless, the human brain is complex and the transfer of these findings into the clinics remains a challenge. The promising advances in the field together with the standardization of fear extinction methodologies in humans will benefit the design of new personalized therapies.

The impact of hormonal contraceptives on anxiety treatments: From preclinical models to clinical settings

Exposure therapy is a central component of the first-line treatment for anxiety disorders, a common mental health condition that is twice as prevalent in women relative to men. A key underlying mechanism of exposure therapy is fear extinction, which is an active learning process supported by a neural circuitry that is highly regulated by ovarian hormones. This review synthesises research examining the impact of hormonal contraceptives on laboratory fear extinction tasks in female rats and women, and on exposure therapy in women with anxiety disorders. The evidence indicates that hormonal contraceptives have a detrimental impact on fear extinction and exposure therapy that is consistent across species, and from laboratory to clinical settings. Candidate pathways by which hormonal contraceptives impede fear extinction and exposure therapy include suppression of endogenous ovarian hormones and glucocorticoids, and downregulation of signalling pathways that support extinction learning. Key areas of focus for future research are discussed.

Estradiol during (analogue-)trauma: Risk- or protective factor for intrusive re-experiencing?

Intrusions, a key symptom of posttraumatic stress disorder (PTSD), can occur in the form of images but also as pain sensations. Similar to audiovisual intrusions, the frequency and persistence of pain intrusions varies greatly between individuals. In the current study, we examined whether peritraumatic circulating 17β-estradiol (E2) levels are a biologic factor associated with subsequent audiovisual (i.e., film) and pain intrusion development, and whether peritraumatic stress levels modulate this relationship. Forty-one free-cycling women participated in an ecologically informed trauma-pain-conditioning (TPC) paradigm, using trauma-films and pain as unconditioned stimuli. Independent variables were salivary peritraumatic E2 levels and stress indexed by salivary cortisol and self-reported state-anxiety during TPC. Outcomes were film- and pain-intrusions occurring during daily-life in the week following TPC and a Memory-Triggering-Task in response to conditioned stimuli 24 h after TPC. In the week after analogue-trauma, higher peritraumatic E2 levels were associated with a greater probability of experiencing film-intrusions in the beginning of the week, which switched to a lower probability toward the end of the week. This time-dependent relationship between E2 and film-intrusions only held for higher state-anxious women. In contrast, results indicated a consistent inverse relationship between peritraumatic E2 levels and pain-intrusions during daily-life and Memory-Triggering-Task. Together, these data suggest that higher peritraumatic E2 levels could be associated with lower long-term visual trauma intrusions, as well as lower pain-intrusions, and thereby possibly constitute a protective biologic factor for PTSD and potentially also for chronic pain.

PACAP-PAC1R modulates fear extinction via the ventromedial hypothalamus

Exposure to traumatic stress can lead to fear dysregulation, which has been associated with posttraumatic stress disorder (PTSD). Previous work showed that a polymorphism in the PACAP-PAC1R (pituitary adenylate cyclase-activating polypeptide) system is associated with PTSD risk in women, and PACAP (ADCYAP1)-PAC1R (ADCYAP1R1) are highly expressed in the hypothalamus. Here, we show that female mice subjected to acute stress immobilization (IMO) have fear extinction impairments related to Adcyap1 and Adcyap1r1 mRNA upregulation in the hypothalamus, PACAP-c-Fos downregulation in the Medial Amygdala (MeA), and PACAP-FosB/ΔFosB upregulation in the Ventromedial Hypothalamus dorsomedial part (VMHdm). DREADD-mediated inhibition of MeA neurons projecting to the VMHdm during IMO rescues both PACAP upregulation in VMHdm and the fear extinction impairment. We also found that women with the risk genotype of ADCYAP1R1 rs2267735 polymorphism have impaired fear extinction.

Estradiol, stress reactivity, and daily affective experiences in trauma-exposed women

OBJECTIVE

Women experience higher risk for PTSD following trauma compared with men. Fluctuations in ovarian hormones might contribute to this greater vulnerability, given that estradiol is associated with affect and stress reactivity. Our objective was to test the relations between menstrual cycle-related changes in estradiol, affect, stress reactivity, and trauma-related symptoms.

METHOD

We assessed trauma-related symptoms in ethnically diverse naturally cycling women with a history of trauma during a clinical interview. Participants also completed a 10-day ecological momentary assessment (EMA) that included lower- and higher-estradiol phases. We tested associations between estradiol and PTSD symptoms and stress reactivity to a trauma reminder using Spearman correlation and Wilcoxon rank-sum tests. We tested the effect of menstrual cycle day on daily affect using multilevel modeling.

RESULTS

Estradiol was negatively associated with symptom severity (rs = -.36), and participants in low- versus high-estradiol cycle phases at interview had higher sympathetic (r = .35) and lower hypothalamic-pituitary-adrenal axis (r = .41) reactivity. Across the EMA period, participants showed a decrease in daily PTSD symptoms (b = -.39), negative (b = -.11) and positive (b = -.24) affect, and variability in daily valence (b = -.07) and arousal (b = -.08), from the low- to high-estradiol phase.

