G Protein-Coupled Estrogen Receptor Immunoreactivity in the Rat Hypothalamus Is Widely Distributed in Neurons, Astrocytes, and Oligodendrocytes, Fluctuates during the Estrous Cycle, and Is Sexually Dimorphic.

INTRODUCTION: The membrane-associated G protein-coupled estrogen receptor 1 (GPER) mediates the regulation by estradiol of arginine-vasopressin immunoreactivity in the supraoptic and paraventricular hypothalamic nuclei of female rats and is involved in the estrogenic control of hypothalamic regulated functions, such as food intake, sexual receptivity, and lordosis behavior. OBJECTIVE: To assess GPER distribution in the rat hypothalamus. METHODS: GPER immunoreactivity was assessed in different anatomical subdivisions of five selected hypothalamic regions of young adult male and cycling female rats: the arcuate nucleus, the lateral hypothalamus, the paraventricular nucleus, the supraoptic nucleus, and the ventromedial hypothalamic nucleus. GPER immunoreactivity was colocalized with NeuN as a marker of mature neurons, GFAP as a marker of astrocytes, and CC1 as a marker of mature oligodendrocytes. RESULTS: GPER immunoreactivity was detected in hypothalamic neurons, astrocytes, and oligodendrocytes. Sex and regional differences and changes during the estrous cycle were detected in the total number of GPER-immunoreactive cells and in the proportion of neurons, astrocytes, and oligodendrocytes that were GPER-immunoreactive. CONCLUSIONS: These findings suggest that estrogenic regulation of hypothalamic function through GPER may be different in males and females and may fluctuate during the estrous cycle in females.

Early maternal deprivation immunologically primes hippocampal synapses by redistributing interleukin-1 receptor type I in a sex dependent manner.

Challenges experienced in early life cause an enduring phenotypical shift of immune cells towards a sensitised state that may lead to an exacerbated reaction later in life and contribute to increased vulnerability to neurological diseases. Peripheral and central inflammation may affect neuronal function through cytokines such as IL-1. The extent to which an early life challenge induces long-term alteration of immune receptors organization in neurons has not been shown. We investigated whether a single episode of maternal deprivation (MD) on post-natal day (PND) 9 affects: (i) the synapse distribution of IL-1RI together with subunits of NMDA and AMPA receptors; and (ii) the interactions between IL-1RI and the GluN2B subunit of the NMDAR in the long-term, at PND 45. MD increased IL-1RI levels and IL-1RI interactions with GluN2B at the synapse of male hippocampal neurons, without affecting the total number of IL-1RI or NMDAR subunits. Although GluN2B and GluN2A were slightly but not significantly changed at the synapse, their ratio was significantly decreased in the hippocampus of the male rats who had experienced MD; the levels of the GluA1 and GluA2 subunits of the AMPAR were also decreased. These changes were not observed immediately after the MD episode. None of the observed alterations occurred in the hippocampus of the females or in the prefrontal cortex of either sex. These data reveal a long-term, sex-dependent modification in receptor organisation at the hippocampal post-synapses following MD. We suggest that this effect might contribute to priming hippocampal synapses to the action of IL-1ß.

Correlation between clinical findings and magnetic resonance imaging for the assessment of local response after standard treatment in cervical cancer.

BACKGROUND: The aim of our study is to evaluate the correlation between gynecological examination and magnetic resonance (MRI) findings for the assessment of local response in cervical cancer patients treated with radiotherapy/chemotherapy (RT/ChT). PATIENTS AND METHODS: This study is a retrospective review of 75 consecutive cervical cancer patients from April 2004 to November 2009 treated with RT/ChT. Clinical and radiological data were subsequently analyzed. Patient's median age was 51 with a FIGO stage from Ib to IVb. Individualized RT/ChT was administered with a median dose of 45 Gy. Sixty-three patients received a complementary brachytherapy. Seventy-one patients received chemotherapy on a weekly basis. Gynecological exam was performed 3 months and 6 months after treatment and these findings were compared to MRI results at the same time. STATISTIC ANALYSIS: We used the Spearman's Rho test to determine the correlation level between the clinical and radiological methods. RESULTS: A correlation of 0.68 (60%) was observed between the clinical and MRI findings at 3 months with a further increase of up to 0.86 (82.6%) at 6 months. In the few cases with a poor correlation, the subsequent assessment and the natural history of the disease showed a greater value of the clinical exam as compared with the MRI findings. CONCLUSIONS: Physical exam remains an essential tool to evaluate the local response to RT/ChT for cervical cancer. The optimal clinical radiological correlation found at 6 months after treatment suggests that the combination of gynecological examination and MRI are probably adequate in patient monitoring.

