Specialist-based treatment reduces the severity of allergic rhinitis

BACKGROUND

Although the treatment of allergic rhinitis (AR) is now well established, its impact on severity has not yet been evaluated.

OBJECTIVE

The aim was to analyse specialist-based treatment on AR severity, nasal symptoms and quality of life.

METHODS

A longitudinal observational, prospective, multi-centre study with 4 weeks of follow-up was carried out by 141 allergologists and ENT specialists in Spain. Selection criteria were adult patients with AR, clinically diagnosed at least 2 years before, with a total nasal symptom score (TNSS) ≥5, not receiving either antihistamines within the previous week or nasal corticosteroids during the 2 previous weeks. Disease severity using both original Allergic Rhinitis and its Impact on Asthma (o-ARIA) and modified (m-ARIA) classifications, nasal symptoms, and Quality of Life (ESPRINT-15), were measured at baseline and after 4 weeks of treatment.

RESULTS

Among the recruited AR patients (n = 707, 58% women), 39.3% were intermittent and 60.7% persistent, 40.2% had asthma and 61.4% conjunctivitis. Most patients were treated with second generation antihistamines in monotherapy (63.2%) or in combination with intranasal corticosteroids (31.5%). While using o-ARIA, 96.9% of patients had 'moderate/severe' AR, the m-ARIA discriminated between 'moderate' (55.4%) and severe (41.5%) AR, at baseline. After 4 weeks of treatment, improvement was found on disease severity (P < 0.0001), TNSS (8.2 ± 1.8 vs. 3.5 ± 2.3, P < 0.0001) and Quality of Life (ESPRINT-15 global score: 3.0 ± 1.2 vs. 1.1 ± 1.0, P < 0.0001).

CONCLUSIONS

Specialist-based treatment reduces AR severity, evaluated using the m-ARIA classification for the first time, in addition to the improvement of nasal symptoms and quality of life.

CLINICAL RELEVANCE

Specialist-based treatment improves AR severity, in addition to nasal symptoms and quality of life. However, no matter the treatment option some AR patients remain severe and need further follow-up.

A direct comparison of efficacy between desloratadine and rupatadine in seasonal allergic rhinoconjunctivitis: a randomized, double-blind, placebo-controlled study

Background

H1-antihistamines are recommended as the first-line symptomatic treatment of allergic rhinitis. The objective of this study was to evaluate the effects of rupatadine (RUP) versus desloratadine (DES) in subjects with seasonal allergic rhinitis (SAR).

Method

To assess the efficacy and safety of RUP in SAR in comparison with placebo (PL) and DES. A randomized, double-blind, multicenter, international, and PL-controlled study was carried out. The main selection criteria included SAR patients over 12 years old with a positive prick test to a relevant seasonal allergen for the geographic area. Symptomatic patients at screening with a nasal symptom sum score of ≥6 points (nasal discharge, nasal obstruction, sneezing, and nasal pruritus), a non-nasal score of ≥3 points (ocular pruritus, ocular redness, and tearing eyes), and a rhinorrhea score of ≥2 points with laboratory test results and electrocardiography within acceptable limits were included in the study. Change from baseline in the total symptom-score (T7SS) over the 4-week treatment period (reflective evaluation) was considered the primary efficacy variable. Secondary efficacy measures included total nasal symptom score (T4NSS) and conjunctival symptom score (T3NNSS), both of which are reflective and instantaneous evaluations. Furthermore questions related to quality of life (eg, sleep disturbances or impairment of daily activities) have also been evaluated. Safety was assessed according to adverse events reported, as well as laboratory and electrocardiography controls.

Results

A total of 379 patients were randomized, of which 356 were included and allocated to PL (n = 122), RUP (n = 117), or DES (n = 117). Mean change of T7SS over the 4-week treatment period was significantly reduced in the RUP (–46.1%, P = 0.03) and DES (–48.9%, P = 0.01) groups, compared with PL. Similarly, RUP and DES were comparable and significantly superior to PL for all secondary endpoints, including nasal and conjunctival symptoms and patients’ and investigator’s overall clinical opinions. Symptom score evaluation (both reflective and instantaneous evaluations) throughout the treatment period showed a progressive and maintained significant improvement with both treatments at day 7 (P = 0.01), day 14 (P = 0.007), and day 21 (P = 0.01) in comparison with PL. Adverse events were scarce and were similar in both treatment groups. Electrocardiography (QTc) and lab test results did not show any relevant findings

Conclusion

RUP is a very good choice for SAR due to its contribution to the improvement of nasal (including obstruction) and non-nasal symptoms to a similar degree as DES.

ESPRINT-15 questionnaire (Spanish version): reference values according to disease severity using both the original and the modified ARIA classifications

OBJECTIVE

ESPRINT-15 is a specific and validated instrument to measure health-related quality of life in adults with allergic rhinitis. The aim of this study was to obtain new reference values based on disease severity using both the original and the modified versions of the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines.

METHODS

ESPRINT-15 was administered to a representative sample of adults with allergic rhinitis in Spain. As in a previous study by our group, means and percentiles were analyzed for 16 quotas based on gender, allergic rhinitis type (intermittent vs persistent), and 4 symptom intensity groups according to the total symptom score (TSS4). The novel aspect of the present study was our application the severity criteria proposed by both the original and the modified ARIA classifications.

RESULTS

Of the 2756 patients in our previous dataset, 2580 were included in the present analysis. In terms of symptom severity, women ha relatively more intense symptoms than men with both ARIA classifications. In fact, using only the modified ARIA classification, we were abl to determine that severe rhinitis is moderately more frequent in women (27% vs 23%), although the difference is not statistically significant.

CONCLUSIONS

The new set of reference values enables the ESPRINT-15 questionnaire to be adapted to the current severity classification Consequently, this quality of life tool (http://www.seaic.org/inicio/esprint) can be easily used and better interpreted in daily clinical practice.

Rupatadine improves nasal symptoms, quality of life (ESPRINT-15) and severity in a subanalysis of a cohort of Spanish allergic rhinitis patients

BACKGROUND

According to current guidelines, new second-generation oral Hi-antihistamines, as well as intranasal corticosteroids (ICSs), are recommended for the treatment of allergic rhinitis (AR) in adults and children.

OBJECTIVE

To assess changes in AR severity, in addition to nasal symptoms and health-related quality of life (HRQoL), after 4 weeks of treatment with rupatadine in a cohort of AR patients.

METHODS

A subanalysis of a longitudinal, observational, prospective, multicenter Spanish study was carried out in spring-summer 2007. Enrolled patients had a clinical diagnosis of AR of at least 2 years' evolution, a total nasal symptom score (TNSS) of at least 5, and had not received antihistamines in the previous week or ICSs in the previous 2 weeks. HRQoL (ESPRINT-15 questionnaire), disease severity (using both the original and modified Allergic Rhinitis and its Impact on Asthma [ARIA] classifications), and nasal symptoms (TNSS) were measured at baseline and after 4 weeks of rupatadine treatment.

RESULTS

Data from a cohort of 360 patients treated with rupatadine were analyzed (57.2% women, 42.5% with intermittent AR, 36.4% with asthma, and 61.7% with conjunctivitis). After 4 weeks of treatment, the patients showed a significantly lower mean (SD) TNSS (8.2 [1.9] vs 3.1 [2.1], P < .001), a significant improvement in HRQoL (3.0 [1.2] vs 1.0 [0.9], P < .001) and significantly reduced AR severity (P < .0001).

