Daylight photodynamic therapy for prevention of new actinic keratosis and keratinocyte carcinomas in organ transplants. A cryotherapy-controlled randomized clinical trial

BACKGROUND

Organ transplant recipients (OTR) have a higher risk of actinic keratosis (AK) and keratinocyte carcinomas (KC). There are no clinical trials assessing the effectiveness of daylight photodynamic therapy (DPDT) to prevent new AK and KC in OTR.

OBJECTIVES

To determine whether repeated treatments of field cancerization with DPDT are effective in preventing new AK and KC in OTR.

METHODS

A randomized, intra-subject controlled, evaluator-blind, split-face and/or scalp trial, from April 2016 to October 2018. Participants were OTR older than 18 years, 1-year posttransplant, with at least 5 AK on each hemi-face/hemi-scalp. One side received six field treatments with DPDT: two sessions 15 days apart at baseline, two at 3 months and two at 9 months after baseline. Control side received lesion-directed treatment with cryotherapy (double freeze-thaw) at baseline, 3 and 9 months. Total number of lesions (AK and KC) at 21 months, number of new AK and KC at 3, 9, 15 and 21 months and treatment preferences were analysed.

RESULTS

Of 24 men included, 23 were analysed at 3 months; and 21, at 9, 15 and 21 months. Mean (SD) age was 69.8 years (9.2). The total number of lesions at 21 months was 4.7 (4.3) for DPDT and 5.8 (5.0) for control side; P = 0.09. DPDT showed significantly lower means [SD] of new lesions compared to control side at 3 months (4.2 [3.4] vs. 6.8 [4.8]; P < 0.001), 9 months (3.0 [3.3] vs. 4.3 [3.4]; P = 0.04) and 15 months (3.0 [4.6] vs. 4.8 [5.0]; P = 0.02), and non-significant at 21 months (3.7 [3.5] vs. 5.0 [4.5]; P = 0.06). Most participants preferred DPDT.

CONCLUSION

DPDT showed potential effectiveness in preventing new AK and KC in OTR by consecutive treatments of field cancerization. The preference for DPDT could facilitate adherence to the long-term treatment necessary in these patients.

Double-checking emotions: Valence and emotion category in contextual integration of facial expressions of emotion

Faces showing happy, angry or fearful expressions were presented in emotionally congruent or incongruent situational contexts (short sentences describing events that would usually provoke happiness, anger or fear). The participants were assigned the task of judging whether the expression was appropriate or not to the context (congruency judgment task). Effects of emotional congruency were observed at both the behavioral and electrophysiological levels. Behavioral results showed evidence of congruency effects based on specific emotion content (e.g., less accurate and slower responses to fear faces in angry contexts). Event-related-potentials (ERP) results also showed emotional congruency effects at different post-stimulus onset latencies, beginning with the face-sensitive N170 component. An effect of emotional congruency was also shown on the N400 component that is typically sensitive to semantic congruency. Finally, a late positive potential (LPP), appearing at 450-650 ms post-stimulus onset showed a complex pattern of effects with modulations driven by the different combinations of contexts and target expressions. These results are interpreted in terms of a double process of valence and emotion checking that is supposed to underlie affective processing and contextual integration of facial expressions of emotions.

Effects of affective and emotional congruency on facial expression processing under different task demands

Contextual influences on responses to facial expressions of emotion were studied using a context-target paradigm that allowed distinguishing the effects of affective congruency (context and target of same/different valence: positive or negative) and emotional congruency (context and target representing the same/different emotion: anger, fear, happiness). Sentences describing anger, fear or happiness-inducing events and faces expressing each of these emotions were used as contexts and targets, respectively. While between-valence comparisons (context and target of similar/different valence) revealed affective congruency effects, within-valence comparisons (context and target of similar valence and same/different emotion) revealed emotional congruency effects. In Experiment 1 no evidence of emotional congruency and limited evidence of affective congruency were found with an evaluative task. In Experiment 2 effects of both affective and emotional congruency were observed with an emotion recognition task. In this case, angry and fearful faces were recognized faster in emotionally congruent contexts. In Experiment 3 the participants were asked explicitly to judge the emotional congruency of the target faces. Emotional congruency effects were again found, with faster judgments of angry and fearful faces in the corresponding emotional contexts. Moreover, judgments of angry expressions were faster and more accurate in happy than in anger contexts. Thus, participants found easier to decide that angry faces did not match a happy context than to judge that they did match an anger context. These results suggest that there are differences in the way that facial expressions of positive and negative emotions are discriminated and integrated with their contexts. Specifically, compared to positive expressions, contextual integration of negative expressions seems to require a double check of the valence and the specific emotion category of the expression and the context.