"Shikonin inhibits microglia activation and reduces CFA-induced mechanical hyperalgesia in an animal model of pain".

Shikonin is an ointment produced from Lithospermun erythrorhizon which has been used in traditional medicine both in Europe and Asia for wound healing and is associated with anti-inflammatory properties. The goal of this work is to assess the analgesic properties of Shikonin in the CFA-induced inflammation model of pain. Rats were subjected to inflammation of the hind paw by CFA injection with a preventive injection of Shikonin and compared to either a control group or to a CFA-inflamed group with the vehicle drug solution. Inflammation of the hind paw by CFA was assessed by measurement of the dorsal to plantar diameter. Mechanical thresholds were established by means of the Von Frey filaments which are calibrated filaments that exert a defined force. Finally, the spinal cord of the studied animals was extracted to analyse the microglia population through immunohistochemistry using the specific marker Iba-1. Our results show that Shikonin reduces the paw oedema caused by CFA inflammation. Subsequently, there is a concomitant restoration of the mechanical thresholds reduced by CFA hind paw injection. Additionally, spinal microglia is activated after CFA-induced inflammation. Our results show that microglia is inhibited by Shikonin and has concomitant restoration of the mechanical thresholds. Our findings demonstrate for the first time that Shikonin inhibits microglia morphological changes and thereby ameliorates pain-like behaviour elicited by mechanical stimulation.

Levels of Evidence for Radiation Therapy Recommendations in the National Comprehensive Cancer Network (NCCN) Clinical Guidelines.

PURPOSE: The National Comprehensive Cancer Network (NCCN) clinical guidelines influence medical practice, payor coverage, and standards of care. The levels of evidence underlying radiation therapy recommendations in NCCN have not been systematically explored. Herein, we aim to systematically investigate the NCCN recommendations pertaining to the categories of consensus and evidence (CE) for radiation therapy. METHODS AND MATERIALS: We evaluated the distribution of CE underlying current treatment recommendations for the 20 most prevalent cancers in the United States with at least 10 radiation therapy recommendations in the NCCN clinical guidelines. For context, the distribution of evidence in the radiation therapy guidelines was compared with that of systemic therapy using a χ2 test. The proportion of category I CE between radiation and systemic therapy was compared using a 2-proportion, 2-tailed z-test in total and for each disease site. A P value of < .05 was considered significant. RESULTS: Among all radiation therapy recommendations, the proportions of category I, IIA, IIB, and III CE were 9.7%, 80.6%, 8.4%, and 1.3%, respectively. When analyzed by disease site, cervix and breast cancer had the highest portion of category I CE (33% and 31%, respectively). There was no radiation therapy category I CE for hepatobiliary, bone, pancreatic, melanoma, and uterine cancers. There was a significant difference in the distribution of CE between the systemic therapy recommendations and the radiation therapy recommendations (χ2 statistic 64.16, P < .001). Overall, there was a significantly higher proportion of category I CE in the systemic therapy recommendations compared with the radiation therapy recommendations (12.3% vs 9.7%, P = .043). CONCLUSIONS: Only 9.7% of radiation therapy recommendations in NCCN guidelines are category I CE. The highest levels of evidence for radiation therapy are in breast and cervical cancers. Despite major advances in the field, these data underline that the majority of NCCN radiation therapy recommendations are based on uniform expert opinion and not on higher level evidence.

Converging action of alcohol consumption and cannabinoid receptor activation on adult hippocampal neurogenesis.

Alcoholism is characterized by successive periods of abstinence and relapse, resulting from long-lasting changes in various circuits of the central nervous system. Accumulating evidence points to the endocannabinoid system as one of the most relevant biochemical systems mediating alcohol addiction. The endocannabinoid system regulates adult neurogenesis, a form of long-lasting adult plasticity that occurs in a few areas of the brain, including the dentate gyrus. Because exposure to psychotropic drugs regulates adult neurogenesis, it is possible that neurogenesis might be implicated in the pathophysiology, and hence treatment, of neurobiological illnesses related to drugs of abuse. Here, we investigated the sensitivity of adult hippocampal neurogenesis to alcohol and the cannabinoid receptor agonist WIN 55,212-2 (WIN). Specifically, we analysed the potential link between alcohol relapse, cannabinoid receptor activation, and adult neurogenesis. Adult rats were exposed to subchronic alcohol binge intoxication and received the cannabinoid receptor agonist WIN. Another group of rats were subjected to an alcohol operant self-administration task. Half of these latter animals had continuous access to alcohol, while the other half were subjected to alcohol deprivation, with or without WIN administration. WIN treatment, when administered during alcohol deprivation, resulted in the greatest increase in alcohol consumption during relapse. Together, forced alcohol binge intoxication and WIN administration dramatically reduced hippocampal neurogenesis. Furthermore, adult neurogenesis inversely correlated with voluntary consumption of alcohol. These findings suggest that adult hippocampal neurogenesis is a key factor involved in drug abuse and that it may provide a new strategy for the treatment of alcohol addiction and dependence.

