Consummatory Components Research Articles

Antisocial behavior is associated with reduced frontoparietal activity to loss in a population-based sample of adolescents.

Adolescent antisocial behavior (AB) is a public health concern due to the high financial and social costs of AB on victims and perpetrators. Neural systems involved in reward and loss processing are thought to contribute to AB. However, investigations into these processes are limited: few have considered anticipatory and consummatory components of reward, response to loss, nor whether associations with AB may vary by level of callous-unemotional (CU) traits. A population-based community sample of 128 predominantly low-income youth (mean age = 15.9 years; 42% male) completed a monetary incentive delay task during fMRI. A multi-informant, multi-method latent variable approach was used to test associations between AB and neural response to reward and loss anticipation and outcome and whether CU traits moderated these associations. AB was not associated with neural response to reward but was associated with reduced frontoparietal activity during loss outcomes. This association was moderated by CU traits such that individuals with higher levels of AB and CU traits had the largest reductions in frontoparietal activity. Co-occurring AB and CU traits were also associated with increased precuneus response during loss anticipation. Findings indicate that AB is associated with reduced activity in brain regions involved in cognitive control, attention, and behavior modification during negative outcomes. Moreover, these reductions are most pronounced in youth with co-occurring CU traits. These findings have implications for understanding why adolescents involved in AB continue these behaviors despite severe negative consequences (e.g. incarceration).

Chronic Distress in Male Mice Impairs Motivation Compromising Both Effort and Reward Processing With Altered Anterior Insular Cortex and Basolateral Amygdala Neural Activation.

In humans and mammals, effort-based decision-making for monetary or food rewards paradigms contributes to the study of adaptive goal-directed behaviours acquired through reinforcement learning. Chronic distress modelled by repeated exposure to glucocorticoids in rodents induces suboptimal decision-making under uncertainty by impinging on instrumental acquisition and prompting negative valence behaviours. In order to further disentangle the motivational tenets of adaptive decision-making, this study addressed the consequences of enduring distress on relevant effort and reward-processing dimensions. Experimentally, appetitive and consummatory components of motivation were evaluated in adult C57BL/6JRj male mice experiencing chronic distress induced by oral corticosterone (CORT), using multiple complementary discrete behavioural tests. Behavioural data (from novelty suppressed feeding, operant effort-based choice, free feeding, and sucrose preference tasks) collectively show that behavioural initiation, effort allocation, and hedonic appreciation and valuation are altered in mice exposed to several weeks of oral CORT treatment. Additionally, data analysis from FosB immunohistochemical processing of postmortem brain samples highlights CORT-dependent dampening of neural activation in the anterior insular cortex (aIC) and basolateral amygdala (BLA), key telencephalic brain regions involved in appetitive and consummatory motivational processing. Combined, these results suggest that chronic distress-induced irregular aIC and BLA neural activations with reduced effort production and attenuated reward value processing during reinforcement-based instrumental learning could result in maladaptive decision-making under uncertainty. The current study further illustrates how effort and reward processing contribute to adjust the motivational threshold triggering goal-directed behaviours in versatile environments.

Lack of Associations Between C-Reactive Protein and Mood and Anxiety Symptoms in Adolescents.

Introduction: Increased peripheral inflammation has been consistently documented in both adult and pediatric depression. However, elevated levels of C-reactive protein (CRP), a nonspecific biomarker for inflammation, have been primarily reported in adults; whether CRP plays a similar role in adolescent depression has not been conclusively established. In our prior work, we identified relationships between CRP and reward neurocircuitry in adolescents with psychiatric symptoms (N = 64) but not with depressive symptoms. Extending this work, we sought to examine CRP across the full range of mood and anxiety symptom severity in a larger, clinically diverse cohort of psychotropic medication-free adolescents and healthy controls (HCs). Methods: Subjects were adolescents (N = 127, age: 15.17 ± 2.19 years, 78 female) with psychiatric symptoms (n = 96, including previous cohort of 64) and HC (n = 31). All completed a semi-structured psychiatric evaluation and dimensional assessments for depression, anxiety, anhedonia, and suicidality. Group-comparison and correlation analyses utilized nonparametric statistics controlled for body mass index, sex, and age at pFWE < 0.05. Results: No group differences were identified in CRP levels between the clinical cohort and HCs. In addition, correlations between CRP and clinical symptomatology were not significant in either the whole sample or the psychiatric group. Conclusions: We found that, unlike in adults, CRP was not associated with depressive symptoms. This suggests that inflammation in pediatric depression is more narrowly delimited at the onset of psychiatric symptoms and may only become systemic with chronicity.