CONCLUSIONS

Consistent with prior evidence of more aversive affective experiences in low-estradiol states, lower estradiol was associated with higher trauma-related symptoms. In addition, trauma-exposed women showed a discordant pattern of stress reactivity to a trauma reminder, higher daily symptoms, and greater affective lability in a low-estradiol phase. Given that our sample consisted of high-functioning trauma-exposed women, these results should be replicated in women with PTSD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Lonely in the Dark: Trauma Memory and Sex-Specific Dysregulation of Amygdala Reactivity to Fear Signals

Loneliness exacerbates psychological distress and increases the risk of psychopathology after trauma exposure. However, it is still unclear whether a lack of social connectedness affects trauma-related intrusions and the neural processing of fear signals. Moreover, it is uncertain, whether loneliness plays a different role in women and men. A prestratification strategy is used and n = 47 (n = 20 women) healthy lonely individuals and n = 35 controls (n = 18 women) are recruited. Participants are exposed to an experimental trauma and evoked intrusive thoughts in daily life are monitored for three consecutive days. Functional magnetic resonance imaging is used to assess neural habituation to fearful faces and fear learning (conditioning and extinction) prior to trauma exposure. The results reveal a significant interaction between loneliness and sex such that loneliness is associated with more intrusions in men, but not in women. A similar pattern emerges at the neural level, with both reduced amygdala habituation to repeated fearful faces and amygdala hyperreactivity during the conditioning of fear signals in lonely men. The findings indicate that loneliness may confer vulnerability to intrusive memories after trauma exposure in healthy men and that this phenotype relates to altered limbic processing of fear signals.

Considering Organismal Physiology in Laboratory Studies of Rodent Behavior

Any experiment conducted in a rodent laboratory is done so against the backdrop of each animal's physiological state at the time of the experiment. This physiological state can be the product of multiple factors, both internal (e.g., animal sex, strain, hormone cycles, or circadian rhythms) and external (e.g., housing conditions, social status, and light/dark phases). Each of these factors has the potential to influence experimental outcomes, either independently or via interactions with others, and yet there is little consistency across laboratories in terms of the weight with which they are considered in experimental design. Such discrepancies-both in practice and in reporting-likely contribute to the perception of a reproducibility crisis in the field of behavioral neuroscience. In this review, we discuss how several of these sources of variability can impact outcomes within the realm of common learning and memory paradigms. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Effects of circulating estradiol on physiological, behavioural, and subjective correlates of anxiety: A double-blind, randomized, placebo-controlled trial

Anxiety-related behaviours as well as the prevalence of anxiety disorders show a large sex difference in humans. Clinical studies in humans as well as behavioural studies in rodents suggest that estradiol may have anxiolytic properties. In line with this, anxiety symptoms fluctuate with estradiol levels along the menstrual cycle. However, the influence of estradiol on subjective, behavioural, as well as physiological correlates of anxiety has never been systematically addressed in humans. We ran a double-blind, randomized, placebo-controlled study (N = 126) to investigate the effects of estradiol on anxiety in men and women. In healthy volunteers, circulating estradiol levels were elevated through estradiol administration over two consecutive days to simulate the rise in estradiol levels around ovulation. Subjective, behavioral, as well as, physiological correlates of anxiety were assessed using a virtual reality elevated plus-maze (EPM). Estradiol treatment reduced the physiological stress response with blunted heart rate response and lower cortisol levels compared to placebo treatment in both sexes. In contrast, respiration frequency was only reduced in women after estradiol treatment. Behavioural measures of anxiety as well as subjective anxiety on the EPM were not affected by estradiol treatment. In general, women showed more avoidance and less approach behavior and reported higher subjective anxiety levels on the EPM than men. These results highlight the limited anxiolytic properties of circulating levels of estradiol in humans, which influence physiological markers of anxiety but not approach and avoidance behaviour or subjective anxiety levels.

Sex hormones and cortisol during experimental trauma memory consolidation: Prospective association with intrusive memories

Background Trauma- and stress-related disorders, such as post-traumatic stress disorder (PTSD), are more common in females than in males. Sex hormones affect learning and emotional memory formation and may be associated with the development of PTSD. Most previous studies have indexed these hormones in isolation. Objectives: To investigate associations of sex hormones and cortisol during memory consolidation on the development of intrusive memories. Methods: We employed an experimental trauma film paradigm in 61 healthy women and indexed salivary testosterone, progesterone, estradiol, and cortisol on day one and day two post experimental trauma exposure and their effects on intrusion frequency, distress, and vividness. Intrusive trauma memories were indexed by means of a diary in which participants documented intrusion frequency, distress, and vividness. Results and conclusion: Participants reported an average of 5.3 intrusions over the course of seven days (SD = 4.6, range 0-26). Progesterone, and estradiol indexed on day one predicted intrusion frequency, with higher progesterone and lower estradiol predicting more intrusive memories (p-values AUC progesterone 0.01 and estradiol 0.02). There was no evidence for associations between hormone concentration indices on day two and intrusion outcomes. Further research on the roles of gonadal and adrenal hormones in trauma memory formation is needed to advance our efforts to understand their influence on PTSD development.

