Cilastatin as a Potential Anti-Inflammatory and Neuroprotective Treatment in the Management of Glaucoma.

Glaucoma is a neurodegenerative disease that causes blindness. In this study, we aimed to evaluate the protective role of cilastatin (CIL), generally used in the treatment of nephropathologies associated with inflammation, in an experimental mouse model based on unilateral (left) laser-induced ocular hypertension (OHT). Male Swiss mice were administered CIL daily (300 mg/kg, i.p.) two days before OHT surgery until sacrifice 3 or 7 days later. Intraocular Pressure (IOP), as well as retinal ganglion cell (RGC) survival, was registered, and the inflammatory responses of macroglial and microglial cells were studied via immunohistochemical techniques. Results from OHT eyes were compared to normotensive contralateral (CONTRA) and naïve control eyes considering nine retinal areas and all retinal layers. OHT successfully increased IOP values in OHT eyes but not in CONTRA eyes; CIL did not affect IOP values. Surgery induced a higher loss of RGCs in OHT eyes than in CONTRA eyes, while CIL attenuated this loss. Similarly, surgery increased macroglial and microglial activation in OHT eyes and to a lesser extent in CONTRA eyes; CIL prevented both macroglial and microglial activation in OHT and CONTRA eyes. Therefore, CIL arises as a potential effective strategy to reduce OHT-associated damage in the retina of experimental mice.

Retinal Molecular Changes Are Associated with Neuroinflammation and Loss of RGCs in an Experimental Model of Glaucoma.

Signaling mediated by cytokines and chemokines is involved in glaucoma-associated neuroinflammation and in the damage of retinal ganglion cells (RGCs). Using multiplexed immunoassay and immunohistochemical techniques in a glaucoma mouse model at different time points after ocular hypertension (OHT), we analyzed (i) the expression of pro-inflammatory cytokines, anti-inflammatory cytokines, BDNF, VEGF, and fractalkine; and (ii) the number of Brn3a+ RGCs. In OHT eyes, there was an upregulation of (i) IFN-γ at days 3, 5, and 15; (ii) IL-4 at days 1, 3, 5, and 7 and IL-10 at days 3 and 5 (coinciding with downregulation of IL1-ß at days 1, 5, and 7); (iii) IL-6 at days 1, 3, and 5; (iv) fractalkine and VEGF at day 1; and (v) BDNF at days 1, 3, 7, and 15. In contralateral eyes, there were (i) an upregulation of IL-1ß at days 1 and 3 and a downregulation at day 7, coinciding with the downregulation of IL4 at days 3 and 5 and the upregulation at day 7; (ii) an upregulation of IL-6 at days 1, 5, and 7 and a downregulation at 15 days; (iii) an upregulation of IL-10 at days 3 and 7; and (iv) an upregulation of IL-17 at day 15. In OHT eyes, there was a reduction in the Brn3a+ RGCs number at days 3, 5, 7, and 15. OHT changes cytokine levels in both OHT and contralateral eyes at different time points after OHT induction, confirming the immune system involvement in glaucomatous neurodegeneration.

Probiotics in digestive, emotional, and pain-related disorders.

In recent years, interest in the relationship between gut microbiota and disease states has grown considerably. Indeed, several strategies have been employed to modify the microbiome through the administration of different diets, by the administration of antibiotics or probiotics, or even by transplantation of feces. In the present manuscript, we focus specifically on the potential application of probiotics, which seem to be a safe strategy, in the management of digestive, pain, and emotional disorders. We present evidence from animal models and human studies, notwithstanding that translation to clinic still deserves further investigation. The microbiome influences gut functions as well as neurological activity by a variety of mechanisms, which are also discussed. The design and performance of larger trials is urgently needed to verify whether these new strategies might be useful not only for the treatment of disorders affecting the gastrointestinal tract but also in the management of emotional and pain disorders not directly related to the gut.

Early maternal deprivation enhances voluntary alcohol intake induced by exposure to stressful events later in life.