Sexual Experience Influences Reproductive Behavior and Preoptic Androgen Receptors in Male Mice

Regenerative conduct in male rodents is comprised of expectant and consummatory components which are directed in the mind by tactile frameworks, reward circuits and chemical flagging. Gonadal steroids assume a vital part in the guideline of male sexual conduct by means of steroid receptors in the nerve center and preoptic region. Common examples of male conceptive conduct have been portrayed, anyway these are not fixed yet are regulated by grownup experience. The impacts of sexual experience on the quantity of cells communicating either androgen receptor (AR) or estrogen receptor alpha (ERα) in the essential cerebrum cores directing male sexual conduct was likewise estimated. Physically experienced male mice occupied with less sniffing of females prior to starting sexual conduct and displayed more limited latencies to mount and intromit, expanded recurrence of intromission, and expanded span of intromission comparative with mounting.

Effects of a glucagon-like peptide-1 analog on appetitive and consummatory behavior for rewarding and aversive gustatory stimuli in rats

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is essential for the regulation of food intake and approved for the treatment of type 2 diabetes mellitus and obesity in humans. More recently, GLP-1 has been investigated for its ability to modulate motivation for food and drugs. Reward behavior can be divided into two components: ‘motivational’ (i.e., approach and consummatory behaviors) and ‘affective’ (i.e., perceived palatability). Studies show that GLP-1 analogs reduce the motivation to approach and consume palatable food, but the impact on affective responding is unknown. Thus, the present study tested the effect of the GLP-1 analog, Exendin-4 (Ex-4), on the appetitive response to intraorally delivered sucrose and quinine. Results showed that Ex-4 (2.4ug/kg ip) failed to alter passive drip, appetitive reactions (i.e., mouth movements, tongue protrusions, and lateral tongue protrusions) or aversive reactions (i.e., gapes) to sucrose. Paw-licking, however, was significantly reduced by Ex-4. Treatment with Ex-4 also failed to influence passive drip to quinine, but increased the latency to gape and reduced the total number of gapes emitted. In addition, Ex-4 reduced intake of quinine in water restricted rats, but did not reduce conditioned aversion (i.e., gapes) or avoidance (i.e., reduced intake) of a LiCl-paired saccharin cue. Thus, while Ex-4 had no effect on a learned aversion, it reduced approach and ingestion of sweet and bitter solutions, while leaving the appetitive affective response to the sweet almost intact, and the aversive affective response to the bitter reduced. Treatment with Ex-4, then, differentially modulates appetitive and consummatory components of reward, depending on the valence of the stimulus and whether its valence is learned or innate.

A novel construct of anhedonia revealed in a Chinese sample via the Revised Physical and Social Anhedonia Scales