Maternal deprivation has sexually dimorphic long-term effects on hypothalamic cell-turnover, body weight and circulating hormone levels.

Maternal deprivation (MD) has numerous outcomes, including modulation of neuroendocrine functions. We previously reported that circulating leptin levels are reduced and hypothalamic cell-turnover is affected during MD, with some of these effects being sexually dimorphic. As leptin modulates the development of hypothalamic circuits involved in metabolic control, we asked whether MD has long-term consequences on body weight, leptin levels and the expression of neuropeptides involved in metabolism. Rats were separated from their mother for 24h starting on postnatal day (PND) 9 and sacrificed at PNDs 13, 35 and 75. In both sexes MD reduced body weight, but only until puberty, while leptin levels were unchanged at PND 35 and significantly reduced at PND 75. Adiponectin levels were also reduced at PND 75 in females, while testosterone levels were reduced in males. At PND 13, MD modulated cell-turnover markers in the hypothalamus of males, but not females and increased nestin, a marker of immature neurons, in both sexes, with males having higher levels than females and a significantly greater rise in response to MD. There was no effect of MD on hypothalamic mRNA levels of the leptin receptor or metabolic neuropeptides or the mRNA levels of leptin and adiponectin in adipose tissue. Thus, MD has long-term effects on the levels of circulating hormones that are not correlated with changes in body weight. Furthermore, these endocrine outcomes are different between males and females, which could be due to the fact that MD may have sexually dimorphic effects on hypothalamic development.

Impact of quantization algorithm and number of gray level intensities on variability and repeatability of low field strength magnetic resonance image-based radiomics texture features.

PURPOSE: The purpose of this work was to investigate the impact of quantization preprocessing parameter selection on variability and repeatability of texture features derived from low field strength magnetic resonance (MR) images. METHODS: Texture features were extracted from low field strength images of a daily image QA phantom with four texture inserts. Feature variability over time was quantified using all combinations of three quantization algorithms and four different numbers of gray level intensities. In addition, texture features were extracted using the same combinations from the low field strength MR images of the gross tumor volume (GTV) and left kidney of patients with repeated set up scans. The impact of region of interest (ROI) preprocessing on repeatability was investigated with a test-retest study design. RESULTS: The phantom ROIs quantized to 64 Gy level intensities using the histogram equalization method resulted in the greatest number of features with the least variability. There was no clear method that resulted in the highest repeatability in the GTV or left kidney. However, eight texture features extracted from the GTV were repeatable regardless of ROI processing combination. CONCLUSION: Low field strength MR images can provide a stable basis for texture analysis with ROIs quantized to 64 Gy levels using histogram equalization, but there is no clear optimal combination for repeatability.

Advantages of Radiation Therapy Simulation with 0.35 Tesla Magnetic Resonance Imaging for Stereotactic Ablation of Spinal Metastases.

The hybrid 0.35T magnetic resonance imaging (MRI) and radiation therapy system functions in part as a simulation platform for treatment planning. We have found that the images generated are particularly helpful for planning of stereotactic radiation therapy for spinal metastases. Advantages include the following: (1) Low-field MRI mitigates magnetic susceptibility artifacts caused by spinal hardware. (2) Volumetric pulse sequence provides isotropic images for improved target delineation. (3) Wide-bore MRI in the radiation oncology department allows for easy simulation in treatment position for accurate fusion across imaging modalities. (4) When patients are treated on the MRI and radiation therapy hybrid device, adaptive radiation therapy is available for special situations to avoid mobile organs at risk.

G Protein-Coupled Estrogen Receptor Immunoreactivity Fluctuates During the Estrous Cycle and Show Sex Differences in the Amygdala and Dorsal Hippocampus.