Trauma Characteristics Moderate the Relation Between Estradiol and Trauma-Related Symptoms

Women are more likely to develop posttraumatic stress disorder (PTSD) than men, and fluctuations in gonadal hormones might contribute to this vulnerability. Low-estradiol states are associated with aversive affective experiences, including trauma-related symptoms. However, the impact of trauma characteristics on the relation between estradiol and trauma-related symptoms is unknown. We used a clinical interview and 10-day ecological momentary assessment (EMA) that spanned low- and high-estradiol menstrual cycle phases to test trauma type, chronicity, and timing as moderators of the association between estradiol and trauma-related symptoms in 40 naturally cycling young women. We tested interactions between trauma characteristics and (a) estradiol on self-reported symptoms and (b) menstrual cycle-related change in estradiol on change in symptoms. Sexual, chronic, and earlier trauma was associated with more severe symptoms as reported during the interview, rs = .51-.33, but not mean symptoms across the EMA. Estradiol at the time of the interview was inversely associated with symptoms in women with sexual but not nonsexual trauma, interaction: B = -12.62 (SE = 5.28), p = .022. Menstrual cycle-related change in estradiol was inversely associated with change in symptoms in women with chronic trauma, B = -9.65 (SE = 3.49), p = .006, and earlier trauma, B = 0.71 (SE = 0.34), p = .036, but not discrete or later trauma. Sexual, chronic, or early trauma exposure might confer higher symptom vulnerability in low-estradiol states. Clinicians who work with women with particular trauma histories might anticipate menstrual cycle-related variation in symptoms.

Estradiol effects on spatial memory in women

To examine the role of estradiol in hippocampal-dependent spatial memory in women, 86 female undergraduates were tested in a virtual Morris water task (VMWT), a virtual radial arm maze (VRAM), and a mental rotation task (MRT) within a single daily session. The VMWT and RAM were also administered 24 h later to examine the effects of estradiol on memory consolidation. Women on oral contraceptives (OCs) or those who were naturally cycling and exhibited low estradiol (LE) or high estradiol (HE), as determined by salivary assays, were included. At the start of day two, the HE group showed superior spatial reference memory on the VMWT relative to the LE group, as evidenced by significantly shorter distances navigating to the hidden platform. The LE group also had the poorest probe trial performance at the start of day two compared to both other groups. There were no group differences in performance on the RAM or MRT. These results provide support for estradiol's role in the consolidation of spatial reference memory in women, and emphasize the differential sensitivities of various virtual memory tasks in assessing spatial memory function in women.

Using Translational Models of Fear Conditioning to Uncover Sex-Linked Factors Related to PTSD Risk

Post-traumatic stress disorder (PTSD) is a debilitating neuropsychiatric disorder that follows exposure to a traumatic event; however, not every person who experiences trauma will develop PTSD. Women are more likely to be diagnosed with PTSD than men even when controlling for type and amount of trauma exposure. Circulating levels of gonadal hormones such as estradiol, progesterone, and testosterone may contribute to differential risk for developing PTSD. In this review, we briefly consider the influence of gonadal hormones on fear conditioning processes including fear acquisition, fear inhibition, extinction learning, and extinction recall within translational neuroscience models. We discuss findings from human studies incorporating samples from both community and traumatized clinical populations to further understand how these hormones might interact with exposure to trauma. Additionally, we propose that special attention should be paid to the specific measure used to examine fear conditioning processes as there is evidence that common psychophysiological indices such as skin conductance response and fear-potentiated startle can reveal quite different results and thus necessitate nuanced interpretations. Continued research to understand the influence of gonadal hormones in fear learning and extinction processes will provide further insight into the increased risk women have of developing PTSD and provide new targets for the treatment and prevention of this disorder.

Psychiatric Symptoms Across the Menstrual Cycle in Adult Women: A Comprehensive Review

LEARNING OBJECTIVE

After participating in this activity, learners should be better able to:• Discuss and outline the general and overlapping effects of the menstrual cycle on women's mental health.

ABSTRACT

A growing body of research demonstrates menstrual cycle-dependent fluctuations in psychiatric symptoms; these fluctuations can therefore be considered as prevalent phenomena. Possible mechanisms underlying these fluctuations posit behavioral, psychological, and neuroendocrine influences. Recent reviews document cyclic exacerbation of symptoms and explore these mechanisms in the context of specific and often single disorders. The question remains, however, as to whether there are general and overlapping effects of the menstrual cycle on women's mental health. To address this gap, we synthesized the literature examining the exacerbation of a variety of psychiatric symptoms across the menstrual cycle in adult women. Results show that the premenstrual and menstrual phases are most consistently implicated in transdiagnostic symptom exacerbation. Specifically, strong evidence indicates increases in psychosis, mania, depression, suicide/suicide attempts, and alcohol use during these phases. Anxiety, stress, and binge eating appear to be elevated more generally throughout the luteal phase. The subjective effects of smoking and cocaine use are reduced during the luteal phase, but fewer data are available for other substances. Less consistent patterns are demonstrated for panic disorder, symptoms of posttraumatic stress disorder, and borderline personality disorder, and it is difficult to draw conclusions for symptoms of generalized anxiety disorder, social anxiety disorder, obsessive-compulsive disorder, and trichotillomania because of the limited data. Future research should focus on developing standardized approaches to identifying menstrual cycle phases and adapting pharmacological and behavioral interventions for managing fluctuations in psychiatric symptoms across the menstrual cycle.

Prevalence and Associated Factors of PTSD Symptoms After the COVID-19 Epidemic Outbreak in an Online Survey in China: The Age and Gender Differences Matter

INTRODUCTION

The COVID-19 is a highly contagious disease belonging to the family of coronaviruses which can affect a great deal of people shortly. As a devastating event in the world, many people suffer the PTSD from this severe disease. The aim of study is to explore the prevalence and severity of post-traumatic stress disorder (PTSD) symptoms, and discuss the possible factors among the general public in China after the COVID-19 epidemic outbreak.

METHODS

This is a cross-sectional study. We used the self-designed demographic questionnaire and the Posttraumatic Stress Checklist-Civilian Version (PCL-C) of Chinese version as our screening tools to investigate 4872 subjects living in the communities in China from Nov. 8th, 2020 to Dec. 8th, 2020.