In the present study, we aimed to assess the impact of early life stress, in the form of early maternal deprivation (MD, 24 h on postnatal day, pnd, 9), on voluntary alcohol intake in adolescent male and female Wistar rats. During adolescence, from pnd 28 to pnd 50, voluntary ethanol intake (20%, v/v) was investigated using the two-bottle free choice paradigm. To better understand the relationship between stress and alcohol consumption, voluntary alcohol intake was also evaluated following additional stressful events later in life, that is, a week of alcohol cessation and a week of alcohol cessation combined with exposure to restraint stress. Female animals consumed more alcohol than males only after a second episode of alcohol cessation combined with restraint stress. MD did not affect baseline voluntary alcohol intake but increased voluntary alcohol intake after stress exposure, indicating that MD may render animals more vulnerable to the effects of stress on alcohol intake. During adolescence, when animals had free access to alcohol, MD animals showed lower body weight gain but a higher growth rate than control animals. Moreover, the higher growth rate was accompanied by a decrease in food intake, suggesting an altered metabolic regulation in MD animals that may interact with alcohol intake.

Consequences of early life stress on the expression of endocannabinoid-related genes in the rat brain.

The endocannabinoid system is involved in several physiological and pathological states including anxiety, depression, addiction and other neuropsychiatric disorders. Evidence from human and rodent studies suggests that exposure to early life stress may increase the risk of psychopathology later in life. Indeed, maternal deprivation (MD) (24 h at postnatal day 9) in rats induces behavioural alterations associated with depressive-like and psychotic-like symptoms, as well as important changes in the endocannabinoid system. As most neuropsychiatric disorders first appear at adolescence, and show remarkable sexual dimorphisms in their prevalence and severity, in the present study, we analysed the gene expression of the main components of the brain cannabinoid system in adolescent (postnatal day 46) Wistar male and female rats reared under standard conditions or exposed to MD. For this, we analysed, by real-time quantitative PCR, the expression of genes encoding for CB1 and CB2 receptors, TRPV1 and GPR55 (Cnr1, Cnr2a, Cnr2b, Trpv1, and Gpr55), for the major enzymes of synthesis, N-acyl phosphatidyl-ethanolamine phospholipase D (NAPE-PLD) and diacylglycerol lipase (DAGL) (Nape-pld, Dagla and Daglb), and degradation, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) (Faah, Magl and Cox-2), in specific brain regions, that is, the frontal cortex, ventral and dorsal striatum, dorsal hippocampus and amygdala. In males, MD increased the genetic expression of all the genes studied within the frontal cortex, whereas in females such an increase was observed only in the hippocampus. In conclusion, the endocannabinoid system is sensitive to early life stress at the gene expression level in a sex-dependent and region-dependent manner, and these changes are already evident in the adolescent brain.

Sex-dependent changes in brain CB1R expression and functionality and immune CB2R expression as a consequence of maternal deprivation and adolescent cocaine exposure.

Early life stress has been associated with several psychiatric disorders, including drug addiction. Actually, maternal deprivation (MD) alters the endocannabinoid system, which participates in motivation and reward for drugs, including cocaine. At youth, the rate of cocaine abuse is alarmingly increasing. Herein, we have investigated the consequences of MD and/or adolescent cocaine exposure in brain CB1Rs and CB2Rs in immune tissues. Control and maternally deprived (24h on postnatal day, pnd, 9) male and female Wistar rats were administered cocaine (8mg/kg/day) or saline during adolescence (pnd 28-42). At adulthood, [(3)H]-CP-55,940 autoradiographic binding was employed for the analysis of CB1R density and CP-55,940-stimulated [(35)S]-GTPgammaS binding for CB1R functionality; CB2R expression was analyzed by Western blotting. Sex differences in CB1R expression and functionality were found, and MD induced important and enduring sex-dependent changes. In addition, the plastic changes induced by adolescent cocaine administration in brain CB1Rs were differentially influenced by early life events. MD increased spleen CB2R expression while adolescent cocaine administration attenuated this effect; cocaine exposure also diminished CB2R expression in bone marrow. Present findings provide evidence for changes in brain CB1R expression and functionality and immune CB2R expression as a consequence of early life stress and adolescent cocaine exposure, and indicate functional interactions between both treatments, which in many regions differ between males and females.

The role of the endocannabinoid system in eating disorders: pharmacological implications.