BackgroundAnhedonia is a core clinical symptom of mental disorders. The Revised Physical Anhedonia Scale (RPAS) and the Revised Social Anhedonia Scale (RSAS) have been applied in clinical and non-clinical samples since 1980s. However, the construct of a unified RPAS&RSAS for comprehensive measurement of anhedonia has never been explored. Therefore, the purpose of our study was to examine the factor structure of the unified RPAS&RSAS among undergraduates and clinical patients.MethodsA total of 3435 undergraduates from two universities and 294 clinical patients with mental disorders had completed the Chinese version of the RPAS and the RSAS. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were each conducted to reveal the constructs of the RPAS and the RSAS. CFA was used to evaluate first- and second-order models for the unified RPAS&RSAS in undergraduates and clinical patients. The internal consistency and test-retest reliability of the RPAS and the RSAS were also evaluated.ResultsEFA and CFA indicated 2-factor structures for RPAS and RSAS, with the factors being defined as anticipatory anhedonia and consummatory anhedonia. The second-order model of the unified RPAS&RSAS in the undergraduates and clinical patients both had satisfactory fit index values (Undergraduate sample: CFI = 0.901, TLI = 0.899, RMSEA = 0.055, SRMR = 0.086; Clinical sample: CFI = 0.922, TLI = 0.911, RMSEA = 0.052, SRMR = 0.078). The psychometric robustness of the RPAS&RSAS were confirmed by high internal consistency and test-retest reliability values.ConclusionsThe unified RPAS&RSAS with a second-order structure was confirmed in both undergraduates and clinical samples in Chinese. The construct of anhedonia was refreshed as covering physical and social domains, and each of them includes both anticipatory and consummatory components.

Effects of Glycine Receptors of the Medial Preoptic Nucleus on Sexual Behavior of Male Wistar Rats.

We studied the effect of bilateral microinjections of selective pharmacological agents modulating glycine receptor activity into the medial preoptic nucleus on sexual behavior of male Wistar rats. Application of the glycine receptor blocker strychnine (20 μM, 2 μl) led to a significant inhibition of both appetitive and consummatory components of sexual behavior, whereas stimulation with glycine (1 mM and 50 μM, 2 μl) had no significant effect.

M228. THE EFFECT OF SOCIALIZATION ON ANTICIPATORY AND CONSUMMATORY PLEASURE IN SCHIZOPHRENIA

BackgroundIndividuals with schizophrenia (SCZ) may have deficits in anticipatory but not consummatory components of pleasure, which are associated with negative symptoms including social anhedonia and reduced social motivation. In contrast, more general hedonic deficits in SCZ may be associated with depression. Much of the research on these distinct components of pleasure has focused on non-social stimuli, with less work on social pleasure. Although lab-based studies on social pleasure suggest that SCZ show deficits in both anticipatory and consummatory components of socialization, SCZ report a normative need for social affiliation as well as greater positive and less negative affect when with others than alone. We examined anticipatory and consummatory pleasure in SCZ in a social context using ecological momentary assessment (EMA), testing the hypotheses that: 1) clinician rated social anhedonia and amotivation are associated with decreases in anticipatory but not consummatory pleasure in daily life; 2) depression is associated with deficits in both anticipatory and consummatory pleasure in daily life; 3) current socialization is associated with both increased current pleasure and increased anticipation of future events.MethodsParticipants SCZ (N=63) were recruited as part of two separate EMA studies. The EMA questionnaire included questions assessing participants’ current socialization (with known others or alone/with strangers), happiness (as a measure of in-the-moment mood), current enjoyment of activities, and anticipated enjoyment, among other questions related to their responses to daily activities. Participants were prompted to complete the EMA survey four times per day for seven days. Clinical assessments of social motivation and social anhedonia using the Clinical Assessment Interview for Negative Symptoms and Beck’s Depression Inventory scores were also obtained in the lab.ResultsHierarchical linear modeling showed that social anhedonia and social amotivation predicted decreased anticipated enjoyment (social motivation β= -0.228 p =0.016; social anhedonia β= -0.203, p= 0.0287) when accounting for current socialization, but not decreased consummatory enjoyment or happiness. Depression predicted current happiness (β=-0.024, p= 0.0125), current enjoyment (β=-0.020, p= 0.004) and future enjoyment (β= -0.030, p <0.001). However, depression no longer predicted future enjoyment when accounting for current happiness. Both current happiness and current socialization predicted current enjoyment (happiness β= 0.37, p < 0.001; socialization β= 0.098, p= 0.0148). Current happiness also predicted anticipated enjoyment (β= 0.190, p< 0.001), while current socialization did not.DiscussionConsistent with our hypotheses, the current findings indicated differential relationships of depression and social anhedonia/motivation in SCZ to social consummatory versus anticipatory pleasure. Social amotivation and social anhedonia predicted decreased anticipated but not consummatory (i.e., current) pleasure when accounting for socialization. In contrast, current social experience predicted consummatory but not anticipatory pleasure, contrary to our hypothesis. Further, depression predicted current mood (happiness) and both consummatory and anticipatory pleasure, but the association with anticipatory pleasure was mediated by depression’s relationship to current happiness. These findings extend the work on non-social components of pleasure in SCZ to a social context and provide evidence that broader hedonic deficits are associated with mood, while negative symptoms are more specifically associated deficits in anticipatory pleasure.