Evaluative and Psychophysiological Responses to Short Film Clips of Different Emotional Content

Abstract. The study presents self-report and psychophysiological data obtained in response to short film clips representing scenes related to different emotions. This was done in order to obtain evidence on the structure of positive and negative affective states following a combined dimensional/categorical approach to emotion and based on responses to stimuli that are more realistic than the static pictures usually employed in the study of emotion. Affective ratings and self-report measures showed a differential structure of the response to positive and negative films (Experiment 1). While all negative films were rated as low in valence and high in arousal, positive films were differentiated into arousing (happy and pleasure contents) and de-arousing (relax contents) categories. A more complex pattern emerged in Experiment 2, using two psychophysiological measures that are differentially sensitive to the main affective dimensions of valence and arousal, skin conductance response (SCR) and facial electromyography (fEMG). First, high arousal positive and negative films produced larger skin conductance responses. Second, fEMG measures showed differentiated response patterns within the positive and negative film categories. Within the positive category, happy and relaxing films had opposed effects, with happy films increasing and relax films decreasing activity over the zygomaticus muscle region. In the case of negative films, only those eliciting disgust produced a differentiated pattern of fEMG activity characterized by large corrugator responses and a modest increase of zygomatic responses. These results are discussed in relation to the adequacy of the dimensional and categorical approaches to emotion, the usefulness of combining subjective and psychophysiological measures, and the advantages of using realistic, dynamic stimuli for the study of emotion.

Facial affect recognition in early and late-stage schizophrenia patients

Prior studies have shown deficits in social cognition and emotion perception in first-episode psychosis (FEP) and multi-episode schizophrenia (MES) patients. These studies compared patients at different stages of the illness with only a single control group which differed in age from at least one clinical group. The present study provides new evidence of a differential pattern of deficit in facial affect recognition in FEP and MES patients using a double age-matched control design. Compared to their controls, FEP patients only showed impaired recognition of fearful faces (p=.007). In contrast to this, the MES patients showed a more generalized deficit compared to their age-matched controls, with impaired recognition of angry, sad and fearful faces (ps<.01) and an increased misattribution of emotional meaning to neutral faces. PANSS scores of FEP patients on Depressed factor correlated positively with the accuracy to recognize fearful expressions (r=.473). For the MES group fear recognition correlated positively with negative PANSS factor (r=.498) and recognition of sad and neutral expressions was inversely correlated with disorganized PANSS factor (r=-.461 and r=-.541, respectively). These results provide evidence that a generalized impairment of affect recognition is observed in advanced-stage patients and is not characteristic of the early stages of schizophrenia. Moreover, the finding that anomalous attribution of emotional meaning to neutral faces is observed only in MES patients suggests that an increased attribution of salience to social stimuli is a characteristic of social cognition in advanced stages of the disorder.

Anxiety and Depression in European Immigrants in Africa: Spaniards in South Africa

Introduction

It is easy to find texts, in scientific literature, studying the adaptation of immigrants from developing countries in western countries. However, in these globalization times that we are living, few are the studies performed on members from developed countries emigrating to the third world.

Objectives/Aims

To evaluate the factors predisposing to the onset of anxiety or depression symptoms in Spanish immigrants living in South Africa.

Methods

This is an exploratory study with a sample of 51 Spanish residents in South Africa between 24 and 57 years (44% male, 56% female), 44% of which were living there for more than two years. An online survey was administered, collecting data related to reasons and conditions for their moving to the country and traumatic events living during the stay. For the screening of depression and anxiety symptoms Hopkins Symptom Scale (HSCL-25) was used. Finally, we carried about several analysis using Chi2 test. For statistical analysis SPSS was utilized.

Results

Thirty percent of the sample showed positive scores on anxiety symptoms scale, and 24% scored positive for depression. Job related items as being unemployed (P < 0.001) was associated to symptoms of depression. Insecurity/violence (P < 0.021) and race discrimination (P < 0.009) were the main factors related to anxiety symptoms.

Conclusions

Factor related to employment, security and discrimination, has been significantly associated to the onset of anxiety and depression symptoms. Other factors related to the moving to the country or social relationships have shown no relations. More studies are needed to provide information about adaptation and factors related to mental health in Occidental immigrants in developing countries.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A psychiatrist's poll on their methods to treat schizoaffective disorder

Introduction

Schizoaffective disorder (SAD) is the second most frequent psychotic disorder after schizophrenia. There is a relative scarcity of specific studies looking into SAD treatment and evidence on drug treatment of SAD is patchy. We aimed to study naturalistically, interviewing psychiatrists systematically, what do they think is most useful in SAD treatment.

Objectives/aims

To know the actual management of SAD in real clinical practice and provided data for effective clinical studies.

Methods

We administered an online poll to 65 psychiatrists (52% male, 48% female), 75% of which described themselves as having a holistic background. The poll was completed using a Google doc's questionnaire. The three main questions made were:

– what is your first treatment choice for SAD;

– do you tend to use mono- vs. poly-therapy;

– provide a level of utility for each drug between 1 (little use) to 4 (maximum use).

Results

Atypical antipsychotics were considered the most common first choice in the treatment of SAD according to 66.2% of psychiatrists. The second most selected first choice answer was combining drugs and psychotherapy, which was answered by 20% of the sample. Monotherapy was preferred (60%) to polytherapy (40%). Finally, the most useful drug for SAD according to the sample was aripiprazole followed by mood stabilizers, olanzapine and paliperidone.

