[Show abstract][Hide abstract] ABSTRACT: The prefrontal cortex (PFC) provides executive control of the brain in humans and rodents, coordinating cognitive, emotional, and behavioral responses to threatening stimuli and subsequent feedback inhibition of the hypothalamic-pituitary-adrenal (HPA) axis. The endocannabinoid system has emerged as a fundamental regulator of HPA axis feedback inhibition and an important modulator of emotional behavior. However, the precise role of endocannabinoid signaling within the PFC with respect to stress coping and emotionality has only recently been investigated. This review discusses the current state of knowledge regarding the localization and function of the endocannabinoid system in the PFC, its sensitivity to stress and its role in modulating the neuroendocrine and behavioral responses to aversive stimuli. We propose a model whereby steady-state endocannabinoid signaling in the medial PFC indirectly regulates the outflow of pyramidal neurons by fine-tuning GABAergic inhibition. Local activation of this population of CB1 receptors increases the downstream targets of medial PFC activation, which include inhibitory interneurons in the basolateral amygdala, inhibitory relay neurons in the bed nucleus of the stria terminalis and monoamine cell bodies such as the dorsal raphe nucleus. This ultimately produces beneficial effects on emotionality (active coping responses to stress and reduced anxiety) and assists in constraining activation of the HPA axis. Under conditions of chronic stress, or in individuals suffering from mood disorders, this system may be uniquely recruited to help maintain appropriate function in the face of adversity, while breakdown of the endocannabinoid system in the medial PFC may be, in and of itself, sufficient to produce neuropsychiatric illness. Thus, we suggest that endocannabinoid signaling in the medial PFC may represent an attractive target for the treatment of stress-related disorders.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to investigate the sexual beliefs of female undergraduates, as well as the thoughts they experience during sexual experiences. The study aimed to determine potential differences in these variables between East Asian-Canadians and Euro-Canadians, as well as the influence of acculturation on these variables. In addition, the relationships between sexual beliefs, automatic thoughts, and specific aspects of sexual functioning were examined. Euro-Canadian (n = 77) and East Asian-Canadian (n = 123) undergraduate women completed the Sexual Dysfunctional Beliefs Questionnaire, the Sexual Modes Questionnaire, the Female Sexual Function Index, and the Vancouver Index of Acculturation. East Asian women endorsed almost all sexual beliefs assessed in this study more than did Euro-Canadian women, and endorsement of these beliefs was associated with acculturation. In addition, East Asian-Canadian and Euro-Canadian women differed in the frequency of experiencing negative automatic thoughts. Results also revealed associations between difficulties in sexual functioning, and both sexual beliefs and automatic thoughts. Together, these results provide preliminary support for the hypothesis that differences in cognitive aspects of sexuality may underlie the differences in sexual functioning previously observed between these two groups.
Archives of Sexual Behavior 09/2013; · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human asexuality is defined as a lack of sexual attraction to anyone or anything and it has been suggested that it may be best conceptualized as a sexual orientation. Non-right-handedness, fraternal birth order, and finger length ratio (2D:4D) are early neurodevelopmental markers associated with sexual orientation. We conducted an Internet study investigating the relationship between self-identification as asexual, handedness, number of older siblings, and self-measured finger-lengths in comparison to individuals of other sexual orientation groups. A total of 325 asexuals (60 men and 265 women; M age, 24.8 years), 690 heterosexuals (190 men and 500 women; M age, 23.5 years), and 268 non-heterosexuals (homosexual and bisexual; 64 men and 204 women; M age, 29.0 years) completed online questionnaires. Asexual men and women were 2.4 and 2.5 times, respectively, more likely to be non-right-handed than their heterosexual counterparts and there were significant differences between sexual orientation groups in number of older brothers and older sisters, and this depended on handedness. Asexual and non-heterosexual men were more likely to be later-born than heterosexual men, and asexual women were more likely to be earlier-born than non-heterosexual women. We found no significant differences between sexual orientation groups on measurements of 2D:4D ratio. This is one of the first studies to test and provide preliminary empirical support for an underlying neurodevelopmental basis to account for the lack of sexual attraction characteristic of asexuality.