RESULTS

Finally, we received 3705 effective respondents. The response rates of the questionnaire can reach 76.97 percentage. Peculiarly, the prevalence of PTSD mild and severe symptoms after the COVID-19 epidemic outbreak was 53.2%. Mild PTSD symptoms accounted for 24.9%, and severe PTSD symptoms (scores above 38) accounted for 28.3%. PCL-C mean scores were 41.4±14.7. The females accounted for 67.7% of the total samples. Participants' mean age was 30.5±11.2 years old. The PCL-C gross scores of females were all higher than males in four subject groups. Meantime, gender and age made differences not only in total PCL-C points but also in the four aspects of PCL-C (P<0.001). The middle-aged group (ages from 45 to 60) got the lowest scores among the four groups.

CONCLUSION

COVID-19 brought tremendous psychological pressure on the public in many ways, including people's work, social contact, study, and daily life. Results of our research discover that symptoms of the PTSD are severe, including the re-experiencing, avoidance/numbing, flashbacks, and hyper-arousal. Actions should be taken at society level to prevent and protect individuals from PTSD suffering. Special attention should be paid to females and young people. Further studies should be conducted to explore the dynamic and other risk and protection factors to prevent PTSD.

Translation of animal endocannabinoid models of PTSD mechanisms to humans: Where to next?

The endocannabinoid system is known to be involved in mechanisms relevant to PTSD aetiology and maintenance, though this understanding is mostly based on animal models of the disorder. Here we review how human paradigms can successfully translate animal findings to human subjects, with the view that substantially increased insight into the effect of endocannabinoid signalling on stress responding, emotional and intrusive memories, and fear extinction can be gained using modern paradigms and methods for assessing the state of the endocannabinoid system in PTSD.

Gonadal steroid hormones and emotional memory consolidation: A systematic review and meta-analysis

Anxiety and stress-related disorders are more prevalent in women and associated with negative emotional memory consolidation as well as impaired fear extinction recall. Recent research has identified a role of gonadal steroid hormones in influencing emotional memories and fear extinction, however most individual studies have small samples and employed various protocols. A systematic review and meta-analysis were conducted on studies that examined sex hormones (estrogen, progesterone, testosterone, allopregnanolone, dehydroepiandrosterone) on four aspects of memory, namely, intentional recall (k = 13), recognition memory (k = 7), intrusive memories (k = 9), and extinction recall (k = 11). The meta-analysis on natural cycling women revealed that progesterone level was positively associated with negative recall and negative intrusive memories, and this effect on intentional recall was enhanced under stress induction. Estradiol level was positively associated with extinction recall. This study reveals an important role of progesterone and estradiol in influencing emotional memory consolidation. It highlights the need to control for these hormonal effects and examine progesterone and estradiol concurrently across all menstrual phases in future emotional memory paradigms.

Beyond Efficacy and Effectiveness: Clinical Efficiency Is Necessary for Dissemination

Nearly all patients interact with critical gatekeepers-insurance companies or centralized healthcare systems. For mental health dissemination efforts to be successful, these gatekeepers must refer patients to evidence-based care. To make these referral decisions, they require evidence about the amount of resources expended to achieve therapeutic gains. Without this information, a bottleneck to widespread dissemination of evidence-based care will remain. To address this need for information, we introduce a new perspective, clinical efficiency. This approach directly ties resource usage to clinical outcomes. We highlight how cost-effectiveness approaches and other strategies can address clinical efficiency, and we also introduce a related new metric, the incremental time efficiency ratio (ITER). The ITER is particularly useful for quantifying the benefits of low-intensity and concentrated interventions, as well as stepped-care approaches. Given that stakeholders are increasingly requiring information on resource utilization, the ITER is a metric that can be estimated for past and future clinical trials. As a result, the ITER can allow researchers to better communicate desirable aspects of treatment, and an increased focus on clinical efficiency can improve our ability to deliver high-quality treatment to more patients in need.

Intrusive memories as conditioned responses to trauma cues: An empirically supported concept?

Intrusions in posttraumatic stress disorder (PTSD) are clinically understood as conditioned responses (CRs) to trauma-cues; however, experimental evidence for this is limited. We subjected 84 healthy participants to a differential conditioned-intrusion paradigm, where neutral faces served as conditioned stimuli (CSs) and aversive film clips as unconditioned stimuli (USs). While one group only completed acquisition, another group additionally received extinction. Subsequently, participants provided detailed e-diary intrusion reports. Several key findings emerged: First, participants in both groups re-experienced not only USs but also CSs as content of their intrusions. Second, intrusions were elicited by cues resembling CSs, USs, and experimental context. Third, extinction reduced probability and severity of US intrusions, and accelerated their decay, and this was particularly the case in participants showing greater cognitive (US-expectancy) and physiological (SCR) differential responding to CS+ vs. CS- at end of acquisition (i.e., conditionability). Similarly, extinction reduced CS-intrusion probability and severity, but only in participants with greater cognitive conditionability. These results support conditioning's role in re-experiencing in two critical ways: (1) Conditioning during trauma provides cues that not only function as reminder cues, but also as content of intrusions; (2) After strong conditioning, weakening the original CS-US relationship via extinction reduces intrusion formation after analogue-trauma.