CONCLUSIONS

In addition to an improvement in nasal symptoms and HRQoL, rupatadine reduced AR severity after 4 weeks of treatment.

Discrimination between moderate and severe disease may be used in patients with either treated or untreated allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common disease with major socioeconomic burden and a significant impact on quality of life.

OBJECTIVE

  The aim of this study was to discriminate between moderate and severe AR patients whether receiving treatment or not, using a modified criterion of allergic rhinitis and its impact on asthma (ARIA) classification.

METHODS

The modified ARIA severity classification (J Allergy Clin Immunol, 120, 2007, 359) categorizes AR as mild (no items affected), moderate (1-3 items affected), and severe (all four items affected). We applied these criteria to 1666 treated and 1058 untreated AR patients and compared their symptoms total four-symptom score (T4SS) and quality of life (ESPRINT-15), according to their clinical severity.

RESULTS

Allergic rhinitis clinical status was significantly worse (P < 0.001) in treated than in untreated patients. For both treated and untreated patients, T4SS and ESPRINT-15 Quality of life scores were significantly worse (P < 0.001) in severe than in moderate patients.

CONCLUSIONS

The modified ARIA severity classification is a useful clinical tool to discriminate moderate from severe AR among both treated and untreated patients.

The use of a responder analysis to identify clinically meaningful differences in chronic urticaria patients following placebo- controlled treatment with rupatadine 10 and 20 mg

BACKGROUND

According to the EAACI/GA(2)LEN/EDF guidelines for urticaria management, modern non-sedating H1-antihistamines are the first-line symptomatic treatment for chronic urticaria. Two previous randomized clinical trials demonstrated rupatadine efficacy and safety in chronic urticaria treatment. However, a responder analysis to identify clinically meaningful differences in patients with chronic urticaria has not yet been performed.

METHODS

This analysis includes the pooled data from two randomized, double-blind, placebo-controlled, multicentre studies in which chronic urticaria patients were treated with rupatadine at different doses. Responder rates were defined as the percentage of patients after 4 weeks of treatment who exhibited a reduction of symptoms by at least 50% or 75% as compared to baseline. The variables analysed were as follows: Mean Pruritus Score (MPS), Mean Number of Wheals (MNW), and Mean Urticaria Activity Score (UAS).

RESULTS

A total of 538 patients were included. This responder analysis, using different response levels, shows that the efficacy of rupatadine 10 mg and 20 mg is significantly better as compared to placebo in the treatment of chronic urticaria patients. Notably, treatment with rupatadine 20 mg daily resulted in a higher percentage of patients with response of 75% symptom reduction or better than rupatadine 10 mg.

CONCLUSION

Our results support the use of higher than standard doses of non sedating antihistamines in chronic urticaria. We strongly recommend performing and reporting responder analyses for established and new drugs used by patients with chronic urticaria.

Validation of the COPD severity score for use in primary care: the NEREA study

Spirometry is underused for the assessment of severity of chronic obstructive pulmonary disease (COPD) in primary care (PC). Therefore, simple assessment tools are required in this setting. The aim of the present study was to validate the COPD severity score (COPDSS) for use in PC. A multicentric study was carried out in stable COPD patients in PC. The concurrent validity of the COPDSS was evaluated by examining the association between COPDSS, COPD clinical indicators and the London Chest Activity of Daily Living (LCADL) scale, European quality of life (EuroQOL) questionnaires and Charlson comorbidity index. A total of 837 patients with COPD were analysed (males 84.3%; mean+/-sd age 68+/-11 yrs; forced expiratory volume in one second 54.6+/-17.7% of the predicted value). A strong correlation was found between COPDSS and dyspnoea level and a moderate correlation between COPDSS and exacerbation number. The COPDSS discriminated between patients with varying degrees of dyspnoea (area under receiver operating characteristic (ROC) curve 0.837), and according to number of exacerbations in the last year (area under ROC curve 0.773). Higher COPDSS scores were significantly associated with lower EuroQOL scores, lower EuroQOL visual analogue scale scores and higher LCADL scores. The present results indicate that the chronic obstructive pulmonary disease severity score is a useful and reliable tool for assessing the severity of chronic obstructive pulmonary disease in primary care.

Reduction of nasal volume after allergen-induced rhinitis in patients treated with rupatadine: a randomized, cross-over, double-blind, placebo-controlled study

OBJECTIVE

To measure the reduction in nasal obstruction using acoustic rhinometry in patients with allergic rhinitis treated with rupatadine.

METHODS

We performed a randomized, double-blind, cross-over, placebo-controlled clinical trial in asymptomatic patients with allergic rhinitis. Patients received rupatadine 10 mg or placebo once daily for 3 days, in 2 subsequent periods separated by a washout interval of 14 days. We performed a nasal allergen challenge during each period, and measured nasal volume using acoustic rhinometry and nasal nitric oxide (nNO) at baseline, and at 2 hours and 24 hours after the challenge. We also evaluated nasal symptoms (rhinorrhea, itching, obstruction, and sneezing), as well as total symptom score (T4SS) at the same time points as for the primary objective.

RESULTS

The study population comprised 30 outpatients with a mean (SD) age of 28 (10) years. Nasal airway blockage was significantly lower in the rupatadine group than in the placebo group (47%, P < .05) at 2 hours postchallenge. nNO in the rupatadine-treated patients remained unaltered, unlike in the placebo-treated group, where levels decreased at 2 hours. After treatment with rupatadine, patients showed a lower decrease in the mean total symptoms score at 2 hours (3.6 [2.6]) compared with placebo (3.9 [2.9]), although these differences did not achieve statistical significance. Overall, rupatadine was well tolerated and no serious or unexpected adverse events were observed.

CONCLUSIONS

Rupatadine 10 mg can reduce nasal obstruction assessed by objective measures and is well tolerated in patients with allergic rhinitis.

Reference values for facilitating the interpretation of the ESPRINT-15 questionnaire (Spanish version)

OBJECTIVE

ESPRINT-15 is a specific, short-form instrument to measure health-related quality of life in adults suffering from allergic rhinitis. The aim of this study was to obtain reference values in order to improve its interpretability.

METHODS

ESPRINT-15 was administered to a representative sample of Spanish adults with allergic rhinitis. Means and percentiles were obtained, taking into account the kind of rhinitis (persistent/intermittent) and symptom severity (very mild/mild/moderate/severe).

RESULTS

A total of 2756 patients participated in the study. Mean (SD) scores were significantly lower (better) for men than for women (2.2 [1.4] vs 2.4 [1.4], P<.001, effect size [ES] is congruent to 0.15). Patients with intermittent rhinitis showed better scores than patients with persistent rhinitis (2.1 [1.4] vs. 2.5 [1.4], P<.001, ES is congruent to 0.21). Mean (SD) scores were higher (worse) when severity of symptoms increased, ranging from 0.9 (0.9) (very mild) to 3.7 (1.0) (severe) (ES is congruent to 1.0 between each consecutive group of symptom severity).

CONCLUSIONS

The magnitude of the differences found among groups of patients reinforces the usefulness of providing reference values stratified by gender, type of allergic rhinitis, and symptom severity. The percentiles obtained can be used in clinical practice to evaluate individual scores, and assign the patient to the corresponding reference group.