Archives of Sexual Behavior 09/2013; · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: Despite extensive efforts to raise awareness, Papanicolaou (Pap) testing rates among Chinese women living in North America remain low compared with Euro-American women. Although the lower Pap testing rate and ensuing health repercussions among Chinese women are well characterized, mechanisms underlying such health disparities are not. The aim of this study was to use a qualitative approach to delineate such mechanisms. Qualitative approaches to understand constructs within the domain of sexual and reproductive health have been shown to be particularly appropriate, and offer a nuanced view of sexuality that is not afforded by traditional quantitative methods.Method: We carried out two focus groups aimed at exploring how Mandarin-speaking and English-speaking Chinese women experience Pap testing (N = 12). The women were invited to partake in the focus groups from having participated in a large-scale quantitative study. Participants were all first-generation immigrants and their average age was 53-years-old. We used content analyses to analyze transcripts and extract themes.Results and Discussion: The women heavily endorsed traditional Chinese medicine philosophy, conceptualizing physical health holistically, and valuing preventative measures over screening and interceptive measures. Pap testing was described as qualitatively different from other screening procedures, such that women assigned a sexually charged meaning to Pap testing, often discussing it in relation to sexual activity and promiscuity. Women expressed their preference for the compulsory and depersonalized manner that Pap tests are performed in their home country of China, as this lessens the embarrassment associated with undergoing Pap testing.Conclusion: Three mechanisms may contribute to lower Pap testing among middle-aged first-generation Chinese immigrants: preference for Chinese medicine philosophy, perceived sexualization of Pap testing, and the institutionalization of medical care. Implications for improving the reproductive health of Chinese women are discussed.
[Show abstract][Hide abstract] ABSTRACT: Accumulating evidence has revealed that dysregulation of the endocannabinoid system could contribute to the development of major depression. Studies carried out post-mortem in depressed suicide victims have revealed increased CB(1) receptor binding site density in the prefrontal cortex (PFC). Accordingly, exposure of rodents to chronic unpredictable stress (CUS) results in phenotypic changes that mirror those of human depression, including increased CB(1) receptor binding site density in the PFC. Our goal in these studies was to examine the effects of CUS on the density of CB(1) receptor binding sites in the rodent medial PFC and to explore the role of this alteration in the behavioral changes invoked by CUS. Rodents exposed to CUS exhibited increased CB(1) receptor maximal binding site density (B(max)) within the ventromedial PFC, but not the dorsomedial PFC. To determine whether this change in the ventromedial PFC is an adaptive response, or alternatively, a consequence of chronic stress that contributes to the adoption of passive coping, we examined whether local CB(1) receptor blockade within the ventromedial PFC following CUS would significantly alter behaviors in the forced swim test (FST). CUS exposure significantly increased passive coping in the FST, and this was further augmented by discrete ventromedial PFC microinfusions of the CB(1) receptor antagonist AM251 prior to swim stress. Moreover, local CB(1) receptor blockade reduced active coping responses in CUS-exposed rats. These findings suggest that the increase in CB(1) receptor B(max) observed in the ventromedial PFC of rodents exposed to CUS maintains proactive coping strategies following chronic stress exposure.
Behavioural brain research 10/2012; 237C:333-337. · 3.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fifty-nine heterosexual university males were assessed for Sexual Coercion Proclivity (SCP) and randomly assigned to one of three conditions: Insult/nonsexually coercive fantasy material; no insult/sexually coercive fantasy material; or, insult/sexually coercive fantasy material. Although not differing in terms of anger or anxiety, the high SCP became more frustrated than the low group, particularly when exposed to both insult and sexually coercive (SC) fantasy material. Changes in negative affect predicted anticipated likelihood of engaging in SC among the low SCP group and anticipated enjoyment of SC in the high SCP group. Acculturation accounted for differences observed between Caucasian and Chinese men.
Violence Against Women 08/2012; 18(8):973-95. · 1.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The chronic mild (or unpredictable/variable) stress (CMS) model was developed as an animal model of depression more than 20 years ago. The foundation of this model was that following long-term exposure to a series of mild, but unpredictable stressors, animals would develop a state of impaired reward salience that was akin to the anhedonia observed in major depressive disorder. In the time since its inception, this model has also been used for a variety of studies examining neurobiological variables that are associated with depression, despite the fact that this model has never been critically examined to validate that the neurobiological changes induced by CMS are parallel to those documented in depressive disorder. The aim of the current review is to summarize the current state of knowledge regarding the effects of chronic mild stress on neurobiological variables, such as neurochemistry, neurochemical receptor expression and functionality, neurotrophin expression and cellular plasticity. These findings are then compared to those of clinical research examining common variables in populations with depressive disorders to determine if the changes observed following chronic mild stress are in fact consistent with those observed in major depression. We conclude that the chronic mild stress paradigm: (1) evokes an array of neurobiological changes that mirror those seen in depressive disorders and (2) may be a suitable tool to investigate novel systems that could be disturbed in depression, and thus aid in the development of novel targets for the treatment of depression.