The endocannabinoid (eCB) system is a widespread intercellular signalling mechanism that plays a critical role in body homoeostasis. It is located in key points involved in food intake and energy expenditure, coordinating all the players involved in energy balance. As such, it has come to be seen as an interesting target for the management of diseases characterized by an imbalanced energy homoeostasis, such as obesity and eating disorders. The aetiology of eating disorders and the molecular systems involved are still largely a mystery. Research has focused on brain circuits where the eCB system plays an important role, such as those related to feeding behaviour and the rewarding properties of food. Accordingly, recent findings have suggested a deregulation of the eCB system in eating disorders. At present, cannabinoid agonists are safe and effective tools in the management of diseases in which weight gain is needed, for example cachexia in AIDS patients. However, studies on the potential therapeutic validity of cannabinoids in eating disorders are scarce and inconclusive. Taken together, all these considerations warrant more preclinical and clinical investigations in the role of the eCB system in eating disorders. Eventually, they may provide novel pharmacological approaches for the treatment of these diseases.

Upregulation of TLR4/MyD88 pathway in alcohol-induced Wernicke's encephalopathy: Findings in preclinical models and in a postmortem human case.

Wernicke's encephalopathy (WE) is a neurologic disease caused by vitamin B1 or thiamine deficiency (TD), being the alcohol use disorder its main risk factor. WE patients present limiting motor, cognitive, and emotional alterations related to a selective cerebral vulnerability. Neuroinflammation has been proposed to be one of the phenomena that contribute to brain damage. Our previous studies provide evidence for the involvement of the innate immune receptor Toll-like (TLR)4 in the inflammatory response induced in the frontal cortex and cerebellum in TD animal models (animals fed with TD diet [TDD] and receiving pyrithiamine). Nevertheless, the effects of the combination of chronic alcohol consumption and TD on TLR4 and their specific contribution to the pathogenesis of WE are currently unknown. In addition, no studies on TLR4 have been conducted on WE patients since brains from these patients are difficult to achieve. Here, we used rat models of chronic alcohol (CA; 9 months of forced consumption of 20% (w/v) alcohol), TD hit (TDD + daily 0.25 mg/kg i.p. pyrithiamine during 12 days), or combined treatment (CA + TDD) to check the activation of the proinflammatory TLR4/MyD88 pathway and related markers in the frontal cortex and the cerebellum. In addition, we characterized for the first time the TLR4 and its coreceptor MyD88 signature, along with other markers of this proinflammatory signaling such as phospo-NFκB p65 and IκBα, in the postmortem human frontal cortex and cerebellum (gray and white matter) of an alcohol-induced WE patient, comparing it with negative (no disease) and positive (aged brain with Alzheimer's disease) control subjects for neuroinflammation. We found an increase in the cortical TLR4 and its adaptor molecule MyD88, together with an upregulation of the proinflammatory signaling molecules p-NF-ĸB and IĸBα in the CA + TDD animal model. In the patient diagnosed with alcohol-induced WE, we observed cortical and cerebellar upregulation of the TLR4/MyD88 pathway. Hence, our findings provide evidence, both in the animal model and the human postmortem brain, of the upregulation of the TLR4/MyD88 proinflammatory pathway in alcohol consumption-related WE.

Differential response to specific 5-Ht(7) versus whole-serotonergic drugs in rat forebrains: a phMRI study.