Neonatal handling and the maternal odor preference in rat pups: involvement of monoamines and cyclic AMP response element-binding protein pathway in the olfactory bulb

Early-life environmental events, such as the handling procedure, can induce long-lasting alterations upon several behavioral and neuroendocrine systems. However, the changes within the pups that could be causally related to the effects in adulthood are still poorly understood. In the present study, we analyzed the effects of neonatal handling on behavioral (maternal odor preference) and biochemical (cyclic AMP response element-binding protein (CREB) phosphorylation, noradrenaline (NA), and serotonin (5-HT) levels in the olfactory bulb (OB)) parameters in 7-day-old male and female rat pups. Repeated handling (RH) abolished preference for the maternal odor in female pups compared with nonhandled (NH) and the single-handled (SH) ones, while in RH males the preference was not different than NH and SH groups. In both male and female pups, RH decreased NA activity in the OB, but 5-HT activity increased only in males. Since preference for the maternal odor involves the synergic action of NA and 5-HT in the OB, the maintenance of the behavior in RH males could be related to the increased 5-HT activity, in spite of reduction in the NA activity in the OB. RH did not alter CREB phosphorylation in the OB of both male and females compared with NH pups. The repeated handling procedure can affect the behavior of rat pups in response to the maternal odor and biochemical parameters related to the olfactory learning mechanism. Sex differences were already detected in 7-day-old pups. Although the responsiveness of the hypothalamic-pituitary-adrenal axis to stressors is reduced in the neonatal period, environmental interventions may impact behavioral and biochemical mechanisms relevant to the animal at that early age.

Reduced expression of the vesicular acetylcholine transporter causes learning deficits in mice

Storage of acetylcholine in synaptic vesicles plays a key role in maintaining cholinergic function. Here we used mice with a targeted mutation in the vesicular acetylcholine transporter (VAChT) gene that reduces transporter expression by 40% to investigate cognitive processing under conditions of VAChT deficiency. Motor skill learning in the rotarod revealed that VAChT mutant mice were slower to learn this task, but once they reached maximum performance they were indistinguishable from wild-type mice. Interestingly, motor skill performance maintenance after 10 days was unaffected in these mutant mice. We also tested whether reduced VAChT levels affected learning in an object recognition memory task. We found that VAChT mutant mice presented a deficit in memory encoding necessary for the temporal order version of the object recognition memory, but showed no alteration in spatial working memory, or spatial memory in general when tested in the Morris water maze test. The memory deficit in object recognition memory observed in VAChT mutant mice could be reversed by cholinesterase inhibitors, suggesting that learning deficits caused by reduced VAChT expression can be ameliorated by restoring ACh levels in the synapse. These data indicate an important role for cholinergic tone in motor learning and object recognition memory.

A 12-week placebo-controlled study of rupatadine 10 mg once daily compared with cetirizine 10 mg once daily, in the treatment of persistent allergic rhinitis

BACKGROUND

With the current increasing incidence of allergies worldwide, new treatments showing efficacy and long term safety are needed for chronic conditions such as persistent allergic rhinitis (PER). New generation H1-antihistamines have demonstrated anti-allergic properties, which could possibly enhance their effectiveness in long-term periods of treatment.

OBJECTIVE

To investigate the efficacy of rupatadine, in controlling symptoms of PER over a 12-week period.

METHODS

A randomized, double blind, parallel-group, placebo-controlled study was carried out in patients aged older than 12 years with PER. Main inclusion criteria were: instantaneous total symptom score (i6TSS) >or=45, nasal obstruction score <or=12, and overall assessment of PER >or=2 as moderate during the first visit. The primary efficacy endpoint was the 12-week average change from baseline of the patients' i6TSS.

RESULTS

In all, 736 patients were selected. Of them, 543 (73.8%) were randomized in three different groups: placebo (n = 185), cetirizine (n = 175) and rupatadine (n = 183). Rupatadine (P = 0.008) but not cetirizine (P = 0.07) statistically reduced the baseline i6TSS vs placebo (47.8%, 44.7% and 38.8%, respectively), after 12 weeks. Onset of action was observed at the first 24 h for both treatments (rupatadine vs placebo, P = 0.013; cetirizine vs placebo, P = 0.015). Furthermore, instantaneous total nasal symptoms score (iTNSS) (including nasal blockage) mean change from baseline showed a significant reduction with rupatadine 10 mg in comparison with placebo, along all treatment duration of 12 weeks. Study treatments were well tolerated.

CONCLUSION

Rupatadine significantly relieves symptoms of PER, providing a rapid onset of action and maintains its effects over a long period of 12-weeks.

Safety of triflusal (antiplatelet drug) in patients with aspirin-exacerbated respiratory diseases

BACKGROUND AND AIMS

Aspirin, a cyclo-oxygenase (COX)-1 and COX-2 inhibitor, is the antiplatelet drug of choice to prevent serious vascular events. Adverse reactions to aspirin are frequent particularly among patients with asthma, chronic rhinosinusitis and nasal polyps. COX-1 inhibitors but not COX-2 inhibitors precipitate asthma attacks. Triflusal is a preferential COX-2 inhibitor antiplatelet agent that is as effective as aspirin in the prevention of serious vascular events. The aim of the study was to assess the tolerability of triflusal in patients with aspirin-exacerbated respiratory disease (AERD).

METHODS

We studied 26 asthma patients [11 males, aged 52 (23-75) years] who had suffered asthma episodes triggered by one or more (23% of patients) nonsteroidal anti-inflammatory drugs. Aspirin sensitivity was confirmed by either intranasal or oral aspirin challenge. All subjects underwent a single-blind, placebo-controlled oral challenge with three doses of triflusal separated by 1 week (first cumulative dose = 225 mg; second cumulative dose = 450 mg; third cumulative dose = 900 mg). Cutaneous, respiratory, general symptoms and lung function were monitored for 4 h in the laboratory and for 24 h at home.

RESULTS

No clinical reactions to triflusal were observed. There were no significant changes in lung function measurements.

CONCLUSION

Our study appears to demonstrate that triflusal is a suitable alternative to aspirin as antiplatelet agent to prevent AERD.

Health-related quality of life in allergic rhinitis: comparing the short form ESPRINT-15 and MiniRQLQ questionnaires

BACKGROUND

We compared the psychometric properties of the ESPRINT-15, the short form of a new Spanish instrument to measure health-related quality of life in allergic rhinitis (AR) patients, with those of the Mini-Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ).

METHODS

The questionnaires were compared in Spanish patients with intermittent allergic rhinitis (IAR) or persistent AR in a prospective, observational study. Floor and ceiling effects, internal consistency (Cronbach's alpha), test-retest reliability (intraclass correlation coefficient; ICC), convergent and known groups validity, and sensitivity to change (standardized response means; SRMs) were compared.

RESULTS

In terms of content, while the MiniRQLQ has a dimension covering practical problems and places more emphasis on symptoms, the ESPRINT-15 has two dimensions (Sleep and Psychological impact) which are not included in the MiniRQLQ. In the validation study, 400 patients were included and 59% of the sample had persistent AR. There were no significant floor or ceiling effects on any dimension on either questionnaire. Cronbach's alpha values for the ESPRINT-15 and MiniRQLQ overall scores were 0.92 and 0.90, respectively. In 48 clinically stable patients, ICCs were 0.80 and 0.77, respectively. Both instruments discriminated between patients with IAR and persistent AR. Correlations with symptom scores and generic measures were moderate to strong. SRMs for overall scores and individual dimensions on the two questionnaires in the 197 patients reporting a change in health status ranged from 0.7 to 1.3.