G protein-coupled estrogen receptor (GPER) in the amygdala and the dorsal hippocampus mediates actions of estradiol on anxiety, social recognition and spatial memory. In addition, GPER participates in the estrogenic regulation of synaptic function in the amygdala and in the process of adult neurogenesis in the dentate gyrus. While the distribution of the canonical estrogen receptors α and ß in the amygdala and dorsal hippocampus are well characterized, little is known about the regional distribution of GPER in these brain regions and whether this distribution is affected by sex or the stages of the estrous cycle. In this study we performed a morphometric analysis of GPER immunoreactivity in the posterodorsal medial, anteroventral medial, basolateral, basomedial and central subdivisions of the amygdala and in all the histological layers of CA1 and the dentate gyrus of the dorsal hippocampal formation. The number of GPER immunoreactive cells was estimated in these different structures. GPER immunoreactivity was detected in all the assessed subdivisions of the amygdaloid nucleus and dorsal hippocampal formation. The number of GPER immunoreactive cells was higher in males than in estrus females in the central (P = 0.001) and the posterodorsal medial amygdala (P < 0.05); higher in males than in diestrus females in the strata orients (P < 0.01) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer of the dentate gyrus (P < 0.01); higher in diestrus females than in males in the basolateral amygdala (P < 0.05); higher in diestrus females than in estrus females in the central (P < 0.01), posterodorsal medial (P < 0.01) and basolateral amygdala (P < 0.01) and higher in estrus females than in diestrus females in the strata oriens (P < 0.05) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer (P < 0.05) and the hilus of the dentate gyrus (P < 0.05). The findings suggest that estrogenic regulation of the amygdala and hippocampus through GPER may be different in males and in females and may fluctuate during the estrous cycle.

MRI-guided stereotactic ablative radiation therapy of spinal bone metastases: a preliminary experience.

OBJECTIVE: MRI provides clear visualization of spinal cord, tumor, and bone for patient positioning and verification during MRI-guided radiotherapy (MRI-RT). Therefore, we wished to evaluate spine stereotactic ablative radiotherapy (SABR) feasibility with MRI-RT. Given dosimetric limitations of first generation Co-60 MRI-RT, we then evaluated improvements by newer linear accelerator (linac) MRI-RT. METHODS: Nine spinal metastases were treated with Co-60 MRI-RT. Seven received a single 16 Gy fraction, and two received three fractions totaling 24 or 30 Gy. After replanning with linac MRI-RT software, comparisons of organ at risk and dose spillage objectives between Co-60 and linac plans were performed. RESULTS: Spinal cord and cauda equina dose constraints were met in all Co-60 cases. Treatments were delivered successfully with real-time imaging during treatment and no treatment-related toxicities. While limits for dose spillage into surrounding soft tissues were not achieved due to the limitations of the Co-60 system, this could be corrected with linac MRI-RT delivery. CONCLUSIONS: MRI-RT SABR of spinal metastases is feasible with Co-60 MRI-RT. Dose delivery is improved by linac MRI-RT. ADVANCES IN KNOWLEDGE: This is the first report of MRI-RT for SABR of spinal metastases. The enhanced visualization of anatomy by MRI may facilitate RT dose escalation for spine SABR.

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.

Early maternal deprivation induces gender-dependent changes on the expression of hippocampal CB(1) and CB(2) cannabinoid receptors of neonatal rats.

Early maternal deprivation (MD) in rats (24 h, postnatal day 9-10) is a model for neurodevelopmental stress. There are some data proving that MD affects the endocannabinoid system (ECS) in a gender-dependent manner, and that these changes may account for the proposed schizophrenia-like phenotype of MD rats. The impact of MD on cannabinoid receptor distribution in the hippocampus is unknown. The aim of this study is to evaluate the expression of CB(1) and CB(2) receptors in diverse relevant subregions (DG, CA1, and CA3) of the hippocampus in 13-day-old rats by immunohistochemistry and densitometry. MD induced a significant decrease in CB(1) immunoreactivity (more marked in males than in females), which was mainly associated with fibers in the strata pyramidale and radiatum of CA1 and in the strata oriens, pyramidale, and radiatum of CA3. In contrast, MD males and females showed a significant increase in CB(2) immunoreactivity in the three hippocampal areas analyzed that was detected in neuropil and puncta in the stratum oriens of CA1 and CA3, and in the polymorphic cell layer of the dentate gyrus. A marked sex dimorphism was observed in CA3, with females exhibiting higher CB(1) immunoreactivity than males, and in dentate gyrus, with females exhibiting lower CB(2) immunoreactivity than males. These results point to a clear association between developmental stress and dysregulation of the ECS. The present MD procedure may provide an interesting experimental model to further address the role of the ECS in neurodevelopmental mental illnesses such as schizophrenia.