Conclusions

Real practice in SAD treatment may differ grossly to what is advocated for in clinical guidelines and seem to also deviate from officially approved indications of some drugs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Following the time course of face gender and expression processing: a task-dependent ERP study

The effects of task demands and the interaction between gender and expression in face perception were studied using event-related potentials (ERPs). Participants performed three different tasks with male and female faces that were emotionally inexpressive or that showed happy or angry expressions. In two of the tasks (gender and expression categorization) facial properties were task-relevant while in a third task (symbol discrimination) facial information was irrelevant. Effects of expression were observed on the visual P100 component under all task conditions, suggesting the operation of an automatic process that is not influenced by task demands. The earliest interaction between expression and gender was observed later in the face-sensitive N170 component. This component showed differential modulations by specific combinations of gender and expression (e.g., angry male vs. angry female faces). Main effects of expression and task were observed in a later occipito-temporal component peaking around 230 ms post-stimulus onset (EPN or early posterior negativity). Less positive amplitudes in the presence of angry faces and during performance of the gender and expression tasks were observed. Finally, task demands also modulated a positive component peaking around 400 ms (LPC, or late positive complex) that showed enhanced amplitude for the gender task. The pattern of results obtained here adds new evidence about the sequence of operations involved in face processing and the interaction of facial properties (gender and expression) in response to different task demands.

Learning about Faces: Effects of Trustworthiness on Affective Evaluation

The results of two studies on the relationship between evaluations of trustworthiness, valence and arousal of faces are reported. In Experiment 1, valence and trustworthiness judgments of faces were positively correlated, while arousal was negatively correlated with both trustworthiness and valence. In Experiment 2, learning about faces based on their emotional expression and the extent to which this learning is influenced by perceived trustworthiness was investigated. Neutral faces of different models differing in trustworthiness were repeatedly associated with happy or with angry expressions and the participants were asked to categorize each neutral face as belonging to a “friend” or to an “enemy” based on these associations. Four pairing conditions were defined in terms of the congruency between trustworthiness level and expression: Trustworthy-congruent, trustworthy-incongruent, untrustworthy-congruent and untrustworthy-incongruent. Categorization accuracy during the learning phase and face evaluation after learning were measured. During learning, participants learned to categorize with similar efficiency trustworthy and untrustworthy faces as friends or enemies and thus no effects of congruency were found. In the evaluation phase, faces of enemies were rated as more negative and arousing than those of friends, thus showing that learning was effective to change the affective value of the faces. However, faces of untrustworthy models were still judged on average more negative and arousing than those of trustworthy ones. In conclusion, although face trustworthiness did not influence learning of associations between faces and positive or negative social information it did have a significant influence on face evaluation that was manifest even after that learning.

Modulation of Early Perceptual Processing by Emotional Expression and Acquired Valence of Faces

Modulation of early perceptual processing by emotional expression and the affective valence of faces was explored in an event-related potential (ERP) study. An associative procedure was used where different neutral faces changed to happy, to angry or, in a control condition, stayed the same. Based on these changes in expression, participants had then to identify each neutral face as belonging to a friendly, hostile, or neutral individual. ERP measures revealed modulations at occipital-temporal sites of the P100 and N170 components by both the emotional expression and the valence of the associated neutral faces. The early posterior negativity (EPN) component, however, was only sensitive to emotional expression. These results are consistent with previous findings showing that emotional expression influences face perception since early stages of visual processing and provide new evidence that this influence can also be transferred to neutral faces through associative learning.

Photodynamic therapy for actinic keratosis in organ transplant patients

BACKGROUND

The incidence of actinic keratoses (AK) and non-melanoma skin cancer (NMSC) in organ transplant recipients (OTRs) is significantly higher than in immunocompetent patients. Rates of progression and recurrence following treatment are higher too, in part due to the effects of the immunosuppressant drugs. Conventional therapies for AK, using curettage, cryotherapy, surgical excision, topical therapies and photodynamic therapy (PDT), are often less effective, and may be inappropriate, for treating the greater numbers and extent of lesions in OTRs. Moreover, there are no specific protocols for treating this patient population that take into account the need for more frequent treatment and the increased pain associated with treating larger areas.

OBJECTIVES

Recently, a pan-European group of dermatologists with expertise in this area met to share current best practice in PDT for the treatment of AK in OTRs.

METHODS

The group identified areas where PDT currently is not meeting the needs of these patients and discussed how these gaps might be addressed.

RESULTS/CONCLUSIONS

This position article summarizes those discussions and makes recommendations concerning a standardized protocol for treating OTRs, for a large randomized controlled trial to provide robust data on safety, efficacy and optimal pain control, and to provide pharmaco-economics data that can be used to support extended reimbursement in this patient group. The authors also recommend a second clinical trial to further investigate induced immunosuppression with PDT in healthy volunteers.