CONCLUSIONS

Both questionnaires performed well in psychometric terms. The ESPRINT-15 is particularly recommended for use in Spanish-speaking populations.

On the participation of hippocampal PKC in acquisition, consolidation and reconsolidation of spatial memory

Memory consolidation involves a sequence of temporally defined and highly regulated changes in the activation state of several signaling pathways that leads to the lasting storage of an initially labile trace. Despite appearances, consolidation does not make memories permanent. It is now known that upon retrieval well-consolidated memories can become again vulnerable to the action of amnesic agents and in order to persist must undergo a protein synthesis-dependent process named reconsolidation. Experiments with genetically modified animals suggest that some PKC isoforms are important for spatial memory and earlier studies indicate that several PKC substrates are activated following spatial learning. Nevertheless, none of the reports published so far analyzed pharmacologically the role played by PKC during spatial memory processing. Using the conventional PKC and PKCmu inhibitor 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrollo[3,4-c]carbazole (Gö6976) we found that the activity of these kinases is required in the CA1 region of the rat dorsal hippocampus for acquisition and consolidation of spatial memory in the Morris water maze learning task. Our results also show that when infused into dorsal CA1 after non-reinforced retrieval, Gö6976 produces a long-lasting amnesia that is independent of the strength of the memory trace, suggesting that post-retrieval activation of hippocampal PKC is essential for persistence of spatial memory.

Rupatadine in the treatment of chronic idiopathic urticaria: a double-blind, randomized, placebo-controlled multicentre study

BACKGROUND

Chronic urticaria is one of the most common and disturbing cutaneous condition. The treatment of chronic idiopathic urticaria (CIU) is still a challenge. Antihistamines are recommended as first-line treatment. Rupatadine is a new potent nonsedative anti-H1.

OBJECTIVE

To study rupatadine efficacy and safety for moderate to severe CIU treatment.

METHODS

This randomized, double-blind, placebo-controlled, parallel-group, multicentre, study was designed to assess primarily mean pruritus score (MPS) reduction with rupatadine, 10 and 20 mg, administered once daily for 4 weeks. Three hundred and thirty-three patients with active episodes of moderate-to-severe CIU were included.

RESULTS

A 57.5% (P < 0.005) and 63.3% (P = 0.0001) significative MPS reduction from baseline, was observed at week 4 with 10 and 20 mg rupatadine, respectively, compared with placebo (44.9%). Both doses of rupatadine were not significantly different at any time point, with respect to their effects on pruritus severity, number of wheals and total symptoms scores. Rupatadine 10 mg had an overall better adverse event profile.

CONCLUSION

Rupatadine 10 mg is a fast, long-acting, efficacious and safe treatment option for the management of patients with moderate-to-severe CIU.

The benefits and drawbacks of nicotine exposure in the cortex and hippocampus of old rats

Nicotine is the main alkaloid of tobacco and possesses well-established stimulant effects. Previous reports show that nicotine at low doses improves memory functions, while high doses impair memory. This study aims to analyze the effects of nicotine (NIC) on inhibitory avoidance task and on DNA damage, reactive oxygen species (ROS) concentration, total antioxidant capacity, and lipid peroxidation in cortex and hippocampus of old rats. Male Wistar rats of 24-26 months old (620-700g) were exposed i.p. to two doses (0.3 and 1mg/kg) of NIC daily during 9 days. The treatment NIC 0.3 enhanced long-term memory (p<0.05), whereas NIC 1 improved both short and long-term memories (p<0.05). DNA damage was observed only in hippocampus (p<0.05) after NIC 1 exposure. A similar result was obtained for ROS: higher levels were detected at NIC 1 treatment in hippocampus (p<0.05). No alterations in the total antioxidant capacity were verified after NIC exposure (0.3 and 1mg/kg) in both tissues (p>0.05). Finally, evidence of oxidative damage was observed in terms of lipid peroxides levels, being higher at NIC 1 in hippocampus (p<0.05). Overall the results indicate that deleterious effects paralleled the improved short and long-term memories at the highest NIC dose, since augmented DNA damage, ROS concentration and lipid peroxides levels were registered.

On the participation of hippocampal p38 mitogen-activated protein kinase in extinction and reacquisition of inhibitory avoidance memory

Inhibitory avoidance (IA) learning relies on the formation of an association between stepping down from a platform present in a certain context (conditioned stimulus; CS) with an aversive unconditioned stimulus (US; i.e. a footshock). A single CS-US pairing establishes a robust long-term memory expressed as an increase in step-down latency at testing. However, repeated retrieval of the avoidance response in the absence of the US induces extinction of IA memory. That is, recurring presentation of the CS alone results in a new learning indicating that the CS no longer predicts the US. Although the signaling pathways involved in the consolidation of IA and other fear-motivated memories have been profusely studied, little is known about the molecular requirements of fear memory extinction. Here we report that, as happens with its consolidation, extinction of IA long-term memory requires activity of the p38 subfamily of mitogen-activated protein kinases (MAPK) in the CA1 region of the dorsal hippocampus. Moreover, we found that inhibition of hippocampal p38MAPK blocked memory reacquisition after extinction without affecting either the increase in IA memory retention induced by a second training session or animal's locomotor/exploratory activity and anxiety state.

Molecular mechanisms mediating gastrin-releasing peptide receptor modulation of memory consolidation in the hippocampus

Although the gastrin-releasing peptide-preferring bombesin receptor (GRPR) has been implicated in memory formation, the underlying molecular events are poorly understood. In the present study, we examined interactions between the GRPR and cellular signaling pathways in influencing memory consolidation in the hippocampus. Male Wistar rats received bilateral infusions of bombesin (BB) into the dorsal hippocampus immediately after inhibitory avoidance (IA) training. Intermediate doses of BB enhanced, whereas a higher dose impaired, 24-h IA memory retention. The BB-induced memory enhancement was prevented by pretraining infusions of a GRPR antagonist or inhibitors of protein kinase C (PKC), mitogen-activated protein kinase (MAPK) kinase and protein kinase A (PKA), but not by a neuromedin B receptor (NMBR) antagonist. We next further investigated the interactions between the GRPR and the PKA pathway. BB-induced enhancement of consolidation was potentiated by coinfusion of activators of the dopamine D1/D5 receptor (D1R)/cAMP/PKA pathway and prevented by a PKA inhibitor. We conclude that memory modulation by hippocampal GRPRs is mediated by the PKC, MAPK, and PKA pathways. Furthermore, pretraining infusion of BB prevented beta-amyloid peptide (25-35)-induced memory impairment, supporting the view that the GRPR is a target for the development of cognitive enhancers for dementia.