We recently suggested that serotonin 7 (5-Ht7) receptors may play a role in ADHD-like symptoms, at least in animal models. A mixed 5-Ht(1a/7) agonist, 8-OH-DPAT, counteracted the augmented levels of basal impulsivity, observed after treatment with a selective 5-Ht7 antagonist, SB269970 (Leo et al., 2009). In the present study, these serotonergic compounds were investigated by pharmacological magnetic resonance imaging (phMRI) at 4.7 T in adult isoflurane-anaesthetized rats. Axial echo-planar images were collected from the prefrontal cortex (PFC), ventral (nucleus accumbens, NAcc) and dorsal (dStr) striata, the hippocampus and the thalamus. After consecutive image collection for 30 min (50 baseline images), adult rats received either SB269970 (3mg/kg), 8-OH-DPAT (0.06 mg/kg) or saline intra-peritoneally (i.p.) via a remote cannula; the images were then collected for further 30 min (50 post-treatment images). Data were analysed 1) through an activation map generated on brain templates, obtained by using animals from each experimental group; 2) by a two-way ANOVA for the evaluation of temporal profiles, extracted within selected ROIs of each animal. Both compounds increased the BOLD signal in the areas of interest: SB269970, the selective 5-Ht7 antagonist, induced a significant effect in the PFC, particularly the orbital (oPFC) region, and in the NAcc. This effect started 6 to 12 min after drug administration, reached a maximum (+2.8%/+2.3%) at 12 to 18 min, and then moved to the dorsal thalamic nuclei. In contrast, the effects of 8-OH-DPAT were first observed in midline thalamic nuclei, and later appeared in forebrain regions: its effects were modest and transient within the NAcc and oPFC (+1.7% at 18 to 24 min after injection), whereas they were higher and long-lasting in the dStr and PFC, specifically the medial (mPFC) region (+3.1%/+4.0% from 15 min after drug administration onwards). The brain BOLD changes, reported as a consequence of selective 5-Ht7 antagonist administration, seemed restricted to the oPFC, NAcc and dorso-thalamic circuits, whereas the non-selective blockade of serotonergic receptors affected the mPFC, dStr and mid(line)-thalamic circuitry. The present findings revealed two differential serotonergic sub-pathways, as evidenced by the detection of physiological vascular feedback and/or neuronal activation.

Cerebellar and cortical TLR4 activation and behavioral impairments in Wernicke-Korsakoff Syndrome: Pharmacological effects of oleoylethanolamide.

Wernicke-Korsakoff Syndrome (WKS) is a neuropsychiatric disorder whose etiology is a thiamine deficiency (TD), with alcoholism being the main underlying cause. Previous evidence suggests the presence of initial neuroinflammation and oxidative/nitrosative stress in the physiopathology, although the specific molecular mechanisms underlying TD-induced brain damage and behavioral disabilities are unknown. We explored the specific role of the innate immune receptor TLR4 in three murine models of WKS, based on the combination of a thiamine-deficient diet and pyrithiamine injections (0.25 mg/kg, i.p.) over time. The Symptomatic Model (SM) allowed us to describe the complete neurological/neurobehavioral symptomatology over 16 days of TD. Animals showed an upregulation of the TLR4 signaling pathway both in the frontal cortex (FC) and cerebellum and clear motor impairments related with cerebellar dysfunction. However, in the Pre-Symptomatic Model (PSM), 12 days of TD induced the TLR4 pathway upregulation in the FC, which correlated with disinhibited-like behavior, but not in the cerebellum, and no motor impairments. In addition, we tested the effects of the biolipid oleoylethanolamide (OEA, 10 mg/kg, i.p., once daily, starting before any symptom of the pathology is manifested) through the Glucose-Precipitated Model (GPM), which was generated by glucose loading (5 g/kg, i.v., last day) in thiamine-deficient animals to accelerate damage. Pretreatment with OEA prevented the TLR4-induced signature in the FC, as well as an underlying incipient memory disability and disinhibited-like behavior. This study suggests a key role for TLR4 in TD-induced neuroinflammation in the FC and cerebellum, and it reveals different vulnerability of these brain regions in WKS over time. Pre-treatment with OEA counteracts TD-induced TLR4-associated neuroinflammation and may serve as co-adjuvant therapy to prevent WKS-induced neurobehavioral alterations.

Is Saffron Able to Prevent the Dysregulation of Retinal Cytokines Induced by Ocular Hypertension in Mice?

Cytokine- and chemokine-mediated signalling is involved in the neuroinflammatory process that leads to retinal ganglion cell (RGC) damage in glaucoma. Substances with anti-inflammatory properties could decrease these cytokines and chemokines and thus prevent RGC death. The authors of this study analysed the anti-inflammatory effect of a hydrophilic saffron extract standardized to 3% crocin content, focusing on the regulation of cytokine and chemokine production, in a mouse model of unilateral laser-induced ocular hypertension (OHT). We demonstrated that following saffron treatment, most of the concentration of proinflammatory cytokines (IL-1ß, IFN-γ, TNF-α, and IL-17), anti-inflammatory cytokines (IL-4 and IL-10), Brain-derived Neurotrophic Factor (BDNF), Vascular Endothelial Growth Factor (VEGF), and fractalkine were unaffected in response to laser-induced OHT in both the OHT eye and its contralateral eye. Only IL-6 levels were significantly increased in the OHT eye one day after laser induction compared with the control group. These results differed from those observed in animals subjected to unilateral OHT and not treated with saffron, where changes in cytokine levels occurred in both eyes. Therefore, saffron extract regulates the production of proinflammatory cytokines, VEGF, and fractalkine induced by increasing intraocular pressure (IOP), protecting the retina from inflammation. These results indicate that saffron could be beneficial in glaucoma by helping to reduce the inflammatory process.