Quantitative profiling of in vivo generated cisplatin-DNA adducts using different isotope dilution strategies

Platinum compounds are the major group of metal-based chemotherapeutic drug used in current practice and still a topic of intense investigation. The relative contribution of structurally defined cisplatin adducts with DNA to induce apoptosis and the cellular processing of these lesions is still poorly understood mostly due to the lack of sensitive and accurate analytical tools for in vivo studies. In this regard, two novel sensitive and selective strategies are proposed here to quantify cisplatin-DNA adducts generated in Drosophila melanogaster larvae and in head and neck squamous cell carcinoma cultures. The methods involve the isolation and enzymatic digestion of the DNA in the samples exposed to cisplatin and further quantification by high-performance liquid chromatography with inductively coupled plasma mass spectrometric detection (HPLC-ICPMS). Two different strategies, based on isotope dilution analysis (IDA), have been attempted and evaluated for quantification: species-unspecific (the postcolumn addition of a 194Pt-enriched solution) and the species-specific (by means of a synthesized isotopically enriched cisplatin (194Pt) adduct). For the second approach, the synthesis and characterization of the cisplatin adduct in a custom oligonucleotide containing the sequence (5'-TCCGGTCC-3') was necessary. The adducted oligo was then added to the DNA samples either before or after enzymatic hydrolysis. The results obtained using these two strategies (mixing before and after enzymatic treatment) permit to address, quantitatively, the column recoveries as well as the efficiency of the enzymatic hydrolysis. Species-specific spiking before enzymatic digestion provided accurate and precise analytical results to clearly differentiate between Drosophila samples and carcinoma cell cultures exposed to different cisplatin concentrations.

Angiogenic and prothrombotic markers in extensive slow-flow vascular malformations: implications for antiangiogenic/antithrombotic strategies

BACKGROUND

Venous and combined malformations are slow-flow haemodynamically inactive lesions that are present at birth and worsen slowly with advancing age, showing no tendency towards involution. The pathogenesis of vascular anomalies has not been fully elucidated, but their formation and progression are closely related to angiogenesis. Localized intravascular coagulation associated with venous or combined malformations is characterized by low fibrinogen, high D-dimers, and normal platelet count.

OBJECTIVES

To assess the relationship of angiogenic factors with prothrombotic and endothelial damage/dysfunction markers in patients with extensive slow-flow vascular malformations.

METHODS

A 2-year study (2005-2007) included 31 consecutive patients with extensive slow-flow vascular malformations from one centre.

RESULTS

Serum levels of the endothelial receptor tyrosine kinase TIE-2, matrix metalloproteinase (MMP)-9 and angiopoietin (Ang)-2 and plasma levels of D-dimer, plasminogen activator inhibitor type 1 (PAI-1), tissue-type plasminogen activator and von Willebrand factor (vWf) were significantly increased in patients compared with healthy controls, whereas serum levels of vascular endothelial growth factor (VEGF)-C, VEGF-D, MMP-2, Ang-1, platelet-derived growth factor (PDGF)-AB and PDGF-BB were significantly decreased in patients compared with controls. A strong positive correlation was present between Ang-1 and PDGF-AB levels (r = 0.63, P < 0.001), between PDGF-AB and PDGF-BB levels (r = 0.67, P < 0.001), and between fibrinogen and PAI-1 levels (r = 0.41, P = 0.031). A strong negative correlation was present between Ang-1 and vWf levels (r = -0.48, P = 0.006), between D-dimer and fibrinogen levels (r = -0.71, P < 0.001), and between PDGF-AB and vWf levels (r = -0.42, P = 0.017).

CONCLUSIONS

These findings suggest that angiogenic, coagulation and endothelial damage/dysfunction markers are possibly linked in pathogenesis of extensive slow-flow vascular malformations, and might have therapeutic implications.

[Prolonged complete clinical remission in patients with severe pemphigus vulgaris after cycles of intravenous cyclophosphamide]

BACKGROUND

Corticosteroids are the systemic treatment of choice in patients with pemphigus vulgaris, but chronic administration is associated with side effects. Intravenous treatment with cyclophosphamide can improve the clinical signs of pemphigus vulgaris.

MATERIAL AND METHODS

We prospectively studied 8 patients diagnosed with pemphigus vulgaris. Six of these had mucocutaneous pemphigus vulgaris and 2 had mucosal pemphigus vulgaris. Treatment consisted of 10 cycles of cyclophosphamide at a dose of 10-15 mg/kg separated by 15 days, while maintaining the initial corticosteroid and immunosuppressant dose. Clinical efficacy was assessed and the anti-epidermal intercellular substance (EIS) and anti-desmoglein (DSG) 3 and 1 antibody titers were monitored (by indirect immunofluorescence and enzyme-linked immunosorbent assay, respectively).

RESULTS

All patients with pemphigus vulgaris responded excellently to treatment. Five of the 8 patients achieved complete remission of pemphigus lesions after 10 cycles of cyclophosphamide. In the other 3 patients, the skin lesions disappeared a few weeks after the last cycle of cyclophosphamide. A substantial reduction in immuno suppressant dose was possible in all patients. Furthermore, an improved immunologic response was observed in all cases after cyclophosphamide treatment, with decreased anti-DSG1 and anti-DSG3 antibody titers and well as decreased circulating anti-EIS antibody titers. During the mean 15.1 month follow-up (range, 1-25 months), no new lesions appeared and no side effects of cyclophosphamide therapy were reported.

CONCLUSIONS

Fortnightly cycles of intravenous cyclophosphamide may be a useful therapeutic option in patients with severe pemphigus vulgaris. A reduction of corticosteroid dose was possible with this therapeutic approach and the cumulative cyclophosphamide dose was lower than with daily oral administration. Our findings also show that the therapeutic approach induces clinical and immunologic remission in most patients.