The Effect of Self-Reported REM Behavior Disorder Symptomology on Intrusive Memories in Post-Traumatic Stress Disorder

Background: PTSD is characterised by severe sleep disturbances, which is increasingly recognised to in many cases consist of similar symptomology to sleep disorders such as REM Behaviour Disorder (RBD). The present study aimed to investigate whether different aspects of sleep quality influence intrusive memory development and whether PTSD status moderates this relationship. Participants and Methods: 34 PTSD, 52 trauma-exposed (TE) and 42 non-trauma exposed (NTE) participants completed an emotional memory task, where they viewed 60 images (20 positive, 20 negative and 20 neutral) and, two days later, reported how many intrusive memories they had of each valence category. Participants also completed three measures of sleep quality: the Pittsburgh Sleep Quality Index, the REM Behaviour Disorder Screening Questionnaire and total hours slept before each session. Results: The PTSD group reported poorer sleep quality than both TE and NTE groups on all three measures, and significantly more negative intrusive memories than the NTE group. Mediation analyses revealed that self-reported RBD symptomology before the second session mediated the relationship between PTSD status and intrusive memories. Follow-up moderation analyses revealed that self-reported RBD symptomology before the second session was only a significant predictor of intrusion in the PTSD group, though with a small effect size. Conclusions: These findings suggest that RBD symptomology is an indicator of consolidation of intrusive memories in PTSD but not trauma-exposed or healthy participants, which supports the relevance of characterising RBD in PTSD.

The renin-angiotensin system in PTSD: a replication and extension

Prior observational studies have suggested that medications targeting the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs), may be associated with decreased PTSD symptoms. Given known sex differences in PTSD prevalence and cardiovascular disease, here we tested whether the effects of ACE-I/ARB status on PTSD differ by sex. We also expanded these observations with replication analyses in a large biorepository database. Participants in the initial sample included 840 trauma-exposed individuals recruited as part of the Grady Trauma Project. The Modified PTSD Symptom Scale (M-PSS) was administered and ACE-I/ARB status was determined by self-report. Replication analyses were conducted using a large biorepository database (Partners Healthcare Biobank, N = 116,389) with diagnoses and medication status based on available electronic health records. Among individuals treated with ACE-Is/ARBs in the initial sample, women had significantly higher M-PSS total and Re-experiencing severity compared to men (p's < 0.05). Analyses with the large biorepository sample robustly replicated the overall effects of ACE-I/ARB medication associated with lower rate of PTSD diagnosis (p < 0.001). We also demonstrated that this effect may be specific to the renin-angiotensin system as it did not replicate for beta-blockers, calcium channel blockers, or diuretics. When we examined more specific drug classes, results indicated that the ACE-I/ARB effect on PTSD may be driven more by ARBs (e.g., Losartan) than by ACE-Is. Post-hoc analyses indicated that racial differences may exist in these effects. Overall, our results replicate and extend prior observations that the renin-angiotensin system is associated with PTSD. Medications targeting this system may be worthy of further investigation for PTSD treatment. Our findings suggest that sex and race effects should be considered in future treatment research.

Estradiol and Women's Health: Considering the Role of Estradiol as a Marker in Behavioral Medicine

The sex hormone estradiol, as measured through saliva, represents a non-invasive and cost-effective approach to understanding the influence of hormonal factors on physical and psychological well-being among women. Estradiol levels dramatically change at hormonal transitions, such as puberty, menopause, and postpartum. It is at these transitions where women are at increased risk for psychological and somatic distress. Salivary estradiol also has implications for decision-making and has been broadly associated with engagement in health-compromising behaviors which can influence women's ability to cope with and manage chronic health conditions. This review summarizes the evidence for salivary estradiol as a marker of physical and psychological health, and discusses practical information regarding saliva collection and assay. The overall intent is to expand and clarify knowledge of the relation between changes in salivary estradiol and women's health as well as to provide a means of integrating salivary estradiol into future behavioral medicine research.

Sleep Changes Across the Female Hormonal Cycle Affecting Memory: Implications for Resilient Adaptation to Traumatic Experiences

We review findings and propose a model explaining why women's adaptation to traumatic stress might be different than men's, including the role of cycling hormones and sleep differences in the development of post-traumatic stress and other stress-related disorders. Women are diagnosed with stress-related mental health disorders at a higher frequency than men. Most mental health disorders involve sleep disturbances, which may contribute to these disorders. The mechanisms by which sleep contributes to the development of mental health disorders in women have not been addressed in basic research. Sleep features such as spindle density and rapid eye movement (REM) sleep theta power are important for the role of sleep in emotion and cognition. The effect of hormonal cycles on these and other critical sleep features is only beginning to be understood. We explore what sleep factors could confer resilience to mental health disorders and how they might be altered by hormonal cycles in women. We target a specific system at the nexus of arousal control, stress response, and memory consolidation processes that has not been explored at all in women or across the hormonal cycle in animal studies: the locus coeruleus noradrenergic (LC-NE) system.