The connection between the hippocampal and the striatal memory systems of the brain: A review of recent findings

Two major memory systems have been recognized over the years (Squire, in Memory and Brain, 1987): the declarative memory system, which is under the control of the hippocampus and related temporal lobe structures, and the procedural or habit memory system, which is under the control of the striatum and its connections (Mishkin et al., in Neurobiology of Learning by G Lynch et al., 1984; Knowlton et al., Science 273:1399, 1996). Most if not all learning tasks studied in animals, however, involve either the performance or the suppression of movement. Animals acquire connections between environmental or discrete sensory cues (conditioned stimuli, CSs) and emotionally or otherwise significant stimuli (unconditioned stimuli, USs). As a result, they learn to perform or to inhibit the performance of certain motor responses to the CS which, when learned well, become what can only be called habits (Mishkin et al., 1984): to regularly walk or swim to a place or away from a place, or to inhibit one or several forms of movement. These responses can be viewed as conditioned responses (CRs) and may sometimes be very complex. This is of course also seen in humans: people learn how to play on a keyboard in response to a mental or written script and perform the piano or write a text; with practice, the performance improves and eventually reaches a high criterion and becomes a habit, performed almost if not completely without awareness. Commuting to school in a big city in the shortest possible time and eschewing the dangers is a complex learning that children acquire to the point of near-perfection. It is agreed that the rules that connect the perception of the CS and the expression of the CR change from their first association to those that take place when the task is mastered. Does this change of rules involve a switch from one memory system to another? Are different brain systems used the first time one plays a sonata or goes to school as compared with the 100th time? Here we will comment on: 1) reversal learning in the Morris water maze (MWM), in which the declarative or spatial component of a task is changed but the procedural component (to swim) persists and needs to be re-linked with a different set of spatial cues; and 2) a series of observations on an inhibitory avoidance task that indicate that the brain systems involved change with further learning.

[Recommendations for the prevention of respiratory syncytial virus infection]

Premature babies < or = 35 weeks gestation, with or without chronic lung disease (CLD), and infants affected by severe congenital heart disease should be considered high risk population for RSV infection and hospitalization. Hygienic measures and RSV monoclonal antibodies (palivizumab) have been found useful in decreasing rates of RSV hospitalization in these patients. Guidelines for their administration include: a) strongly recommended use in premature babies < or = 28 weeks gestation, or born between 29-32 weeks gestation and less than 6 months at start of RSV station or discharged along it, or affected by CLD in treatment during last 6 months or by severe congenital heart disease. Last two groups could be prophylaxed for two RSV seasons. b) Recommended use among premature babies between 32-35 weeks gestation and less than 6 months of age and presenting two or more risk factors: chronologic age < 10 weeks at start of RSV station, breastfeeding < or = 2 months (physician prescription), sibling < 14 years old, day-care assistance, family history of wheezing, > or = 4 adults at home, airways malformation or neuromuscular disease.

Access of HTB, main metabolite of triflusal, to cerebrospinal fluid in healthy volunteers

OBJECTIVE

Triflusal has been shown to exert neuroprotective effects by downregulating molecules considered responsible for the development of Alzheimer's disease (AD). The aim of this study was to develop a population pharmacokinetic model to characterize plasma and cerebrospinal fluid (CSF) pharmacokinetics of the main active metabolite of triflusal-HTB (2-hydroxy-4-trifluoro-methylbenzoic acid)-in healthy volunteers.

METHODS

Data from two studies were combined. Study A: subjects received single oral doses of triflusal 900 mg. Triflusal and HTB plasma concentrations were extensively measured. Study B: triflusal 600 mg once daily was administered orally for 14 days. HTB plasma and CSF concentrations were determined in healthy volunteers. Population pharmacokinetic modeling was performed using NONMEM.

RESULTS

A one-compartmental model with rapid first-order absorption for triflusal and first-order formation of HTB best described plasma concentrations. Triflusal elimination rate constant was 50 times faster than that estimated for the metabolite. CSF concentrations of HTB ranged between 0.011 microg/ml and 0.341 microg/ml. A CSF-plasma partition coefficient of 0.002 and a k(e0) value of 0.059 h(-1) were estimated by means of population modeling.

CONCLUSION

In the present study in healthy volunteers, HTB penetrated into the CSF in a range of concentrations experimentally proven to have protective effects in AD. These concentrations suggest that triflusal could be used in the treatment of central nervous system diseases in doses similar to those used in cardiovascular diseases. Access to the CSF compartment was characterized by a slow equilibrium rate constant and a low CSF-plasma partition coefficient.

Differential role of entorhinal and hippocampal nerve growth factor in short- and long-term memory modulation

We studied the effects of infusion of nerve growth factor (NGF) into the hippocampus and entorhinal cortex of male Wistar rats (250-300 g, N = 11-13 per group) on inhibitory avoidance retention. In order to evaluate the modulation of entorhinal and hippocampal NGF in short- and long-term memory, animals were implanted with cannulae in the CA1 area of the dorsal hippocampus or entorhinal cortex and trained in one-trial step-down inhibitory avoidance (foot shock, 0.4 mA). Retention tests were carried out 1.5 h or 24 h after training to measure short- and long-term memory, respectively. Immediately after training, rats received 5 microl NGF (0.05, 0.5 or 5.0 ng) or saline per side into the CA1 area and entorhinal cortex. The correct position of the cannulae was confirmed by histological analysis. The highest dose of NGF (5.0 ng) into the hippocampus blocked short-term memory (P < 0.05), whereas the doses of 0.5 (P < 0.05) and 5.0 ng (P < 0.01) NGF enhanced long-term memory. NGF administration into the entorhinal cortex improved long-term memory at the dose of 5.0 ng (P < 0.05) and did not alter short-term memory. Taken as a whole, our results suggest a differential modulation by entorhinal and hippocampal NGF of short- and long-term memory.

Rupatadine 10 mg and cetirizine 10 mg in seasonal allergic rhinitis: a randomised, double-blind parallel study

This randomised, double-blind, parallel-group, multicentre clinical trial evaluated the efficacy and safety of rupatadine, a new antihistamine with antiplatelet-activating factor (PAF) activity, and cetirizine in the treatment of patients with seasonal allergic rhinitis (SAR). A total 249 patients were randomised to receive rupatadine 10 mg once daily (127 patients) or cetirizine 10 mg (122 patients) for two weeks. The main efficacy variable was the mean total daily symptom score (mTDSS) and was based on the daily subjective assessment of the severity of each rhinitis symptom--nasal (runny nose, sneezing, nasal itching and nasal obstruction) and non-nasal (conjunctival itching, tearing, and pharyngeal itching)--recorded by patients in their diaries. The mTDSS was 0.7 for both treatment groups (intention to treat analysis). In the investigator's global evaluation of efficacy at the seventh day, 93.3% and 83.7% patients in the rupatadine and cetirizine groups, respectively, showed some or great improvement (p = 0.022). In the per protocol analysis (n = 181), runny nose at the seventh day of treatment was absent or mild in 81.1% of patients in the rupatadine group and in 68.6% of patients in the cetirizine group (p = 0.029). In any case statistical significance was not maintained at the second week. Overall, all treatments were well tolerated. Adverse events (AEs) were similar in both treatment groups, i.e. headache, somnolence and fatigue/asthenia as the most often reported. Somnolence was reported in 9.6% and 8.5% of patients treated with rupatadine or cetirizine, respectively. The most reported AEs (67%) were mild in intensity. Our results suggest that rupatadine 10 mg may be a valuable and safe alternative for the symptomatic treatment of SAR.