[Repigmentation of gray hair after thyroid hormone treatment]

BACKGROUND AND OBJECTIVES

Darkening of gray and white hairs occurred in 2 patients with increased exogenous triiodothyronine (T3) due to treatment of myxedema coma in one case and iatrogenic hyperthyroidism in the other. We hypothesized that thyroid hormone may affect the homeostasis of hair follicles. To test our hypothesis and investigate the influence of thyroid hormone on the hair cycle, we used an in vivo murine model and an in vitro model based on culture of follicular units.

METHODS

We used the standard C57BL/6 murine model of the hair cycle. T3 (0.5 microg) dissolved in ethanol was applied topically once daily for 10 days to a depilated area in the telogen phase on the backs of the mice. Follicular units, obtained from hair transplant interventions, were cultured in vitro with different concentrations of T3.

RESULTS

On day 5, all T3-treated mice entered the anagen phase, whereas the anagen phase started spontaneously in control mice on day 9, and not until day 15 had all controls entered this phase. In the in vitro experiment, follicular units treated with 100 nmol/L T3 grew significantly larger compared to the control group.

CONCLUSIONS

These data suggest that follicles in the telogen phase can be induced to enter the anagen phase by the topical application of T3. This thyroid hormone may reverse graying of the terminal hair. In the in vitro experiments, T3 stimulated hair shaft growth. Follicular melanocytes may be the target cell for these actions.

Extinction of a saccharin—lithium association: Assessment by consumption and taste reactivity

Extinction of a conditioned palatability shift preceded extinction of conditioned taste avoidance whether rats were tested using a within-subjects design or a between-subjects design. In each of two experiments, consumption of 0.1% saccharin was paired with either 20 ml/kg of 0.15 M LiCl or equi-volume physiological saline on a single trial. In Experiment 1, on each of 10 extinction trials, rats were given a taste reactivity test immediately prior to a consumption test. In Experiment 2, half of the rats were extinguished by taste reactivity testing and half of the rats were extinguished by a consumption test on each of 10 extinction trials. In both experiments, the aversive reactions of gaping and passive dripping were extinguished in a single trial and the suppression of ingestive reactions was extinguished in 2 trials; however, extinction of taste avoidance required 4-5 trials. These results suggest that rats continue to avoid a lithium-paired flavor even when they do not have an aversion to the taste.

Release of ovarian progesterone during the rat oestrous cycle by ganglionic cholinergic influence: the role of norepinephrine

The coeliac ganglion neurons, whose axons constitute the superior ovarian nerve (SON), contain cholinergic receptors. The aim of this work was to study the effect of cholinergic agents added to the coeliac ganglion on the release of ovarian progesterone in the coeliac ganglion-SON-ovary in vitro system. We also analyzed the release of norepinephrine in the ovarian compartment and its possible relationship with the release of progesterone. After the addition of cholinergic agents in the ganglion compartment, progesterone release was determined by radioimmuneassay (RIA) and norepinephrine by catecholamine assay (HPLC). The release of progesterone and norepinephrine in the ovary compartment was studied during period of 180 min in pre-oestrus (PE), oestrus (E), dioestrus day 1 (D1) and dioestrus day 2 (D2) rats. The most relevant results concerning the action of acetylcholine were found on PE and dioestrus. On PE, the pre-ovulatory peak of progesterone, which is known to respond to the endocrine action, was not modified by neural effect of acetylcholine in our scheme. On the other hand, the progesterone peak occurs in the afternoon of D1, which has been described as independent of the gonadotrophic action but was inhibited by neural effect of acetylcholine in our experimental scheme. This action on D1 was accompanied by a decrease of norepinephrine release in the ovary compartment. We conclude that the action of cholinergic agents varies according to the oestrous cycle stage and constitutes one of the factors governing the secretory activity of the ovarian steroids, in this case, progesterone.

Effect of the relation between neural cholinergic action and nitric oxide on ovarian steroidogenesis in prepubertal rats

The coeliac ganglion and the ovary are related by the superior ovarian nerve, which penetrates into the ovary by the hilium and innervates mainly the ovarian stroma. On the other hand, it is known that the gaseous neurotransmitter nitric oxide (NO) and the two isoforms of its synthesis enzyme, the nitric oxide synthetase (NOS), are present in the ovary. Both innervation and NO participate in ovarian steroidogenesis. Therefore, the purposes of this work were (a) to standardize an in vitro coeliac ganglion-superior ovarian nerve-ovary integrated system in prepubertal rats; (b) to determine the presence of NO in the ovary and analyze the ganglionic cholinergic effect on the ovarian release of androstenedione, progesterone and NO; and (c) to assess the steroids/NO relationship. The system was incubated in buffer solution for 120 min, with the ganglion and ovary located in different compartments and linked by the superior ovarian nerve. From the results obtained, it is concluded that the system is viable and functional. The presence of basal NO is stimulated by the cholinergic action, while the release of the steroids is inhibited, which might indicate that the ganglionic cholinergic effect is probably mediated by NO. To our knowledge, this work constitutes the first study of the relationship between the neural cholinergic action and NO on the ovarian steroidogenesis of prepubertal rats.