Methodische Anmerkungen und Anwendungsbereiche der Furchtkonditionierung in verschiedenen psychologischen Disziplinen

Zusammenfassung. Die Furchtkonditionierung stellt ein bedeutsames Paradigma zur Untersuchung von emotionalen Lern- und Gedächtnisprozessen dar. Nach einer ungefähr hundertjährigen Geschichte wird deutlich, dass die Furchtkonditionierung nicht nur einen wichtigen Beitrag zur speziesübergreifenden Grundlagenforschung liefert, sondern auch unterschiedliche Anwendungsfelder zu neuen Erkenntnissen inspirieren kann. In diesem Übersichtartikel soll das grundlegende Paradigma mit verschiedenen methodischen Überlegungen zur experimentellen Durchführung vorgestellt werden. Im Anschluss werden ausgewählte Anwendungsbereiche der Furchtkonditionierung innerhalb der psychologischen Disziplinen dargestellt: die Allgemeine Psychologie wird bezüglich allgemeingültiger Gesetzmäßigkeiten von Lern- und Gedächtnisprozessen angesprochen, die Differentielle Psychologie wegen bedeutsamer interindividueller Unterschiede, die Biologische Psychologie und Neuropsychologie in Bezug auf physiologische und anatomische Grundlagen der Furchtkonditionierung, die Sozialpsychologie im Zuge der Einstellungsforschung, die Entwicklungspsychologie aufgrund altersspezifischer Aspekte sowie die Klinische Psychologie und Psychotherapie im Hinblick auf die Pathogenese von Angsterkrankungen und der Expositionstherapie. Insgesamt betrachtet hat die Furchtkonditionierung das Potenzial nicht nur unterschiedliche Disziplinen der Psychologie in synergistischer Weise zusammenzubringen, sondern auch die verschiedenen inhaltlichen Schwerpunkte zu unterstreichen.

The neurobiological basis of sex differences in learned fear and its inhibition

Learning that certain cues or environments predict threat enhances survival by promoting appropriate fear and the resulting defensive responses. Adapting to changing stimulus contingencies by learning that such cues no longer predict threat, or distinguishing between these threat-related and other innocuous stimuli, also enhances survival by limiting fear responding in an appropriate manner to conserve resources. Importantly, a failure to inhibit fear in response to harmless stimuli is a feature of certain anxiety and trauma-related disorders, which are also associated with dysfunction of the neural circuitry underlying learned fear and its inhibition. Interestingly, these disorders are up to twice as common in women, compared to men. Despite this striking sex difference in disease prevalence, the neurobiological factors involved remain poorly understood. This is due in part to the majority of relevant preclinical studies having neglected to include female subjects alongside males, which has greatly hindered progress in this field. However, more recent studies have begun to redress this imbalance and emerging evidence indicates that there are significant sex differences in the inhibition of learned fear and associated neural circuit function. This paper provides a narrative review on sex differences in learned fear and its inhibition through extinction and discrimination, along with the key gonadal hormone and brain mechanisms involved. Understanding the endocrine and neural basis of sex differences in learned fear inhibition may lead to novel insights on the neurobiological mechanisms underlying the enhanced vulnerability to develop anxiety-related disorders that are observed in women.

Assessment of conditioned fear extinction in male and female adolescent rats

Pavlovian fear conditioning and extinction have been widely studied across many species to understand emotional learning and memory. Importantly, it is becoming clear that these processes are affected by sex and age. In adult rodents and humans, sex differences are evident in extinction, with estradiol playing a significant role. In adolescence, an extinction deficit has been reported in rodents and humans. However, the influence of sex on extinction during adolescence is unknown. This is surprising, since adolescence coincides with the onset of hormone cycling, and therefore it might be expected that hormones fluctuations exert a more profound effect at this time. Therefore, we examined Pavlovian fear conditioning and extinction in adolescent male and female rats. In experiment 1, 35-day-old male and female rats were exposed to 6 pairings of a conditioned stimulus (CS, a tone) with an aversive unconditioned stimulus (US, a footshock). The next day they were extinguished in a contextually distinct chamber, via 60 presentations of the CS without the US. Extinction recall was tested 24 hours later in the extinction context. Estrous phase was monitored by cytology on vaginal smears taken 1 hour after each behavioral session. In experiment 2, male and female rats were given sham surgery or gonadectomy at 21 days of age. They were then trained and tested as for experiment 1. We observed that females in proestrus or met/diestrus during extinction showed delayed extinction and impaired extinction recall the next day compared to males. Ovariectomy enhanced extinction for female rats, but orchidectomy delayed extinction for males. Plasma analyses showed that met/di/proestrus phases were associated with high estradiol levels. These findings suggest that high plasma estradiol levels impair extinction for adolescent females. These results contradict what is reported in adult animals, suggesting that hormonal influences on extinction are dependent on age. Given that impaired extinction is widely used as a model to understand resistance to exposure-based therapies, our findings have important implications for understanding mental health treatments in adolescents.

Hormonal, reproductive, and behavioural predictors of fear extinction recall in female rats

The prevalence, severity and chronicity of anxiety disorders is significantly higher in women compared to men. Exposure therapy, the gold-standard treatment for anxiety disorders, can be modelled in the laboratory through Pavlovian fear extinction. Understanding the factors that influence fear extinction in females may aid in optimising the treatment of anxiety disorders in this population. The aim of the current study was therefore to explore the hormonal, reproductive and behavioural predictors of fear extinction recall in female rats by analysing data from nine published experiments that examined fear extinction in female rats. A hierarchical multiple regression analysis revealed that estrous cycle effects on extinction recall may be modulated by reproductive status. While the estrous phase in which nulliparous (virgin) rats undergo extinction training was predictive of extinction recall, no relationship between estrous phase and extinction recall was found among primiparous (one prior reproductive experience) rats. Moreover, estrous cycle predicted the relationship between early extinction and extinction recall in nulliparous rats, but not primiparous rats. Although reproductive status did not predict extinction recall, primiparous rats exhibited poor extinction recall relative to nulliparous rats extinguished during proestrus, and better extinction recall than nulliparous rats extinguished during metestrus. A faster rate of extinction, and lower fear responses at the end of extinction training were predictive of lower levels of CS-elicited fear during extinction recall in both nulliparous and primiparous female rats, while the length of extinction training was not predictive of extinction recall. The potential theoretical and clinical implications of these findings are discussed.