Effects of adolescent nicotine and SR 147778 (Surinabant) administration on food intake, somatic growth and metabolic parameters in rats.

Tobacco smoking and obesity are worldwide important health problems with a growing impact in adolescent and young adults. One of the consequences of nicotine withdrawal is an increase in body weight that can act as a risk factor to relapse. Experimental therapies with a cannabinoid receptor antagonist have been recently proposed for both cigarette smoking and complicated overweight. In the present study, we aimed to investigate metabolic and hormonal effects of chronic nicotine treatment (during treatment and in abstinence) in an animal model of adolescence as well as to address the pharmacological effects of the novel selective CB1 cannabinoid receptor antagonist, SR 147778 (Surinabant). Adolescence (postnatal days 37-44) and/or post-adolescence (postnatal days 45-59) administration of Surinabant reduced body weight gain, as well as plasma glucose levels and triglycerides. The drug also reduced insulin and leptin secretion, and increased adiponectin and corticosterone levels. The effects showed sexual dimorphisms and, in general, were more pronounced in females. Chronic exposure to nicotine (0.8 mg/kg), from postnatal days 30-44 did not result in overt effects on food intake or body weight gain. However, it altered certain responses to the administration of Surinabant, both when the two drugs were given simultaneously and when Surinabant was administered during the post-adolescence period, along nicotine withdrawal. The present results indicate that the endogenous cannabinoid system is active as a metabolic modulator during adolescence and that nicotine exposure can induce long-lasting effects on metabolic regulation, altering cannabinoid modulation of energy expenditure and metabolism.

Feasibility of Adaptive MR-guided Stereotactic Body Radiotherapy (SBRT) of Lung Tumors.

Online adaptive radiotherapy (ART) with frequent imaging has the potential to improve dosimetric accuracy by accounting for anatomical and functional changes during the course of radiotherapy. Presented are three interesting cases that provide an assessment of online adaptive magnetic resonance-guided radiotherapy (MRgRT) for lung stereotactic body radiotherapy (SBRT). The study includes three lung SBRT cases, treated on an MRgRT system where MR images were acquired for planning and prior to each treatment fraction. Prescription dose ranged from 48 to 50 Gy in four to five fractions, normalized to where 95% of the planning target volume (PTV) was covered by 100% of the prescription dose. The process begins with the gross tumor volume (GTV), PTV, spinal cord, lungs, heart, and esophagus being delineated on the planning MRI. The treatment plan was then generated using a step-and-shoot intensity modulated radiotherapy (IMRT) technique, which utilized a Monte Carlo dose calculation. Next, the target and organs at risk (OAR) contours from the planning MRI were deformably propagated to the daily setup MRIs. These deformed contours were reviewed and modified by the physician. To determine the efficacy of ART, two different strategies were explored: 1) Calculating the plan created for the planning MR on each fraction setup MR dataset (Non-Adapt) and 2) creating a new optimized IMRT plan on the fraction setup MR dataset (FxAdapt). The treatment plans from both strategies were compared using the clinical dose-volume constraints. PTV coverage constraints were not met for 33% Non-Adapt fractions; all FxAdapt fractions met this constraint. Eighty-eight percent of all OAR constraints studied were better on FxAdapt plans, while 12% of OAR constraints were superior on Non-Adapt fractions. The OAR that garnered the largest benefit would be the uninvolved lung, with superior sparing in 92% of the FxAdapt studied. Similar, but less pronounced, benefits from adaptive planning were experienced for the spinal cord, chest wall, and esophagus. Online adaptive MR-guided lung SBRT can provide better target conformality and homogeneity and OAR sparing compared with non-adaptive SBRT in selected cases. Conversely, if the PTV isn't adjacent to multiple OARs, then the benefit from ART may be limited. Further studies, which incorporate a larger cohort of patients with uniform prescriptions, are needed to thoroughly evaluate the benefits of daily online ART during MRgRT.

Magnetic Resonance-guided External Beam Radiation and Brachytherapy for a Patient with Intact Cervical Cancer.