Aberrant reward dynamics in trait anticipatory anhedonia

As a cardinal feature of several psychiatric disorders, anhedonia includes a consummatory component (deficits in hedonic response to rewards) and an anticipatory component (a reduced motivation to pursue them). Although being conceptualized as impairments of reward system, the neural characterization of reward processing in anhedonia is hampered by the enormous heterogeneity in the reward phase (‘wanting’ vs ‘liking’) and comorbidity (inherent to disease states). The current event-related potential (ERP) study examined the reward dynamics of anticipatory anhedonia in a non-clinical sample. Anticipatory and consummatory ERP components were assessed with a monetary incentive delay task in a high anticipatory anhedonia (HAA) group and a low anticipatory anhedonia (LAA) group. HAA vs LAA group showed a diminished reward-related speeding during behavioral performance and reported overall reduced positive affect during anticipation and receipt of outcomes. Importantly, neural dynamics underlying reward processing were negatively associated with anticipatory anhedonia across the anticipatory phase indexed by the contingent negative variation and the consummatory phase indexed by the feedback P3. Our results suggest that anticipatory anhedonia in non-clinical individuals is linked to a poor modulation during both anticipatory and consummatory phases of reward processing.

즐거움 경험의 예기적/소비적 요소가 무쾌감성 우울 증상에 미치는 영향

본 연구의 목적은 즐거움을 경험하는 능력의 감소로 폭넓게 정의되는 무쾌감성 우울(anhedonic depression)의 기저 특징을 탐색하고, 이에효과적으로 개입하기 위한 이론적인 기초를 제공하는 것이다. 이를 위해 즐거움 경험을 목표나 보상을 추구하는 접근 동기로서의 예기적즐거움과 목표 달성 이후 경험하는 소비적 즐거움이라는 두 가지 보상 처리 과정으로 구분한 뒤, 무쾌감성 우울과의 관련성을 밝히고자 하였다. 대학생 305명으로부터 수집한 자료를 통해 행동 활성화 체계 민감성과 심상화 능력, 마음챙김 주의자각, 무쾌감성 우울 간의 관계를분석한 결과, 예기적 즐거움은 행동 활성화 체계 민감성과 무쾌감성 우울, 심상화 능력과 무쾌감성 우울 간의 관계를 각각 완전매개 및 부분매개하는 것으로 나타났다. 또한 행동 활성화 체계 민감성의 영향을 통제하고도 심상화 능력은 예기적 즐거움에 유의미한 영향을 미치는 것으로 나타나, 무쾌감성 우울에 영향을 미치는 변인으로서 심상의 역할을 확인하였다. 마지막으로 소비적 즐거움은 마음챙김 주의자각과 무쾌감성 우울의 관계에서 조절변인 역할을 하는 것으로 나타났다. 이러한 연구 결과를 바탕으로 본 연구의 의의와 제한점에 대해 논의하였다.

The time course of incentive processing in anticipatory and consummatory anhedonia