Detrimental psychophysiological effects of early maternal deprivation in adolescent and adult rodents: altered responses to cannabinoid exposure.

Environmental rearing conditions during the neonatal period are critical for the establishment of neurobiological factors controlling behavior and stress responsiveness. Early maternal deprivation (MD), consisting of a single 24-h maternal deprivation episode during early neonatal life, has been proposed as an animal model for certain psychopathologies including anxiety, depression and schizophrenic-related disorders. Despite first onset of mental disorders usually occur during adolescence, characterization of MD has been mostly developed in adult animals. We review here a series of experiments that were conducted on rats and mice, in which we analyzed the psychoimmunoendocrine outcomes of MD at both adolescence and adulthood. As a whole our results indicate that MD might promote a depressive-like trait that may be present from adolescence to maturity. Maternally deprived adolescent animals also displayed altered locomotor responses, a reduced interest for social investigation and seemed prone for impulsive behavior. Therefore, MD in rodents is further confirmed as a suitable animal model for the study of neuropsychiatric disorders that might become evident during adolescence. Given the increasing consumption of cannabis derivatives among the juvenile population and the reported comorbidity of neuropsychiatric symptoms with cannabis abuse, we also discuss our results indicating altered responses of maternally deprived adolescent animals to cannabinoid compounds.

Peculiar response to methylphenidate in adolescent compared to adult rats: a phMRI study.

RATIONALE: Adolescent rodents differ markedly from adults in several neuro-behavioural parameters. Moreover, 'paradoxical' responses to psychostimulants have been reported at this age. OBJECTIVES: Thus, we investigated the responses of adolescent (post-natal day, PND, 34 to 43) and adult (PND >60) Sprague-Dawley male rats to the psychostimulant drug methylphenidate (MPH). We used pharmacological magnetic resonance imaging (phMRI) performed at 4.7 T under isoflurane anaesthesia. Following anatomical MRI, axial gradient echo images were collected continuously. After baseline recording (32 min), animals received MPH (0 or 4 mg/kg i.p.) and were recorded for further 32 min. RESULTS: Region-specific changes in the blood-oxygenation level dependent (BOLD) signal were evident as a function of age. As expected, among adults MPH induced an increase of BOLD signal in nucleus accumbens (NAcc) and prefrontal cortex (PFC), with no effects in the hippocampus (Hip). Notably, among adolescents, MPH induced a marked and generalised decrease of BOLD signal, which occurred earlier in NAcc and PFC whilst being delayed in the Hip. Any bias in BOLD responses was excluded by the measurement of physiological parameters. CONCLUSIONS: The present findings highlight the utility of phMRI in animal models. The peculiar negative BOLD effect found in adolescent rats may be suggestive of a reduced cerebro-vascular feedback and/or an increased MPH-induced neuronal activation. Data are relevant for a better understanding of brain/behavioural regulation during adolescent development. Moreover, a greater understanding of the differences between adult and adolescent drug responses will aid in the development of a more appropriate age-specific treatment strategy.

Influence of aging and enriched environment on motor activity and emotional responses in mice.

We have evaluated different behavioral parameters in ICR (CD1) female mice of three different ages (38-39 weeks: mature; 62 weeks: late mature; 90 weeks: old), and addressed the effects of an enriched housing condition. We employed the following battery of tests: Holeboard, open field, elevated plus-maze (EPM), and forced swimming test (FST). The results suggest that aging process differentially affects diverse aspects of behavior. With respect to motor activity, late mature animals were more affected by enrichment, whereas old animals appeared to be more affected when emotional responses were considered. We propose that the diminished percentage of time in the open arms of the EPM showed by enriched mice may be indicative of decreased novelty seeking, whereas their decreased climbing behavior may indicate a reduced escape-related behavior in an inescapable situation.

Subchronic nicotine exposure in adolescence induces long-term effects on hippocampal and striatal cannabinoid-CB1 and mu-opioid receptors in rats.