Neuroscience of Pavlovian conditioning: a brief review

Current knowledge on the neuronal substrates of Pavlovian conditioning in animals and man is briefly reviewed. First, work on conditioning in aplysia, that has showed amplified pre-synaptic facilitation as the basic mechanism of associative learning, is summarized. Then, two exemplars of associative learning in vertebrates, fear conditioning in rodents and eyelid conditioning in rabbits, are described and research into its neuronal substrates discussed. Research showing the role of the amygdala in fear conditioning and of the cerebellum in eyelid conditioning is reviewed, both at the circuit and cellular plasticity levels. Special attention is given to the parallelism suggested by this research between the neuronal mechanisms of conditioning and the principles of formal learning theory. Finally, recent evidence showing a similar role of the amygdala and of the cerebellum in human Pavlovian conditioning is discussed.

[Cognitive processes and emotional brain systems]

AIMS

In this review we analyse the role of learning and memory processes in normal and pathological emotional phenomena from an integrating perspective that combines the behavioural, cognitive and neurobiological levels. We examine the most recent trends in research into the emotional systems of the brain, which provide important keys to understanding the nature of emotional phenomena.

DEVELOPMENT

First, we discuss the existing evidence about the non conscious generation of affective responses, which come mainly from studies into Pavlovian fear conditioning. We then go on to analyse the relevance of the distinction between implicit and explicit memory in order to get a better understanding of the relations between cognition and emotion. The role played by the amygdala in the automatic evaluation of danger is considered a basic model for eliciting emotional responses. Finally, we describe how the interaction of the brain systems that the implicit and explicit aspects of emotional memory depend on provides an explanation for several characteristics of pathological anxiety, and we examine the positive or negative influences emotional activation can have on the consolidation of memory.

Tests for inhibition after extinction of a conditioned stimulus in the flavour aversion procedure

In four experiments, rats received flavour aversion conditioning followed by extinction. The flavour was then subjected to retardation and summation tests. Experiment 1 showed that reacquisition of an extinguished flavour aversion was retarded with respect to the performance shown by rats for whom the flavour was novel. No retardation was found, however, with respect to a control group that had been given non-reinforced pre-exposure to the flavour. Experiment 2 demonstrated that extinction showed the same sensitivity to the effects of a retention interval as did latent inhibition, consistent with the view that the retardation effect was a consequence of the occurrence of latent inhibition during extinction. An extinguished stimulus was also found to alleviate the response governed by a separately trained excitor in a summation test (Experiments 3 and 4), but the size of this effect did not exceed that produced by a control stimulus when the procedure used ensured an equivalent aversion to the test excitor in the two cases. These results challenge the proposal that extinction can turn a stimulus into a net inhibitor.

Secretion from neuropeptide-treated splenocytes modifies ovarian steroidogenesis

There are evidences for modulation of immune function by the sympathetic nervous system and its principal neurotransmitter norepinephrine (NE) through superior ovarian nerve (SON)-coeliac ganglion-noradrenergic postganglionic innervation of the spleen. Seven days after SON transection at 53 days of age, the rat splenocytes were isolated and then cultured for 48 h. These culture media, used to stimulate ovaries from 60-day-old intact rats (neither SON-transected nor sham-operated) at diestrus 2 stage, in in vitro incubations, showed a decrease in progesterone release, an increase in estradiol release and no change in androstenedione release in relation to splenocyte culture media from control (sham-operated) rats. When splenocytes from SON transected (SON-t) rats were treated with vasoactive intestinal peptide (VIP) or neuropeptide Y (NPY), both at 10(-6) M for 24 h, their secretions increased the progesterone release while decreasing the estradiol release from the intact ovaries, compared with the secretions of untreated splenocytes from SON-t rats. Although the secretions of splenocytes treated with VIP decrease the androstenedione release from the ovaries, the treatment with NPY produced no change in hormone release. In the present paper the ovarian steroidogenic response, which was modified by the effects of an in vivo SON transection on spleen cells, was reverted by an in vitro system in which the splenocytes were treated with VIP or NPY. This could indicate that the spleen of SON-t rats does not receive those neuropeptides by neural route however, when they are added to splenocyte culture in vitro, the cell secretions revert the profile of steroid hormones released from the intact ovary. We also present functional evidence for modulation of the immune function by sympathetic nervous system and neurotransmitters other than NE.