BackgroundAnhedonia, the reduced capacity to experience pleasure, has long been regarded as a cardinal symptom in depression and schizophrenia. Recent evidence highlights that anhedonia is not a single construct but consists of an anticipatory component and a consummatory component, which is captured by the Temporal Experience of Pleasure Scale (TEPS). The current event-related potential study examined the electrophysiological underpinnings of anticipatory and consummatory aspects of anhedonia as assessed by the TEPS in a non-clinical sample. MethodsEEG was recorded during both anticipatory and consummatory phases of incentive processing in an anticipatory-anhedonia (ANT) group, a consummatory-anhedonia (CON) group, and a control (CNT) group selected from a large sample based on their TEPS scores. ResultsThe ANT relative to the CON group exhibited a reduced cue-P3 during the anticipatory phase, a less positive feedback-related negativity (FRN) and a blunted feedback P3 (fb-P3) during the consummatory phase. Moreover, correlation results revealed a dissociation between anticipatory and consummatory anhedonia, which occurred in an unexpected way such that higher levels of anticipatory anhedonia were associated with reduced fb-P3 amplitudes whereas higher levels of consummatory anhedonia with enhanced cue-P3 and FRN amplitudes. LimitationThe sample size for each group was relatively small. ConclusionsAnticipatory and consummatory anhedonia as measured by the TEPS might be driven by abnormal motivational salience, which was represented by the cue-P3 during the anticipatory phase and the FRN and fb-P3 during the consummatory phase of incentive processing.

The second-generation assessment scales: Brief negative symptom scale and clinical assessment interview for negative symptoms

The construct of negative symptoms has undergone significant changes since the introduction of first generation assessment scales, such as the Scale for the Assessment of Negative Symptoms or the Positive and Negative Syndrome Scale. Blunted affect, Alogia, Asociality, Anhedonia and Avolition are largely recognized as valid domains of the negative symptoms construct.Among the new assessment instruments, both the Brief Negative Symptom Scale (BNSS) and the Clinical Assessment Interview for Negative Symptoms (CAINS) are considered adequate in their coverage of the negative symptoms domains. They include the assessment of both behavior and internal experience for Anhedonia, Asociality and Avolition to avoid overlap with functional outcome measures, as well as consummatory and anticipatory components of anhedonia with an emphasis on the internal experience of pleasure.Strengths and limitations of these new assessment instruments will be reviewed in the light of some existing challenges, such as the distinction between primary and secondary negative symptoms and development of innovative treatments.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Hormone replacement with 17β-estradiol plus dihydrotestosterone restores male sexual behavior in rats treated neonatally with clomipramine

Male sexual behavior (MSB) in rodents, in both its consummatory and motivational components, is regulated by hormones such as testosterone, 17β-estradiol and 5-α-dihydrotestosterone. In experiments, neonatal treatment with clomipramine (CMI; a serotonin reuptake inhibitor) reproduces some of the signs of depression in adult age, including reduced sexual behavior manifested in a lower percentage of subjects that mount, intromit and ejaculate, although their testosterone levels were not altered. However, the effect of this treatment on estrogen levels and the consequences of hormone substitution using 17β-estradiol and 5-α-dihydrotestosterone on the expression of male sexual behavior are still unknown. Therefore, the objective of the present study was to analyze the effect of neonatal treatment with CMI on plasma testosterone and 17β-estradiol levels, and the role of testosterone, 17β-estradiol and 5-α-dihydrotestosterone in altering the consummatory and motivational components of sexual behavior in male rats. To this end, it analyzed the copulatory parameters and sexual incentive motivation (SIM) of rats treated with CMI under two conditions: basal and post-hormone replacements. Neonatal treatment with CMI did not affect plasma testosterone or 17β-estradiol concentrations, but did decrease both the consummatory component and sexual motivation according to the results of the SIM test. These aspects were recovered after administering 17β-estradiol +5-α-dihydrotestosterone, but not testosterone.

Distinct neuroendocrine mechanisms control neural activity underlying sex differences in sexual motivation and performance.