Investigating hormone-induced changes in affective state using the affective bias test in male and female rats

Recent clinical and pre-clinical research suggests that affective biases may play an important role in the development and perpetuation of mood disorders. Studies in animals have also revealed that similar neuropsychological processes can be measured in non-human species using behavioural assays designed to measure biases in learning and memory or decision-making. Given the proposed links between hormones and mood, we used the affective bias test to investigate the effects of different hormone treatments in both male and female rats. Animals were pre-treated with acute doses of hormone or vehicle control prior to learning each of two independent substrate-reward associations. During a subsequent choice test, positive or negative biases were observed by animal's preference towards or away from the substrate learnt during drug treatment respectively. In both sexes, oestradiol and the oestrogen-like compound bisphenol A induced positive biases, whilst blockade of oestrogen hormones with formestane induced a negative bias. Progesterone induced a negative bias in both sexes, but testosterone only induced a negative bias in males. Blocking testosterone with flutamide induced a positive bias in both sexes at the higher dose (10 mg/kg). The oxytocin analogue, carbetocin induced positive biases in both sexes but the vasopressin analogue, desmopressin, induced a positive bias in male rats only. These results provide evidence that modulating levels of hormones using exogenous treatments can induce affective biases in rats. They also suggest that hormone-induced affective biases influence cognitive and emotional behaviour and could have longer-term effects in some mood disorders.

Estradiol Modulates Neural and Behavioral Arousal in Women With Posttraumatic Stress Disorder During a Fear Learning and Extinction Task

BACKGROUND

Fear responding in posttraumatic stress disorder (PTSD) is sexually heterogeneous and varies with hormonal fluctuations throughout the menstrual cycle. While research suggests that estrogen levels affect PTSD symptoms among women, there is a dearth of research on modulatory effects of estrogen on fear responding among women with PTSD, and neural outcome measures are lacking.

METHODS

A sample of 42 women with PTSD underwent 2 consecutive alternating blocks of fear conditioning and extinction training, during which a CS+ conditioned stimulus, but not a CS-, predicted the occurrence of an electric shock in an acquisition context but not in an extinction context. Assayed saliva determined estradiol levels. Skin conductance response and whole-brain voxelwise activity during functional magnetic resonance imaging were outcome variables in linear mixed-effects models, with estradiol level, PTSD severity, and task contrasts as predictors.

RESULTS

Skin conductance response exhibited a significant estradiol × PTSD severity × habituation interaction (t = 3.180, p = .002), such that PTSD severity was correlated with increased arousal responding between training blocks among women with lower estradiol (t = -3.985, p < .001) but not higher estradiol (t = 0.550, p = .583). Voxelwise activity also demonstrated an identical three-way interaction within dorsomedial prefrontal cortex and anterior insula clusters. The skin conductance response and imaging interactions between PTSD severity and estradiol were not specific to conditioned stimulus type or context.

CONCLUSIONS

Estradiol moderated the relationship between PTSD severity and arousal response habituation between fear conditioning and extinction training sessions, such that high estradiol protected against the negative impact of severe PTSD symptoms on fear habituation. These findings suggest that estrogen enhances habituation among women with severe PTSD, potentially influencing the efficacy of extinction-based therapies.

The role of catecholamines in modulating responses to stress: Sex-specific patterns, implications, and therapeutic potential for post-traumatic stress disorder and opiate withdrawal

Emotional arousal is one of several factors that determine the strength of a memory and how efficiently it may be retrieved. The systems at play are multifaceted; on one hand, the dopaminergic mesocorticolimbic system evaluates the rewarding or reinforcing potential of a stimulus, while on the other, the noradrenergic stress response system evaluates the risk of threat, commanding attention, and engaging emotional and physical behavioral responses. Sex-specific patterns in the anatomy and function of the arousal system suggest that sexually divergent therapeutic approaches may be advantageous for neurological disorders involving arousal, learning, and memory. From the lens of the triple network model of psychopathology, we argue that post-traumatic stress disorder and opiate substance use disorder arise from maladaptive learning responses that are perpetuated by hyperarousal of the salience network. We present evidence that catecholamine-modulated learning and stress-responsive circuitry exerts substantial influence over the salience network and its dysfunction in stress-related psychiatric disorders, and between the sexes. We discuss the therapeutic potential of targeting the endogenous cannabinoid system; a ubiquitous neuromodulator that influences learning, memory, and responsivity to stress by influencing catecholamine, excitatory, and inhibitory synaptic transmission. Relevant preclinical data in male and female rodents are integrated with clinical data in men and women in an effort to understand how ideal treatment modalities between the sexes may be different.

Neural Processing During Fear Extinction Predicts Intrusive Memories

BACKGROUND

Deficient extinction learning has been suggested as an important mechanism involved in the etiology of posttraumatic stress disorder. A key feature of posttraumatic stress disorder, reexperiencing the trauma in form of intrusions, may be linked to deficient extinction learning. This link is investigated in a novel, functional magnetic resonance imaging-compatible fear conditioning procedure that uses trauma films. Based on previous results, we expected deficient fear extinction indexed by exaggerated responding in the anterior insula and dorsal anterior cingulate cortex to predict subsequent intrusions.

METHODS

A total of 58 healthy participants underwent acquisition and extinction learning with faces as conditioned stimuli (CS) and highly aversive 16-second films depicting interpersonal violence as unconditioned stimuli. During the subsequent 3 days, participants reported intrusive memories on their smartphone.