There is evidence for the existence of functional interactions between nicotine and cannabinoids and opioid compounds in adult experimental animals. However, there is scarce information about these relationships in young animals. In the present study we evaluated short and long-term effects of a subchronic nicotine treatment [0.4 mg/kg daily i.p. injections from postnatal day (PND) 34 to PND 43], upon hippocampal and striatal cannabinoid-CB(1) and mu-opioid receptors in Wistar rats of both genders. Rats were sacrificed 2 h after the last nicotine injection (short-term effects, PND 43) or one month later (long-term effects, PND 75). Hippocampal and striatal cannabinoid CB(1) and mu-opioid receptors were quantified by Western blotting. The subchronic nicotine treatment induced a region-dependent long-lasting effect in cannabinoid CB(1) receptor: a significant increase in hippocampal cannabinoid CB(1) receptors and a significant decrease in striatal cannabinoid CB(1) receptors, with these effects being similar in males and females. With respect to mu-opioid receptors, subchronic nicotine induced a significant down-regulation in hippocampal and striatal mu-opioid receptors in the long-term, and within the striatum the effects were more marked in adult males than in females. The present results indicate that juvenile nicotine taking may have implications for the endocannabinoid and endogenous opioid function and for the behaviors served by those systems, this includes possible modification of the response of adults to different psychotropic drugs, i.e. cannabis and morphine/heroin when taken later in life.

Sex-dependent influence of chronic mild stress (CMS) on voluntary alcohol consumption; study of neurobiological consequences.

Alcohol use disorder and depression are highly comorbid, and both conditions exhibit important sexual dimorphisms. Here, we aimed to investigate voluntary alcohol consumption after 6weeks of chronic mild stress (CMS) in Wistar rats - employed as an animal model of depression. Male and female rats were investigated, and changes in several molecular markers were analysed in frontal cortex (FCx) and hippocampal formation (HF). CMS induced depressive-like responses in the forced swimming test - increased immobility time - in male and female animals, without affecting anhedonia (sucrose preference test) nor motor activity (holeboard); body weight gain and food intake were diminished only among CMS males. Voluntary alcohol consumption was evaluated in a two-bottle choice paradigm (ethanol 20% versus tap water) for 4 consecutive days; females exhibited a higher preference for alcohol compared to male animals. In particular, alcohol consumption was significantly higher among CMS females compared to CMS male animals. Remarkably, similar changes in both male and female animals exposed to CMS were observed regarding the expression levels of NCAM-140KDa (decrease), GFAP and CB1R expression (increase) within the FCx as well as for HF PSD-95 levels (increase). However, contrasting effects in males and females were reported in relation to synaptophysin (SYN) protein levels within the FCx, HF CB1R expression (a decrease among male animals but an increase in females); while the opposite pattern was observed for NCAM-140KDa protein levels in the HF. A decrease in CB2R expression was only observed in the HF of CMS-females. The present study suggests that male and female animals might be differentially affected by CMS regarding later voluntary alcohol consumption. In this initial approach, cortical SYN, and NCAM-140KDa, CB1R and CB2R expression within the HF have arisen as potential candidates to explain such sex differences in behaviour. However, the depression-alcoholism relationship still deserves further investigation.

Long-Term Effects of Intermittent Adolescent Alcohol Exposure in Male and Female Rats.

Alcohol is a serious public health concern that has a differential impact on individuals depending upon age and sex. Patterns of alcohol consumption have recently changed: heavy episodic drinking-known as binge-drinking-has become most popular among the youth. Herein, we aimed to investigate the consequences of intermittent adolescent alcohol consumption in male and female animals. Thus, Wistar rats were given free access to ethanol (20% in drinking water) or tap water for 2-h sessions during 3 days, and for an additional 4-h session on the 4th day; every week during adolescence, from postnatal day (pnd) 28-52. During this period, animals consumed a moderate amount of alcohol despite blood ethanol concentration (BEC) did not achieve binge-drinking levels. No withdrawal signs were observed: no changes were observed regarding anxiety-like responses in the elevated plus-maze or plasma corticosterone levels (pnd 53-54). In the novel object recognition (NOR) test (pnd 63), a significant deficit in recognition memory was observed in both male and female rats. Western Blot analyses resulted in an increase in the expression of synaptophysin in the frontal cortex (FC) of male and female animals, together with a decrease in the expression of the CB2R in the same brain region. In addition, adolescent alcohol induced, exclusively among females, a decrease in several markers of dopaminergic and serotonergic neurotransmission, in which epigenetic mechanisms, i.e., histone acetylation, might be involved. Taken together, further research is still needed to specifically correlate sex-specific brain and behavioral consequences of adolescent alcohol exposure.