Sexual behavior can be usefully parsed into an appetitive and a consummatory component. Both appetitive and consummatory male-typical sexual behaviors (respectively, ASB and CSB) are activated in male Japanese quail by testosterone (T) acting in the medial preoptic nucleus (POM), but never observed in females. This sex difference is based on a demasculinization (=organizational effect) by estradiol during embryonic life for CSB, but a differential activation by T in adulthood for ASB. Males expressing rhythmic cloacal sphincter movements (RCSMs; a form of ASB) or allowed to copulate display increased Fos expression in POM. We investigated Fos brain responses in females exposed to behavioral tests after various endocrine treatments. T-treated females displayed RCSM, but never copulated when exposed to another female. Accordingly they showed an increased Fos expression in POM after ASB but not CSB tests. Females treated with the aromatase inhibitor Vorozole in ovo and T in adulthood displayed both male-typical ASB and CSB, and Fos expression in POM was increased after both types of tests. Thus, the neural circuit mediating ASB is present or can develop in both sexes, but is inactive in females unless they are exposed to exogenous T. In contrast, the neural mechanism mediating CSB is not normally present in females, but can be preserved by blocking the embryonic production of estrogens. Overall these data confirm the difference in endocrine controls and probably neural mechanisms supporting ASB and CSB in quail, and highlight the complexity of mechanisms underlying sexual differentiation of behavior.

Rapid effects of 17β-estradiol on male copulatory behaviors are not elicited by the novel membrane active estrogenic compound STX.

Estrogens have been shown to rapidly promote male copulatory behaviors with a time-course that suggests rapid signaling events are involved. The present study tested the hypothesis that estrogen acts through a novel Gq protein-coupled membrane estrogen receptor (ER). Thus, either estradiol (E2), STX (a diphenylacrylamide compound that selectively activates a membrane ER pathway), or vehicle were administered acutely to castrated male rats that bore subcutaneous (sc) dihydrotestosterone implants to maintain genital sensitivity. Appetitive (level changes, genital investigation) and consummatory (mounts, intromissions, ejaculations) components of male sexual behavior were measured in a bilevel testing apparatus. Testing showed that E2 treatment promoted olfactory and mounting behaviors, but had no effect on motivation as measured by anticipatory level changes. STX treatment showed no effect on either component of male sexual behavior. These results support previous results that showed that E2 can rapidly affect male sexual behaviors but fail to support a role for the specific membrane-initiated pathway activated by STX.

Brain structures involved in the sexual behaviour of Ile de France rams with different sexual preferences and levels of sexual activity

Using Fos, as a marker, we analysed the brain structures of rams, with different libidos or sexual preferences that had been activated by contact with males or females. Ile de France rams aged from 1.5 to 7 years were used. Fos immunoreactivity (Fos IR) was analysed in rams with high (HL) or low libido (LL) after 90 min of direct contact with females (HL DirF n = 7 or LL DirF n = 7) or in rams of high libido having indirect contact through a fence, with females (HL IndF n = 6) or males (HL IndM n = 5) and finally, in males who preferred other males as partners by indirect contact through a fence with males (MO IndM n = 4). Direct or indirect contact with a preferred sexual partner (LL DirF, HL Dir F, HL IndF, MO IndM) induced the appearance of Fos-IR cells in several diencephalic and cortical structures. Conversely, indirect contact with males did not induce Fos-IR in males interested in females (HL IndM). In the medial preoptic area (MPOA), the paraventricular nucleus and the medial bed nucleus of the stria terminalis the cell density of Fos IR cells was higher in HL Dir F than in LL DirF suggesting involvement in sexual motivation whereas only the MPOA seemed involved the consummatory component of sexual behaviour (Fos IR density HL DirF > HL IndF). The enthorinal cortex was the only structure specifically activated by males attracted to other males (Fos IR density MO IndM > HL IndM) whereas Fos IR density did not differ between the HL IndF and HL IndM groups.

Opposite roles of dopamine and orexin in quinpirole-induced excessive drinking: a rat model of psychotic polydipsia