Adrenergic influences on coeliac ganglion affect the release of progesterone from cycling ovaries: characterisation of an in vitro system

The superior ovarian nerve (SON) arrives at the ovary through the suspensory ligament and innervates mainly the ovarian stroma. Most neurones from which the SON fibres originate are located in the complex coeliac and mesenteric ganglia. Taking into account that other ganglia have been shown to have alpha- and beta-adrenergic receptors, and that the coeliac ganglion receives adrenergic fibres from other sympathetic paravertebral and preaortic ganglia, we utilised adrenergic agonists and antagonists specific to the ganglion, to analyse the role of the alpha and beta receptors in ovarian physiology. To that end, it was necessary to develop and standardise an in vitro coeliac ganglion-SON-ovary (coeliac ganglion-SON-O) experimental system that would enable study of the release of steroids in the ovary in the absence of humoral factors. We investigated the effect of adrenergic agents on the liberation of progesterone in the different stages of the oestrous cycle. To this end we placed the coeliac ganglion and the ovary in different compartments, connected through the SON, to produce a system being studied as a whole. Combined neural and hormonal (luteinising hormone (LH)) effects were also examined. Non-specific stimulation with KCl in the ganglion compartment evoked different responses in terms of release of progesterone, depending on the physiological conditions of the cycle; this demonstrated the sensitivity and viability of the system. During pro-oestrus, stimulation of the ganglion compartment with adrenergic agents such as the agonist noradrenaline or the beta-adrenergic antagonist propranolol, did not modify the release of progesterone. In contrast, the alpha-adrenergic antagonist, phentolamine, induced a strong inhibitory response. During the oestrous stage, noradrenaline was inactive, but phentolamine and propranolol exerted a strong stimulus throughout the experiment. On dioestrus day 1 (D1), both noradrenaline and propranolol increased the release of ovarian progesterone, whereas phentolamine had the opposite effect. Finally, on dioestrus day 2 (D2), what was noteworthy was the pronounced inhibitory effect of noradrenaline, whereas phentolamine was inactive and propranolol showed its greatest stimulatory effect. In order to compare the combined neural and endocrine effects on the ovarian release of progesterone, the experiment was carried out during stages D1 and D2, when the corpora lutea are at their peak of activity. Adrenergic agents were added to the ganglion and LH in a final concentration of 50 ng/ml was added to the ovarian comparment. Different effects were observed indicating a differential response to these agents in stimulated and basal conditions. We conclude that the in vitro coeliac ganglion-SON-ovary system is a functional entity because it possesses its own autonomic tone. This is verified because different basal values of progesterone appear in the different stages of the oestrous cycle. In similar fashion, variations of progesterone induced via the neural pathway were observed under different experimental conditions. In contrast, on D2, noradrenaline added to the ganglion compartment had an inhibitory effect on the liberation of ovarian progesterone. This would indicate that, during this phase, noradrenaline may not be the neurotransmitter released in the ovarian compartment, but that other inhibitory molecules might participate in the observed effects. Finally, during D2, the neural input would condition the ovarian response to LH, facilitating the decrease in progesterone necessary to start a new cycle. The experimental scheme is, in our opinion, a valuable tool for the study of peripheral neural participation in ovarian physiology.

Effect of secretion of splenocytes after superior ovarian nerve section on the ovarian steroidogenesis

It is known that ovary and spleen are innervated extensively by afferent and efferent noradrenergic sympathetic nerve fibers from the celiac ganglion. Furthermore, immune cells located in the ovary influence the ovarian physiology. However, the peripheral interaction between the immune and neuroendocrine system is poorly understood. This work was undertaken to study the effect of superior ovarian nerve (SON) transection, in adult rats, on the number of splenocyte beta-adrenergic receptors and their possible relation to ovarian steroidogenesis, measuring the effect of secretions of those splenocytes on progesterone and estradiol release from the ovary. Seven days after SON transection, the splenocytes were isolated and then cultured for 48 h. Their number of beta-adrenergic receptors, measured using [125I]-cyanopindolol as ligand, increased, and their culture media, used to stimulate ovaries from 60-day-old intact (neither SON-transected nor sham-operated) rats in vitro on diestrous day 2 showed a decrease in progesterone release and an increase in estradiol release in relation to splenocyte culture media of control rats (sham-operated; p < 0.001, respectively). The effects of in vivo SON transection were simulated by an in vitro system modulating the splenocyte beta-adrenergic receptor number. The splenocytes from SON-transectioned rats were preincubated with and without norepinephrine (NE) 10(-6) M for 48 h, a low and high number of beta-adrenergic receptors respectively, and then were stimulated with NE 10(-6) M for 24 h. After that, the culture medium from splenocytes with a low number of beta-adrenergic receptors induced progesterone release from the ovaries of intact rats (p < 0. 001), but produced no change in estradiol release. The data suggest that splenocyte secretions, which participate in the ovarian steroidogenic response, particularly in progesterone release, might be controlled by adrenergic influences since the number of splenocyte beta-adrenergic receptors changes through SON-celiac ganglion-noradrenergic postganglionic innervation of the spleen. In estradiol release, probably other neurotransmitters than norepinephrine (NE) are involved when the SON is sectioned. In this paper we also show functional evidence for modulation of immune function by the sympathetic nervous system and its principal neurotransmitter, NE.

Illness-induced context aversion learning in rats with lesions of the dorsal hippocampus

In 2 experiments, rats with electrolytic lesions of the dorsal hippocampus and sham-operated control subjects were given injections of lithium chloride after exposure to a distinctive context. This procedure establishes a context-illness association in intact subjects. In Experiment 1, the strength of the context aversion was assessed by measuring the subjects' willingness to consume a novel flavor in the context. It was found that lesioned subjects showed less suppression of consumption than controls. Experiment 2 tested the ability of the context to block subsequent flavor-aversion learning and revealed less effective blocking in lesioned rats. These results are consistent with the view that hippocampal lesions retard context conditioning; unlike previous work that has made use of conditioned freezing as the measure of context conditioning, the present results are not explicable in terms of lesion-induced changes in general activity.