[Show abstract][Hide abstract] ABSTRACT: Evidence for the influence of sexual beliefs on sexual functioning and satisfaction has mainly emanated from clinical lore. Empirical investigations on this topic remain sparse. This study investigated whether beliefs regarding prevalence and definitions of male and female sexual dysfunctions predicted sexual function and satisfaction in a sample of 131 undergraduate students. Results indicated that higher perceived prevalence of male and female sexual dysfunctions was predictive of lower sexual functioning and poorer sexual satisfaction in women. For the male participants, none of the examined sexual beliefs emerged as significant predictors of their sexual functioning or satisfaction. Surprisingly, it was also found that participants estimated the prevalence of female sexual dysfunctions to be higher than male sexual dysfunctions, while defining male sexual dysfunctions more broadly than female sexual dysfunctions. Possible mechanisms for the findings are provided.
The Journal of Sex Research 04/2012; · 2.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Several lines of evidence point to the potential role of the endocannabinoid system in female sexual functioning. These include results from studies describing the subjective effects of exogenous cannabinoids on sexual functioning in humans and the observable effects of exogenous cannabinoids on sexual functioning in other species, as well as results from studies investigating the location of cannabinoid receptors in the brain and periphery, and the effects of cannabinoid receptor activation on neurotransmitters implicated in sexual functioning. While these lines of research suggest a role for the endocannabinoid system in female sexual functioning, no studies investigating the relationship between concentrations of endogenous cannabinoids (i.e., arachidonoylethanolamide [AEA] and 2-arachidonoylglycerol [2-AG]) and sexual functioning have been conducted in any species.
To measure circulating endocannabinoid concentrations in relation to subjective and physiological indices of sexual arousal in women (N = 21).
Serum endocannabinoid (AEA and 2-AG) concentrations were measured immediately prior to, and immediately following, viewing of neutral (control) and erotic (experimental) film stimuli in a repeated measures design. Physiological sexual arousal was measured via vaginal photoplethysmography. Subjective sexual arousal was measured both continuously and noncontinuously. Pearson's correlations were used to investigate the relationships between endocannabinoid concentrations and sexual arousal.
Changes in AEA and 2-AG concentrations from pre- to post-film and in relation to physiological and subjective indices of sexual arousal.
Results revealed a significant relationship between endocannabinoid concentrations and female sexual arousal, whereby increases in both physiological and subjective indices of sexual arousal were significantly associated with decreases in AEA, and increases in subjective indices of sexual arousal were significantly associated with decreases in 2-AG.
These findings support the hypothesis that the endocannabinoid system is involved in female sexual functioning, with implications for furthering understanding of the biological mechanisms underlying female sexual functioning.
Journal of Sexual Medicine 03/2012; 9(6):1588-601. · 3.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Research has examined the relationship between religiosity and sexuality but few studies have explored the mechanisms by which sexual variables are influenced by religiosity. The purpose of the present study was to investigate the role of sex guilt in the relationship between religiosity and sexual desire in women. Euro-Canadian (n = 178) and East Asian (n = 361) female university students completed a battery of questionnaires. Higher levels of religious fundamentalism, intrinsic religiosity and spirituality were associated with higher levels of sex guilt in both ethnic groups. Paranormal belief was not associated with sex guilt in either ethnic group. The Euro-Canadian women reported significantly higher levels of sexual desire and significantly less sex guilt than the East Asian women. Among the Euro-Canadian women, sex guilt mediated the relationships between spirituality and sexual desire, and fundamentalism and sexual desire; among the East Asian women, sex guilt mediated the relationships between spirituality and sexual desire, fundamentalism and sexual desire, and intrinsic religiosity and sexual desire. These findings suggest that sex guilt may be one mechanism by which religiosity affects sexual desire among women.
Archives of Sexual Behavior 03/2012; · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Growing evidence suggests that the endocannabinoid system is vital to ensuring normative maturation of the brain into adulthood. Endocannabinoid signaling contributes to guiding pro-neurogenic processes in early life and the development of neurotransmitter systems. Moreover, there is extensive evidence that recruitment of the endocannabinoid system is crucial in the regulation of neuroendocrine responses to stress via the hypothalamic-pituitary-adrenal (HPA) axis, and contributes to subsequent psychopathological consequences associated with emotionality and anxiety. These stress-induced physiological and behavioural sequelae are regulated by neural structures within the corticolimbic circuit, including the amygdala, hypothalamus, hippocampus, and prefrontal cortex. Based on evidence demonstrating endocannabinoid system involvement in both development and stress-induced changes in HPA axis function, it is reasonable to suggest that endocannabinoid signaling is an important mediator of interactions between stress responsivity and maturational stage. In this review, we discuss the ontogeny of the endocannabinoid system in the central nervous system, clinical and rodent models demonstrating short- and long-term effects of stress exposure, regulation of HPA axis responsivity by endocannabinoid signaling, as well as pharmacological and stress models indicating involvement of the endocannabinoid system in early post-natal and adolescent development on stress reactivity of the HPA, the corticolimbic system, and behaviour.