Memory consolidation induces N-methyl-d-aspartic acid-receptor- and Ca2+/calmodulin-dependent protein kinase II-dependent modifications in α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor properties

The N-methyl-D-aspartic acid (NMDA) receptor-dependent activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) is necessary for induction of the long-term potentiation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated responses in the CA1 region of the hippocampus, a putative model for learning and memory. We analyzed the interplay among NMDA receptor, CaMKII and AMPA receptor during consolidation of the memory for an inhibitory avoidance learning task in the rat. Bilateral intra-CA1 infusion of the NMDA receptor antagonist D-(-)-2-amino-5-phosphonopentanoic acid (AP5) or of the CaMKII inhibitor 2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)] amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) (KN-93) immediately after step-down inhibitory avoidance training hindered memory consolidation. Learning of the avoidance response induced the NMDA receptor-dependent translocation of alphaCaMKII to a postsynaptic density-enriched fraction isolated from dorsal CA1 and the autophosphorylation of this kinase at Thr-286. Step-down inhibitory avoidance training increased the quantity of GluR1 and GluR2/3 AMPA receptor subunits and the phosphorylation of GluR1 at Ser-831 but not at Ser-845 in CA1 postsynaptic densities. The intra-CA1 infusion of KN-93 and AP5 blocked the increases in GluR1 and GluR2/3 levels and the phosphorylation of GluR1 brought on by step-down inhibitory avoidance training. Our data suggest that step-down inhibitory avoidance learning promotes the learning-specific and NMDA receptor-dependent activation of CaMKII in the CA1 region of the dorsal hippocampus and that this activation is necessary for phosphorylation and translocation of AMPA receptor to the postsynaptic densities, similarly to what happens during long-term potentiation.

In vitro biocompatibility assessment of poly($epsiv;-caprolactone) films using L929 mouse fibroblasts

Biodegradable and biocompatible materials are the basis for tissue engineering. As an initial step for developing vascular grafts, the in vitro biocompatibility of poly(epsilon-caprolactone) (PCL), recently suggested for several clinical applications, was evaluated in this study using L929 mouse fibroblasts. Different cellular aspects were analyzed in order to know the cell viability during cell culture on PCL films: adhesion, proliferation, morphology, LDH release and mitochondrial function. Since topography and other surface characteristics of materials play an essential part in cell adhesion, PCL membranes with either smooth or rough surface were prepared, characterized and used to carry out cell cultures. During short culture times, PCL produced a significant stimulation of mitochondrial activity evaluated by reduction of the MTT reagent. The results provide evidences of good adhesion, growth, viability, morphology and mitochondrial activity of cells on PCL films. Therefore, it can be concluded that PCL is a suitable and biocompatible material as a scaffold for vascular graft development.

Structure-Related Oxidative Damage in Rat Brain After Acute and Chronic Electroshock

The role of oxidative stress in electroconvulsive therapy-related effects is not well studied. The purpose of this study was to determine oxidative stress parameters in several brain structures after a single electroconvulsive seizure or multiple electroconvulsive seizures. Rats were given either a single electroconvulsive shock or a series of eight electroconvulsive shocks. Brain regions were isolated, and levels of oxidative stress in the brain tissue (cortex, hippocampus, striatum and cerebellum) were measured. We demonstrated a decrease in lipid peroxidation and protein carbonyls in the hippocampus, cerebellum, and striatum several times after a single electroconvulsive shock or multiple electroconvulsive shocks. In contrast, lipid peroxidation increases both after a single electroconvulsive shock or multiple electroconvulsive shocks in cortex. In conclusion, we demonstrate an increase in oxidative damage in cortex, in contrast to a reduction of oxidative damage in hippocampus, striatum, and cerebellum.

A randomized, double-blind, parallel-group study, comparing the efficacy and safety of rupatadine (20 and 10 mg), a new PAF and H1 receptor-specific histamine antagonist, to loratadine 10 mg in the treatment of seasonal allergic rhinitis

BACKGROUND

The main objective of this randomized, double-blind, parallel-group, comparative study was to assess the efficacy and safety of rupatadine 10 mg (R10) and 20 mg (R20) administered once-daily for two weeks compared with those of loratadine 10 mg (L10) in the treatment of seasonal allergic rhinitis (SAR).

METHODS

A total of 339 SAR patients were randomized to receive R20 (111 patients), R10 (112 patients) or L10 (116 patients). The main efficacy variable was the mean total daily symptom score (mTDSS) based on the daily subjective assessment of the severity of rhinitis symptoms--rhinorrhea, sneezing, nasal itching, nasal obstruction, conjunctival itching, tearing and pharyngeal itching--recorded by patients.

RESULTS

The mTDSS was significantly lower in the groups treated with R20 (0.80 +/- 0.46) and R10 (0.85 +/- 0.52) than in the group treated with L10 (0.92 +/- 0.51) by protocol analysis (p = 0.03) but not by intention-to-treat analysis. The secondary variables used to assess efficacy (mDSS, DSSmax, CSS and TCSS) also showed significantly milder symptoms in patients treated with R20 and R10, particularly in sneezing and nasal itching. All treatments were well tolerated and no serious adverse events were recorded. Headache was the most frequent non-serious adverse event, and these did not show significant differences between treatments at similar dose levels. Somnolence was more frequent in R20 than in the other two groups.

CONCLUSIONS

The present results suggest that rupatadine 10 mg a day may be a valuable and safe alternative for the symptomatic treatment of seasonal allergic rhinitis.

Participation of hippocampal nicotinic receptors in acquisition, consolidation and retrieval of memory for one trial inhibitory avoidance in rats

One-trial step-down inhibitory avoidance in rats involves the activation of two separate memory types, a short-term system (STM) that lasts 3-6 h, and a long-term system (LTM) that takes 3-6 h to be formed and lasts for many days or even months. Here we investigate the effect of nicotinic receptor (nAChR) ligands infused bilaterally in the hippocampus on STM and LTM formation and on LTM retrieval of this task. Rats were implanted with chronic cannulae in the CA1 region of the dorsal hippocampus, trained using a 0.5 mA foot shock, and tested twice, first 1.5 h after training to measure STM, and again at 24 h to measure LTM. The drugs used were the nAChR antagonists, mecamylamine (1, 3 and 10 microg/side) and dihydro-beta-erythroidine (DHbetaE; 2, 6 and 18 microg/side) and the agonist, nicotine (0.6, 1 and 3 microg/side). They were given either 15 min before training, immediately after training or 15 min prior to LTM retrieval. Mecamylamine and DHbetaE impaired and nicotine enhanced STM, LTM and retrieval similarly. The results indicate that nAChRs in CA1 participate in the regulation of both STM and LTM formation, and on the retrieval of LTM.

Src kinase activity is required for avoidance memory formation and recall

Using 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-D]pyrimidine (PP2), a specific inhibitor of the Src family of tyrosine kinases, here we show a direct involvement of these enzymes in memory formation and recall. When infused into the CA1 region of the dorsal hippocampus, immediately or 30 min after training rats in a one-trial inhibitory avoidance task, PP2 but not its inactive analog 4-amino-7-phenylpyrazol[3,4-D]pyrimidine (PP3), blocked short- (STM) and long-term memory (LTM) formation, as tested 2 or 24 h post-training, respectively. PP2 had no effect on STM when given at 60 min post-training or on LTM when administered at 60, 120 or 180 min after the training session, but blocked memory recall when infused into CA1 15 min before a LTM expression test. Hence, activity of the Src family of tyrosine kinases is required in the CA1 region of the rat dorsal hippocampus for the normal formation and retrieval of one-trial inhibitory avoidance memory.