Nicotine and cannabinoids: parallels, contrasts and interactions.

After a brief outline of the nicotinic and cannabinoid systems, we review the interactions between the pharmacological effects of nicotine and cannabis, two of the most widely used drugs of dependence. These drugs are increasingly taken in combination, particularly among the adolescents and young adults. The review focuses on addiction-related processes, gateway and reverse gateway theories of addiction and therapeutic implications. It then reviews studies on the important period of adolescence, an area that is in urgent need of further investigation and in which the importance of sex differences is emerging. Three other areas of research, which might be particularly relevant to the onset and/or maintenance of dependence, are then reviewed. Firstly, the effects of the two drugs on anxiety-related behaviours are discussed and then their effects on food intake and cognition, two areas in which they have contrasting effects. Certain animal studies suggest that reinforcing effects are likely to be enhanced by joint consumption of nicotine and cannabis, as also may be anxiolytic effects. If this was the case in humans, the latter might be viewed as an advantage particularly by adolescent girls, although the increased weight gain associated with cannabis would be a disadvantage. The two drugs also have opposite effects on cognition and the possibility of long-lasting cognitive impairments resulting from adolescent consumption of cannabis is of particular concern.

Disrupted Circadian Rhythm as a Common Player in Developmental Models of Neuropsychiatric Disorders.

The environment in which individuals develop and mature is critical for their physiological and psychological outcome; in particular, the intrauterine environment has reached far more clinical relevance given its potential influence on shaping brain function and thus mental health. Gestational stress and/or maternal infection during pregnancy has been related with an increased incidence of neuropsychiatric disorders, including depression and schizophrenia. In this framework, the use of animal models has allowed a formal and deep investigation of causal determinants. Despite disruption of circadian clocks often represents a hallmark of several neuropsychiatric disorders, the relationship between disruption of brain development and the circadian system has been scarcely investigated. Nowadays, there is an increasing amount of studies suggesting a link between circadian system malfunction, early-life insults and the appearance of neuropsychiatric diseases at adulthood. Here, we briefly review evidence from clinical literature and animal models suggesting that the exposure to prenatal insults, i.e. severe gestational stress or maternal immune activation, changes the foetal hormonal milieu increasing the circulating levels of both glucocorticoids and pro-inflammatory cytokines. These two biological events have been reported to affect genes expression in experimental models and critically interfere with brain development triggering and/or exacerbating behavioural anomalies in the offspring. Herein, we highlight the importance to unravel the individual components of the body circadian system that might also be altered by prenatal insults and that may be causally associated with the disruption of neural and endocrine developmental programming.

Behavioral, endocrine and immunological characteristics of a murine model of premature aging.

We have previously shown that differences in life span among members of Swiss mouse populations appear to be related to their exploration of a T-maze, with a slow exploration ('slow mice') being linked to alteration of spontaneous behavior and monoaminergic systems, impaired immune function and shorter life span. In general these traits resemble some of the characteristics of chronologically old animals. Thus, we proposed the 'slow mice' as a model of prematurely aging mice (PAM). Now, we have compared female PAM with non-prematurely aging mice (NPAM) as regards a number of behavioral, endocrine and immunological parameters which were studied under both basal and stress conditions. In the present study the animals were chronologically younger than those used in our previous work. When compared to NPAM, the PAM showed increased anxiogenic-like responses in the plus-maze, increased basal corticosterone levels and decreased corticosterone responses to stress. The PAM also showed a decreased natural killer activity as well as decreased lymphoproliferative responses to mitogens. Moreover, the mitogen-induced lymphoproliferative responses of the PAM appeared to be more susceptible to stress. The data indicate that certain characteristics of the PAM are already present in animals of very young chronological age and provide new information for a more complete characterization of the PAM from a neuroimmunoendocrine viewpoint.