Radiation treatment verification has improved significantly over the past decades. The field has moved from film X-rays and skin marks to fiducial tracking and daily cone beam computed tomography (CBCT) for tumor localization. We now have the ability to perform daily on-board magnetic resonance imaging (MRI), which provides superior soft tissue contrast compared to computed tomography (CT). In the management of cervical cancer, the brachytherapy literature has demonstrated that MRI allows for better delineation of the high-risk clinical target volume (HR-CTV) and the use of MRI-guided brachytherapy has translated into improved treatment outcomes. Consensus contouring guidelines for intensity modulated radiation therapy (IMRT) for cervical cancer advise including the whole uterus in the target volume and adding large planning target volume (PTV) margins to account for inter-fractional uterine motion and target motion resulting from variable rectal and bladder filling. MRI-guided radiation therapy (MRgRT) systems enable the possibility to precisely delineate the target volume on a daily basis and to perform truly adaptive delivery. This advancement in technology provides the opportunity to explore how external beam treatment volumes could be safely reduced for better sparing of pelvic organs for the benefit of our patients with cervical cancer. We describe the MR-guided definitive external beam radiation therapy and brachytherapy for a 32-year-old woman with intact cervical cancer. We contoured the uterus, bladder, rectum, and gross tumor volume (GTV) on each of her 25 set-up MRIs. We demonstrate a steady reduction in the GTV and increased displacement of the uterus and GTV as the GTV decreased in size. The findings presented suggest that cervical cancer could greatly benefit from an adaptive MRgRT approach.

Early maternal deprivation and neonatal single administration with a cannabinoid agonist induce long-term sex-dependent psychoimmunoendocrine effects in adolescent rats.

Maternal deprivation [24h on postnatal day 9] might represent an animal model of schizophrenia and behavioural and neurochemical alterations observed in adulthood may be mediated by hippocampal impairments induced by abnormally increased glucocorticoids due to neonatal stress. We aimed to provide new data for psychoimmunoendocrine characterization of this animal model by evaluating its effects in adolescent rats of both genders. In previous studies we found that cannabinoid compounds counteracted the enhanced impulsivity of maternally deprived animals and that the cannabinoid receptor agonist WIN 55,212-2 showed neuroprotective properties in neonatal rats. So, we hypothesised that this compound could counteract at least some of the detrimental effects that we expected to find in maternally deprived animals. Accordingly, the drug was administered immediately after the maternal deprivation period. Maternally deprived males showed significantly decreased motor activity in the holeboard and the plus-maze. The cannabinoid agonist induced, exclusively in males, a significant anxiogenic-like effect, which was reversed by maternal deprivation. In the forced swimming test, both treatments independently induced depressive-like responses. Maternal deprivation reduced immunological function whereas the drug exerted tissue-dependent effects on the immune parameters analysed. Maternally deprived females showed reduced corticosterone levels whereas the cannabinoid agonist increased hormone concentration in all groups. In general, the results show detrimental effects of both treatments as well as intriguing interactions, notably in relation to emotional behaviour and certain immunological responses.

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.

Endocannabinoid system and synaptic plasticity: implications for emotional responses.

The endocannabinoid system has been involved in the regulation of anxiety, and proposed as an inhibitory modulator of neuronal, behavioral and adrenocortical responses to stressful stimuli. Brain regions such as the amygdala, hippocampus and cortex, which are directly involved in the regulation of emotional behavior, contain high densities of cannabinoid CB1 receptors. Mutant mice lacking CB1 receptors show anxiogenic and depressive-like behaviors as well as an altered hypothalamus pituitary adrenal axis activity, whereas enhancement of endocannabinoid signaling produces anxiolytic and antidepressant-like effects. Genetic and pharmacological approaches also support an involvement of endocannabinoids in extinction of aversive memories. Thus, the endocannabinoid system appears to play a pivotal role in the regulation of emotional states. Endocannabinoids have emerged as mediators of short- and long-term synaptic plasticity in diverse brain structures. Despite the fact that most of the studies on this field have been performed using in vitro models, endocannabinoid-mediated plasticity might be considered as a plausible candidate underlying some of the diverse physiological functions of the endogenous cannabinoid system, including developmental, affective and cognitive processes. In this paper, we will focus on the functional relevance of endocannabinoid-mediated plasticity within the framework of emotional responses. Alterations of the endocannabinoid system may constitute an important factor in the aetiology of certain neuropsychiatric disorders, and, in turn, enhancers of endocannabinoid signaling could represent a potential therapeutical tool in the treatment of both anxiety and depressive symptoms.

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.