Changes in physical and biological soil quality indicators in a tropical crop system (Havana, Cuba) in response to different agroecological management practices

The objective of our study was to assess the response of physical (aggregate stability and bulk density) and biological (enzyme activities and microbial biomass) soil quality indicators to the adoption of agroecological management practices, such as the planting of forage species (forage area) and the rotation of local crops (polycrop area), carried out in a representative tropical pasture on an integrated livestock-crop farm. The pasture system was used as control (pasture area). In all three areas, the values of water-soluble C were higher in the rainy season compared to the dry season. Pasture and forage areas had the highest percentage of stable aggregates in the rainy season, while polycrops developed soils with less stable aggregates. Soil bulk density was lower in the pasture and forage areas than in the polycrop area. In the pasture area, the microbial biomass C values, dehydrogenase, urease, protease-BAA, acid phosphatase, and beta-glucosidase activities were higher than in the forage and polycrop areas, particularly in the dry season. The highest increase in the microbial biomass C in the rainy season, with respect to the dry season, was recorded in the pasture area (about 1.2-fold). In conclusion, the planting of forage species can be considered an effective practice for carrying out sustainable, integrated livestock-crop systems, due to its general maintenance of soil quality, while the adoption of polycrop rotations appears to be less favorable because it decreases soil quality.

Efficacy of flutrimazole 1% powder in the treatment of tinea pedis

The aim of the study was to compare the efficacy and tolerability of flutrimazole 1% powder vs. bifonazole 1% powder in treating tinea pedis. A multicentre, double blind, randomized, parallel and comparative study was conducted. Two hundred and twenty-two patients with clinically and mycologically confirmed tinea pedis were randomized to flutrimazole (n = 136) or bifonazole (n = 138) 1% powder applied twice daily for 4 weeks. The corresponding clinical cure rates were assessed at 2 and 4 weeks of treatment, and the global (clinical and mycological) cure rates were determined at the fourth week. Clinical cure rates were 83.5 and 82.4% for flutrimazole and bifonazole, respectively (95% CI: -0.0806 to 0.1009). Global cure rates were observed in 65.3 and 70.1% of patients treated with flutrimazole and bifonazole, respectively (95% CI: -0.0828 to 0.1779). Three non serious adverse events at the application site--itching (one patient per group) and dishydrotic eczema (one patient treated with flutrimazole)--were recorded during the study. These results support that flutrimazol 1% powder applied twice daily for a duration of 4 weeks is highly effective in the treatment of tinea pedis, showing a similar therapeutic profile with that of bifonazole 1% powder.

AMPA/kainate and group-I metabotropic receptor antagonists infused into different brain areas impair memory formation of inhibitory avoidance in rats

Several lines of evidence suggest that glutamate receptors are involved in memory processing. To examine the role of non-N-methyl-D-aspartate (non-NMDA) glutamate receptors on memory consolidation, rats were bilaterally implanted with cannulae aimed at the CA1 region of the dorsal hippocampus (CA1), entorhinal cortex (ENTO), posterior parietal cortex (PPC) or the basolateral nucleus of the amygdala (BLA), and trained in a one-trial step-down inhibitory avoidance task. At different times after training, the alpha-amino 3-hydroxy-5 methyl 4-isoxazole propionate (AMPA) receptor blocker, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (1.0 microg/side), or the metabotropic type-I receptor antagonist, 2-amino-3-phosphonopropionic acid (AP3) (1.0 microg/side), were infused into the above-mentioned structures. CNQX produced retrograde amnesia when infused into BLA or CA1 0, 30, 90 or 180 min post-training but not at later times. AP3 blocked memory consolidation when administered into CA1 0, 30 or 180 min post-training, while in BLA, it was amnestic only when given 0 or 30 min after the training session. CNQX and AP3 had no effect on memory when administered into ENTO or PPC at any time. Our data suggest that the consolidation of the avoidance memory requires intact non-NMDA receptor function in the hippocampus and the basolateral nucleus of the amygdala, but not necessarily in the entorhinal and parietal cortex, for long periods after training.

Stress hormones enhance retrieval of fear conditioning acquired either one day or many months before

It has been known for years that systemic administration of the stress hormones, adrenocorticotrophin (ACTH), lysine-vasopressin, adrenaline, or beta-endorphin, enhances retrieval of aversive behaviours acquired one or a few days before. Here we show that the pre-test i.p. injection of the hormones in rats can also enhance retrieval when given months after the original training. The effectiveness of the treatments changed with time. When animals were tested 3 months after training the hormones enhanced retrieval only at doses five times higher than those needed 1 day after training. Between 6 and 9 months from training the hormones either lost their effect (vasopressin, beta-endorphin) or actually inhibited retrieval (ACTH, adrenaline). The effects of the hormones cannot be explained by a decrease in locomotor activity: none of the treatments had such an effect, as measured in an open field. However, when the animals were tested between 12 and 19 months after training, the hormones once again became as effective as they had been 1 day after training. This was so in spite of the fact that control retention levels became very low with age, probably as a result of extinction. The oscillation of the sensitivity of retrieval to the hormones does not appear to depend on changes in anxiety levels with ageing or to effects of the hormones on locomotor activity.

Bupropion and sertraline enhance retrieval of recent and remote long-term memory in rats

Wistar rats were trained in step-down inhibitory avoidance at the age of 3 months, and tested for retrieval either 1 day later or 3, 6, 9, 12, 15 or 19 months later, when the animals were 6, 9, 12, 15, 18 or 22 months old, respectively. Bupropion (20 or 60 mg/kg) and sertraline (3.3 or 10 mg/kg) given orally 6 or 3 h before retention testing, respectively, enhanced retrieval of this task at all training-test intervals, despite the fact that retrieval at the longest intervals was practically not seen in control animals. The effect cannot be explained by influences of the drugs on locomotor activity; the treatments had no effect on open field behaviour at the age of 3, 8 or 21 months. The findings may be relevant to the use of these drugs as cognitive enhancers in elderly subjects.

Modulation of working memory and of long- but not short-term memory by cholinergic mechanisms in the basolateral amygdala

Male Wistar rats were exposed to one-trial step-down inhibitory avoidance training using a 0.5 mA footshock. Through bilaterally implanted indwelling cannulae, they received bilateral 0.5 microl infusions of saline, oxotremorine (0.06 or 0.3 microg) or scopolamine (0.25 or 2.0 microg) into the basolateral complex of the amygdaloid nucleus (BLA). Infusions were either 10 min before training (experiment 1) or 4 min after training (experiment 2). In experiment 1, the animals were tested three times: first for working memory (WM) 2 s after training, then for short-term memory (STM) 1.5 h later, and finally for long-term memory (LTM) 24 h later. Oxotremorine enhanced and scopolamine depressed WM and LTM while leaving STM unaffected. In experiment 2, the treatments were given after WM was presumably over. Again, oxotremorine again enhanced and scopolamine depressed LTM, and neither had any effect on STM. The results fit with the suggestion by Beninger and his co-workers that cholinergic synapses in the BLA regulate WM, generalize that finding to a different task, and show that this mechanism uses muscarinic receptors. In addition, they indicate that the well-known effects of intra-amygdala oxotremorine and scopolamine on LTM are independent of those that the drugs have on WM.