[Show abstract][Hide abstract] ABSTRACT: Depression is known to be a risk factor for cardiovascular diseases but the underlying mechanisms remain unclear. Since recent preclinical evidence suggests that endogenous agonists of cannabinoid receptors (endocannabinoids) are involved in both cardiovascular function and depression, we asked whether endocannabinoids correlated with either in humans.
Resting blood pressure and serum content of endocannabinoids in ambulatory, medication-free, female volunteers with depression (n = 28) and their age- and ethnicity-matched controls (n = 27) were measured. In females with depression, both diastolic and mean arterial blood pressures were positively correlated with serum contents of the endocannabinoids, N-arachidonylethanolamine (anandamide) and 2-arachidonoylglycerol. There was no correlation between blood pressure and endocannabinoids in control subjects. Furthermore, depressed women had significantly higher systolic blood pressure than control subjects. A larger body mass index was also found in depressed women, however, it was not significantly correlated with serum endocannabinoid contents.
This preliminary study raises the possibility that endocannabinoids play a role in blood pressure regulation in depressives with higher blood pressure, and suggests an interrelationship among endocannabinoids, depression and cardiovascular risk factors in women.
Lipids in Health and Disease 02/2012; 11:32. · 2.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The endocannabinoid system has recently emerged as a vital component of the stress response and is an appealing target for the treatment of mood and anxiety disorders. Additionally, corticolimbic endocannabinoid signaling is important for stress-induced regulation of emotional behavior. However, the mechanism by which this occurs remains elusive. Combining biochemical and behavioral analyses within the forced swim test, we examined whether stress-induced regulation of endocannabinoid signaling in the medial prefrontal cortex contributes to behavioral responses to stress, and whether these responses are dependent on serotonergic neurotransmission. Forced swim stress produced a rapid and pronounced reduction in medial prefrontal anandamide content, but had no effect on 2-arachidonoylglycerol content within this region. Local administration of the anandamide hydrolysis inhibitor URB597 (0.01μg) into the ventromedial region of the prefrontal cortex decreased passive coping responses and increased active behavioral strategies, a phenomenon which was blocked by local antagonism of the CB(1) receptor. Furthermore, local inhibition of anandamide hydrolysis within the medial PFC increased the firing rate of serotonergic neurons within the dorsal raphe, suggesting that prefrontal cortical endocannabinoid signaling may modulate stress coping behaviors through a regulation of serotonergic neurotransmission. Accordingly, serotonin depletion prevented the ability of inhibition of anandamide hydrolysis within the medial PFC to promote active stress coping responses. Collectively, these data argue that stress-induced changes in endocannabinoid signaling within the medial PFC modulate stress-coping behaviors through a regulation of serotonergic neurotransmission and provide a neuroanatomical framework by which we may understand the mechanisms subserving the antidepressant potential of the endocannabinoid system.
European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 02/2012; 22(9):664-71. · 3.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Endocannabinoids act as a major neuromodulatory system in a variety of physiological and behavioral functions. Three major lines of evidence suggest that the endocannabinoid system interacts with gonadal hormones. First, the endocannabinoid system is implicated in behaviors and physiological functions that are known to be regulated in part by gonadal hormones. Second, receptors and metabolic enzymes of the endocannabinoid system are localized extensively on structures in the hypothalamic-pituitary-gonadal axis. Third, changes in levels of gonadal hormones alter endocannabinoid signaling. Here we reviewed and summarized the current evidence regarding the interaction between the endocannabinoid system and androgens, estrogens, and progesterone. Overall, it appears that bidirectional interactions characterize the relationship between endocannabinoids and gonadal hormones, with endocannabinoids down-regulating hypothalamic-pituitary-gonadal activity and gonadal hormones modulating protein expression in the endocannabinoid system. An understanding of these interactions will have implications for elucidating the neuroendocrine mechanisms underlying a number of behavioral and physiological functions as well as potential pharmaceutical treatments for disorders of these functions.