RESULTS

Successful fear acquisition was evidenced by differential (CS+ > CS-) activity (threat cues associated with trauma films > cues paired only with neutral films) of a widespread network, including the anterior insula and dorsal anterior cingulate cortex, whereas extinction was characterized exclusively by differential anterior insula activity. Differential conditioned responding during late extinction in the anterior insula and dorsal anterior cingulate cortex was positively related to intrusive memory frequency independent of unconditioned stimuli responding. Exploratory analysis also revealed intrusion sensitivity of the hippocampus, rostral anterior cingulate cortex, and ventromedial prefrontal cortex, among others.

CONCLUSIONS

Results support the role of extinction learning in intrusive memory formation; a failure to uncouple conditioned emotional responding from external threat cues was associated with subsequent intrusive memories, representing a potential risk marker for developing posttraumatic stress disorder symptomatology after trauma.

The BDNF Val66Met polymorphism affects negative memory bias in civilian women with PTSD

Memory abnormalities are considered a core feature of posttraumatic stress disorder (PTSD). Studies attempting to quantify such memory dysfunction in PTSD have reported that individuals with this disorder exhibit selective memory bias toward negative material. The low expression Met allele of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism has been associated with the aetiology of PTSD and with memory abnormalities. It is therefore possible that the BDNF Val66Met polymorphism can moderate the relationship between PTSD and memory bias. Here we examined this association in 50 civilian women with PTSD and 70 non-trauma-exposed healthy control women. All subjects were genotyped for the BDNF Val66Met (rs6265) polymorphism. Negative memory bias was assessed using a recognition memory task. Patients showed significantly greater negative memory bias compared to controls. In patients, negative memory bias significantly increased with increasing numbers of Met alleles; while no significant relationship was seen in controls. Further pairwise analyses revealed that patients with the Met allele had significantly greater negative memory bias than controls. These results suggest that the relationship between PTSD and negative memory bias can be moderated by the BDNF Val66Met polymorphism. More studies are needed to further clarify the relationship between this polymorphism and memory abnormalities in PTSD.

The Role of Hormonal and Reproductive Status in the Treatment of Anxiety Disorders in Women

Exposure therapy, a key treatment for anxiety disorders, can be modelled in the laboratory using Pavlovian fear extinction. Understanding the hormonal and neurobiological mechanisms underlying fear extinction in females, who are twice more likely than males to present with anxiety disorders, may aid in optimising exposure therapy outcomes in this population. This chapter will begin by discussing the role of the sex hormones, estradiol and progesterone, in fear extinction in females. We will also propose potential mechanisms by which these hormones may modulate fear extinction. The second half of this chapter will discuss the long-term hormonal, neurological and behavioural changes that arise from pregnancy and motherhood and how these changes may alter the features of fear extinction in females. Finally, we will discuss implications of this research for the treatment of anxiety disorders in women with and without prior reproductive experience.

Translational studies of estradiol and progesterone in fear and PTSD

Translational models of fear have greatly informed our understanding of PTSD and its underlying fear circuitry. One of the most replicated findings in the field is the two-fold higher PTSD incidence in females compared to males. While sociocultural factors play a role, the most robust biological influencers to date are gonadal hormones, such as estradiol and progesterone, which fluctuate across the menstrual cycle. Among studies that account for these hormones, most do so in isolation or collect both and only report one. Variation in study findings suggests that the ratio between these two hormones (the P/E ratio) may be an important and missing variable to further understand gonadal hormone influences on fear. Here we review cross-species examinations of fear and PTSD, within the contexts of estradiol and progesterone as well as P/E ratios that were calculated based on extant literature. We then provide recommendations for best practices in assay methods and reporting to improve research on the P/E ratio in fear and PTSD. Ultimately, greater understanding of this important variable will advance efforts to characterize gonadal hormone influences on fear learning processes in humans and animals.

Acute ovarian hormone treatment in freely cycling female rats regulates distinct aspects of heroin seeking

Females are at higher risk for certain opioid addictive behaviors, but the influence of ovarian hormones is unknown. In our rat model of heroin self-administration, females exhibited higher relapse rates that correlated with rates of heroin seeking on the first extinction session. We administered estradiol alone, or in combination with progesterone, 30 min prior to the first extinction session in freely cycling, heroin-seeking female rats. Although neither treatment produced long-term effects on relapse, each treatment regulated distinct aspects of heroin seeking. Estradiol treatment enhanced extinction memory retention, whereas the combination treatment acutely reduced expression of heroin seeking.

An alternative theory for hormone effects on sex differences in PTSD: The role of heightened sex hormones during trauma

Women are at least twice as susceptible to developing post-traumatic stress disorder (PTSD) compared to men. Although most research seeking to explain this discrepancy has focussed on the role of oestradiol during fear extinction learning, the role of progesterone has been overlooked, despite relatively consistent findings being reported concerning the role of progesterone during consolidation of emotional and intrusive memories. In this review article, we outline literature supporting the role of progesterone on memory formation, with particular emphasis on potential memory-enhancing properties of progesterone when subjects are placed under stress. It is possible that progesterone directly and indirectly exerts memory-enhancing effects at the time of trauma, which is an effect that may not be necessarily captured during non-stressful paradigms. We propose a model whereby progesterone's steroidogenic relationship to cortisol and brain-derived neurotrophic factor in combination with elevated oestradiol may enhance emotional memory consolidation during trauma and therefore present a specific vulnerability to PTSD formation in women, particularly during the mid-luteal phase of the menstrual cycle.