Effects of posttraining treatments in the posterior cingulate cortex on short- and long-term memory for inhibitory avoidance in rats

Adult male Wistar rats were bilaterally implanted with indwelling cannulae in the caudal region of the posterior cingulate cortex. After recovery, animals were trained in a step-down inhibitory avoidance task (3.0-s, 0.4-mA foot shock) and received, right after training, a 0.5-microl infusion of vehicle (phosphate-buffered saline, pH 7.4), of the GABA(A) receptor agonist muscimol (0.1 or 0.5 microg), of the cAMP-dependent protein kinase (PKA) stimulant Sp-cAMPS (0.1 or 0.5 microg), or of the PKA inhibitor Rp-cAMPS (0.1 or 0.5 microg). Animals were tested twice, 1.5 h and, again, 24 h after training, in order to examine the effects of these agents on short- and long-term memory, respectively. Muscimol (0.5 but not 0.1 microg) hindered retention for both short- and long-term memory (p <.05). Rp-cAMPS (0.1 or 0.5 microg) hindered retention for short-term memory (p <.05). In addition, these animals showed lower, but not significantly lower, latencies than controls in the test session for long-term memory (p >.10). A trend toward an amnesic effect on long-term memory was also observed after Sp-cAMPS infusion at 0.1 microg (p <.10). These results show that strong stimulation of GABAergic synapses in the caudal region of the rat posterior cingulate cortex right after training impairs short- and long-term memory (the latter less dramatically). The same occurs by inhibiting PKA activity with regard to STM and possibly to LTM.

LY294002, an inhibitor of phosphoinositide 3-kinase given into rat hippocampus impairs acquisition, consolidation and retrieval of memory for one-trial step-down inhibitory avoidance

Adult male Wistar rats were bilaterally implanted with indwelling cannulae in the CA1 region of the dorsal hippocampus. Once recovered from surgery, animals were submitted to one session of step-down inhibitory avoidance training (3.0 s, 0.4 mA footshock). Animals received a 0.5-microl infusion of saline, or of LY294002 (5, 50 or 500 microM), an inhibitor of the phosphoinositide 3-kinase (PI 3-K) family. Infusions were given 10 min before training, immediately post-training or 10 min prior to a 24-h retention test. In the pre- and post-training groups, the animals were tested twice: at 1.5 and 24 h after training, for short- (STM) and long-term memory (LTM), respectively. Pre- and post-training infusion of the drug inhibited both STM and LTM. Pre-test infusions impaired LTM retrieval. The effects can not be attributed to influences on locomotor, exploratory, pro- or anti-conflict behaviour, since LY294002 had no influence on elevated plus-maze behaviour. The results suggest that hippocampal PI 3-K is necessary for memory acquisition, consolidation and retrieval of the consolidation of step-down inhibitory avoidance in rats. This could be due to an interaction with the N-methyl-d-aspartate (NMDA) receptor complex or with activity of the extracellularly regulated protein kinase (ERK)-Ras signalling pathway.

The ubiquitin-proteasome cascade is required for mammalian long-term memory formation

It has been recently demonstrated that ubiquitin-proteasome-mediated proteolysis is required for long-term synaptic facilitation in Aplysia. Here we show that the hippocampal blockade of this proteolytic pathway is also required for the formation of long-term memory in the rat. Bilateral infusion of lactacystin, a specific proteasome inhibitor, to the CA1 region caused full retrograde amnesia for a one-trial inhibitory avoidance learning when given 1, 4 or 7h, but not 10 h, after training. Proteasome inhibitor I produced similar effects. In addition, inhibitory avoidance training resulted in an increased ubiquitination and 26S proteasome proteolytic activity and a decrease in the levels of IkappaB, a substrate of the ubiquitin-proteasome cascade, in hippocampus 4 h after training. Together, these findings indicate that the ubiquitin-proteasome cascade is crucial for the establishment of LTM in the behaving animal.

Retrieval of memory for fear-motivated training initiates extinction requiring protein synthesis in the rat hippocampus

Evidence that protein synthesis inhibitors induce amnesia in a variety of species and learning paradigms indicates that the consolidation of newly acquired information into stable memories requires the synthesis of new proteins. Because extinction of a response also requires acquisition of new information, extinction, like original learning, would be expected to require protein synthesis. The present experiments examined the involvement of protein synthesis in the hippocampus in the extinction of a learned fear-based response known to involve the hippocampus. Rats were trained in a one-trial inhibitory avoidance task in which they received footshock after stepping from a small platform to a grid floor. They were then given daily retention tests without footshock. The inhibitory response (e.g., remaining on the platform) gradually extinguished with repeated testing over several days. Footshock administered in a different context, instead of a retention test, prevented the extinction. Infusions of the protein synthesis inhibitor anisomycin (80 microg) into the CA1 region of the hippocampus (bilaterally) 10 min before inhibitory avoidance training impaired retention on all subsequent tests. Anisomycin infused into the hippocampus immediately after the 1st retention test blocked extinction of the response. Infusions administered before the 1st retention test induced a temporary (i.e., 1 day) reduction in retention performance and blocked subsequent extinction. These findings are consistent with other evidence that anisomycin blocks both the consolidation of original learning and extinction.

Simultaneous modulation of retrieval by dopaminergic D(1), beta-noradrenergic, serotonergic-1A and cholinergic muscarinic receptors in cortical structures of the rat

Retrieval of inhibitory avoidance has been recently shown to require intact glutamate receptors, protein kinases A and C and mitogen-activated protein kinase in the CA1 region of the rat hippocampus and in the entorhinal, posterior parietal and anterior cingulate cortex. These enzymatic activities are known to be modulated by dopamine D(1), beta-noradrenergic, 5HT1A and cholinergic muscarinic receptors. Here we study the effect on retrieval of this task of well-known agonists and antagonists of these receptors infused in the same brain cortical regions and into the basolateral amygdala, in rats. The drugs used were SKF38393 (D(1) agonist), noradrenaline, 8-HO-DPAT (5HT1A agonist), oxotremorine (muscarinic agonist), SCH23390 (D(1) antagonist), timolol (beta antagonist), NAN-190 (5HT1A antagonist) and scopolamine (muscarinic antagonist). All were studied at two different dose levels. The localised infusion of SKF38393, noradrenaline, NAN-190 and oxotremorine into any of the cortical structures mentioned 10 min prior to a 24-h retention test session of one-trial step-down inhibitory avoidance enhanced retention test performance. SCH2330, timolol, 8-HO-DPAT and scopolamine hindered retention test performance. In the basolateral amygdala only an enhancing effect of noradrenaline and an inhibitory effect of timolol were seen. Three hours after the infusions, retention test performance returned to normal in all cases. None of the treatments affected locomotion or rearing in an open field or behaviour in the elevated plus maze. Therefore, their effects on retention testing can be attributed to an influence on retrieval. In conclusion, memory retrieval of this apparently simple task requires the participation of CA1, entorhinal, posterior parietal and anterior cingulate cortex, and is strongly modulated by, dopaminergic D(1), beta-noradrenergic, muscarinic cholinergic and 5HT1A receptors in the four areas. The first three types of receptor enhance, and the latter inhibits, retrieval. Only beta-adrenoceptors appears to be involved in the modulation of retrieval of this task by the amygdala. The results bear on the well-known influence of emotion and mood on retrieval, and indicate that this involves many areas of the brain simultaneously. In addition, the results point to similarities and differences between the modulatory mechanisms that affect retrieval and those involved in the consolidation of the same task.