Repeated administration of the dopamine D2/D3 agonist quinpirole (QNP) progressively increases non-regulatory water intake. This effect may model psychotic polydipsia, a potentially fatal but poorly understood condition. The growing evidence for a role of orexin in mediating arousal and cognition has linked this peptide to schizophrenia, hence we examined whether manipulations of dopaminergic and orexinergic systems, as well as of setting, would further characterize the model. Water intake was measured in rats sequentially tested in home and then operant conditioning setting, with chronic administration of D2 antagonist haloperidol (Hal) prior to QNP treatment. A group of rats similarly treated was also assessed for orexin A (OxA) expression in the cortex. Finally, the effect of the orexin-1 receptor antagonist SB-334867 on QNP-induced polydipsia was evaluated. In rats made polydipsic by QNP the amount of water drank during the first 4 h was strongly correlated with the degree of dissociation between appetitive and consummatory components of drinking behavior in the following hour of operant access to water. Hal 0.2 mg/kg prevented both polydipsia and the dissociation, while 0.1 mg/kg only blocked the dissociation. Chronic QNP treatment increased, in a Hal-reversible way, OxA expression in the somatosensory cortex (SI). Moreover, pretreatment with SB-334867 sped up and potentiated QNP-induced polydipsia. Results disclose compulsive components in QNP-induced polydipsia that are mediated by dopamine D2 receptors. QNP also regulates OxA expression in the SI, while the block of orexin-1 receptors enhances QNP-induced polydipsia. We suggest that dopamine and OxA play opposite roles in QNP-induced polydipsia.

Anticipatory and consummatory components of the experience of pleasure in schizophrenia: Cross-cultural validation and extension

This study examined anticipatory and consummatory pleasure in schizophrenia patients with and without negative symptoms. Negative symptom patients experienced less anticipatory pleasure than non-negative symptom patients; only one facet of consummatory pleasure was unaffected in negative schizophrenia. Greater pleasure deficits were correlated with more severe positive and negative symptoms.

Behavioral Effects of Brain‐derived Estrogens in Birds

In birds as in other vertebrates, estrogens produced in the brain by aromatization of testosterone have widespread effects on behavior. Research conducted with male Japanese quail demonstrates that effects of brain estrogens on all aspects of sexual behavior, including appetitive and consummatory components as well as learned aspects, can be divided into two main classes based on their time course. First, estrogens via binding to estrogen receptors regulate the transcription of a variety of genes involved primarily in neurotransmission. These neurochemical effects ultimately result in the activation of male copulatory behavior after a latency of a few days. Correlatively, testosterone and its aromatized metabolites increase the transcription of the aromatase mRNA, resulting in an increased concentration and activity of the enzyme that actually precedes behavioral activation. Second, recent studies with quail demonstrate that brain aromatase activity can also be modulated within minutes by phosphorylation processes regulated by changes in intracellular calcium concentration, such as those associated with glutamatergic neurotransmission. The rapid upregulations or downregulations of brain estrogen concentration (presumably resulting from these changes in aromatase activity) affect, by nongenomic mechanisms with relatively short latencies (frequency increases or decreases respectively within 10-15 min), the expression of male sexual behavior in quail and also in rodents. Brain estrogens thus affect behavior on different time scales by genomic and nongenomic mechanisms similar to those of a hormone or a neurotransmitter.

Improved sexual behavior in male rats treated with a Chinese herbal extract: hormonal and neuronal implications

To investigate the influence of an extract obtained from five Chinese medicinal plants on sexual behavior of adult male rats. The extract was administered at doses of 30, 60 and 120 mg/kg by oral gavage, acutely (one time, 45 min before mating test) or subchronically (daily for 10 days) in sexually potent and sexually sluggish/impotent rats. Sexual behavior, serum levels of luteinizing hormone (LH) and testosterone (T) were evaluated in treated rats and compared with controls receiving vehicle. The effect of the extract on central dopaminergic neurotransmission was assessed in the nucleus accumbens using a microdialysis technique. In sexually potent rats, both acute and subchronic treatment with the extract dosed at 30 and 60 mg/kg reduced mount latency and intromission latency. In sluggish/impotent rats, the acutely administered extract at the dose of 60 mg/kg shortened ejaculation latency, whereas subchronically administered at the doses of 30 and 60 mg/kg, reduced mount, intromission and ejaculation latencies, increasing also the percentage of mounting and ejaculating rats. The extract dosed at 60 mg/kg significantly increased LH and T following acute and subchronic administration and increased 3,4-dihydroxyphenylacetic acid levels in the nucleus accumbens, 30 min after the acute administration. The improvement in both appetitive and consummatory components of sexual behavior observed in male rats treated with the extract could be ascribed to increased serum T level in parallel with the activation of the central dopaminergic system.