Illness-induced context aversion learning in rats with lesions of the dorsal hippocampus

In 2 experiments, rats with electrolytic lesions of the dorsal hippocampus and sham-operated control subjects were given injections of lithium chloride after exposure to a distinctive context. This procedure establishes a context-illness association in intact subjects. In Experiment 1, the strength of the context aversion was assessed by measuring the subjects' willingness to consume a novel flavor in the context. It was found that lesioned subjects showed less suppression of consumption than controls. Experiment 2 tested the ability of the context to block subsequent flavor-aversion learning and revealed less effective blocking in lesioned rats. These results are consistent with the view that hippocampal lesions retard context conditioning; unlike previous work that has made use of conditioned freezing as the measure of context conditioning, the present results are not explicable in terms of lesion-induced changes in general activity.

[Effect of adenohypophyseal pars tuberalis secretions on pars distalis prolactin liberation]

Evidences presented indicating that factors produced by the pars tuberalis (PT) affect the prolactin liberation by the pars distalis (PD). The effect of the secretion products of bovine PT cells in culture medium was checked on dispersed PD cells of rats. PD cells were assayed in incubations of 30 minutes and superfusion experiments. When medium was obtained from total PT cells, the addition of 9 micrograms of protein was needed to reach the major stimulation of prolactin liberation. However, when the medium from 50-60% Percoll gradient fractions was used, only 4 micrograms of total protein were required. The partial purification of such medium by Sephadex G50 produced the same effect on the liberation of prolactin by PD cells with 80 ng of total protein. The active factor/s should have a molecular weight higher than 30 kDal. The results obtained suggest, at least for the prolactotrophic cells, that PD could be the effector organ for some of the secretory product(s) of PT.

The NMDA-receptor antagonist ketamine as an unconditioned stimulus in taste aversion learning

Three experiments studied the effectiveness of ketamine acting as an aversive unconditioned stimulus (UCS) in a conditioned flavor aversion procedure. In Experiment 1a, three conditioning trials where sucrose was paired with ketamine produced a weak but significant aversion to sucrose; Experiment 1b showed that this effect was not due to a reduced consumption of sucrose caused by ketamine-induced neophobia. In Experiment 2, acquisition of an aversion to sucrose paired with lithium chloride (LiCl) injections was retarded by prior repeated exposure to LiCl but not to ketamine. These results are not consistent with an interpretation of previous results, showing that ketamine impairs the acquisition of flavor aversions based on LiCl-induced illness, as an example of the UCS preexposure effect.

Effects of the NMDA receptor antagonist ketamine on flavor memory: conditioned aversion, latent inhibition, and habituation of neophobia

In four experiments with rats, the effects of the NMDA antagonist ketamine on several forms of gustatory learning were studied. Replicating previous findings, in Experiment 1 ketamine was shown to impair one-trial acquisition of a flavor aversion at the dose of 25 mg/kg, but also produced a significant state-dependency effect. In Experiment 2 ketamine did not alter the process of habituation of neophobia to a new flavor. Abolition of latent inhibition by ketamine injected before preexposure in Experiment 3a was not replicated in Experiment 3b when ketamine was injected before all phases of the experiment. Finally, in Experiment 4 rats injected with ketamine showed slower acquisition of a flavor aversion with a multiple-trial procedure but finally reached a level similar to that shown by saline controls. The implications of these results for an interpretation of the effects of ketamine on flavor aversion learning in terms of interference with flavor memory storage are discussed.

Angiotensin II and glucocorticoid release: direct effect at the adrenal level and modulation of the adrenocorticotropin-induced glucocorticoid release

Angiotensin II (A II) stimulates adrenal glomerulosa cells releasing mineralocorticoids; however, little is known about the A II effect on glucocorticoids output. The present study has been designed in order to see if A II could modify in vitro spontaneous and ACTH-induced corticosterone (B) release from both fasciculata-reticularis enriched and total adrenal cells. The results indicate that A II at 10(-12), 10(-11), 10(-10) and 10(-6) M concentrations did not modify basal B production and A II 10(-9), 10(-8) and 10(-7) M decreased basal B production from total adrenal cells. Whereas A II (10(-10)-10(-6) M) stimulated B release from fasciculata-reticularis enriched cells. On the one hand, 10(-8) M A II significantly decreased ACTH-elicited B release from total adrenal cells; effect completely abolished by saralasin (SAR, 10(-8) M), a specific A II receptor blocker. On the other hand, 10(-8) M A II did not modify ACTH-induced B release from fasciculata-reticularis enriched cells. Finally, 10(-10) to 10(-6) M A II and 22 pM ACTH stimulated aldosterone output from total adrenal cells; while, fasciculata-reticularis enriched cells did not secrete any measurable amount of aldosterone under basal condition and after incubation with A II. These data further suggest a regulatory role of A II in the release of glucocorticoids from the adrenal gland.