Cannabidiol and positive effects on object recognition memory in an in vivo model of Fragile X Syndrome: Obligatory role of hippocampal GPR55 receptors.

Cannabidiol (CBD), a non-psychotomimetic constituent of Cannabis sativa, has been recently approved for epileptic syndromes often associated with Autism spectrum disorder (ASD). However, the putative efficacy and mechanism of action of CBD in patients suffering from ASD and related comorbidities remain debated, especially because of the complex pharmacology of CBD. We used pharmacological, immunohistochemical and biochemical approaches to investigate the effects and mechanisms of action of CBD in the recently validated Fmr1-Δexon 8 rat model of ASD, that is also a model of Fragile X Syndrome (FXS), the leading monogenic cause of autism. CBD rescued the cognitive deficits displayed by juvenile Fmr1-Δexon 8 animals, without inducing tolerance after repeated administration. Blockade of CA1 hippocampal GPR55 receptors prevented the beneficial effect of both CBD and the fatty acid amide hydrolase (FAAH) inhibitor URB597 in the short-term recognition memory deficits displayed by Fmr1-Δexon 8 rats. Thus, CBD may exert its beneficial effects through CA1 hippocampal GPR55 receptors. Docking analysis further confirmed that the mechanism of action of CBD might involve competition for brain fatty acid binding proteins (FABPs) that deliver anandamide and related bioactive lipids to their catabolic enzyme FAAH. These findings demonstrate that CBD reduced cognitive deficits in a rat model of FXS and provide initial mechanistic insights into its therapeutic potential in neurodevelopmental disorders.

Differential diagnosis of myopic choroidal neovascularization (mCNV): insights from multimodal imaging and treatment implications.

PURPOSE: The aim of this article is to conduct a comprehensive systematic review about the current understandings and differential diagnosis of myopic choroidal neovascularization (mCNV) and other several similar diseases, describing their multimodal imaging analysis, prognostic implications, and current types of management. METHODS: This systematic review was performed based on a search on the PubMed database of relevant papers regarding mCNV and other entities discussed in the paper, according to our current knowledge. RESULTS: Through the integration of a multimodal imaging approach, especially optical coherence tomography (OCT), along with accurate demographic and clinical assessment, it becomes possible to effectively differentiate mCNV from similar yet heterogeneous entities. These conditions include macular hemorrhage due to new lacquer crack (LC) formation, inflammatory diseases such as punctate inner choroidopathy (PIC)/multifocal choroidits (MFC) and epiphenomenon multiple evanescent white dot syndrome (Epi-MEWDS), neovascular age-related macular degeneration (nAMD), idiopathic CNV (ICNV), dome-shaped macula (DSM) with subretinal fluid, retinal pigment epithelium (RPE) humps, angioid streaks (AS), choroidal rupture (CR), and choroidal osteoma (CO). Each one of these entities will be described and discussed in this article. CONCLUSION: Myopic choroidal neovascularization is a common retinal condition, especially among young individuals. Accurate diagnosis and differentiation from similar conditions are crucial for effective treatment. Multimodal imaging, particularly OCT, plays a crucial role in precise assessment. Future research should focus on defining biomarkers and distinguishing features to facilitate prompt treatment.

Subretinal hyperreflective material in retinal and chorioretinal disorders: A comprehensive review.

Subretinal hyperreflective material (SHRM) is a common and remarkable optical coherence tomography (OCT) biomarker whose importance is emerging in several retinal and chorioretinal diseases, including age-related macular degeneration, central serous chorioretinopathy, polypoidal choroidal vasculopathy, pathologic myopia, posterior uveitis, vitelliform lesions and macular dystrophies, and rarer disorders. Multimodal imaging, also thanks to the introduction of OCT angiography, allowed a deeper characterisation of SHRM components and its morphological changes after treatment, suggesting its usefulness in clinical practice. We discuss and summarize the nature, multimodal imaging characteristics, and prognostic and predictive significance of SHRM in the different retinal and choroidal disorders in which it has been described.

Group I and group II metabotropic glutamate receptors are upregulated in the synapses of infant rats prenatally exposed to valproic acid.

RATIONALE: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and restricted/stereotyped behavior. Prenatal exposure to valproic acid (VPA) is associated with an increased risk of developing ASD in humans and autistic-like behaviors in rodents. Increasing evidence indicates that dysfunctions of glutamate receptors at synapses are associated with ASD. In the VPA rat model, an involvement of glutamate receptors in autism-like phenotypes has been suggested; however, few studies were carried out on metabotropic glutamate (mGlu) receptors. OBJECTIVES: We examined the protein expression levels of group I (mGlu1 and mGlu5) and group II (mGlu2/3) mGlu receptors in rats prenatally exposed to VPA and evaluated the effect of mGlu receptor modulation on an early autism-like phenotype in these animals. METHODS: We used western blotting analysis on synaptosomes obtained from forebrain of control and VPA rats at different ages (postnatal day P13, 35, 90) and carried out ultrasonic vocalization (USV) emission test in infant control and VPA rats. RESULTS: The expression levels of all these receptors were significantly increased in infant VPA rats. No changes were detected in adolescent and adult rats. An acute treatment with the preferential mGlu2/3 antagonist, LY341495, attenuated the impairment in the USV emission in VPA rats. No effect was observed after a treatment with the mGlu5 selective antagonist, MTEP. CONCLUSIONS: Our findings demonstrate that the expression of group I and group II mGlu receptors is upregulated at synapses of infant VPA rats and suggest that mGlu2/3 receptor modulation may have a therapeutic potential in ASD.

Imaging biomarkers and clinical factors associated with the rate of progressive inner and outer retinal thinning in patients with diabetic macular edema.

The aim of this study was to assess the relationship of clinical characteristics to the rate of retinal thinning in eyes with diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (VEGF) therapy. We analyzed subjects with a long-term follow-up (≥ 3 years) and evidence of resolved DME after the initiation of anti-VEGF therapy (baseline visit). To measure the long-term rate of retinal thinning during treatment, a second visit (first visit with evidence of resolved DME after 3 years) was also considered. A longitudinal quantitative topographical assessment of the inner and outer retinal thicknesses was provided. Clinical characteristics were associated with the rate of longitudinal retinal thinning. We included 56 eyes (50 patients) in the analysis. A significant longitudinal thinning in the inner and outer retina was detected in all the analyzed regions (p values between 0.027 and < 0.0001). In the multivariable analysis, type of diabetes (type 2 vs. type 1) was associated with increased foveal inner retinal thinning (p = 0.019). A higher number of subfoveal neuroretinal detachment during follow-up (p = 0.006) was associated with faster rates of foveal outer retinal thinning. Type of diabetes (p < 0.0001), higher age (p = 0.033) and cystoid macular edema phenotype (p = 0.040) were associated with increased parafoveal inner retinal thinning. Gender (p = 0.003) and diabetic retinopathy stage (p = 0.013) were associated with faster rates of perifoveal inner retinal thinning, while diabetic retinopathy stage (p = 0.036) was associated with increased perifoveal outer retinal thinning. In conclusion, clinical factors, including DME phenotypes, were associated with the rates of retinal thinning in patients undergoing anti-VEGF treatment.

Anandamide and 2-arachidonoylglycerol differentially modulate autistic-like traits in a genetic model of autism based on FMR1 deletion in rats.

Autism spectrum disorder (ASD) has a multifactorial etiology. Major efforts are underway to understand the neurobiological bases of ASD and to develop efficacious treatment strategies. Recently, the use of cannabinoid compounds in children with neurodevelopmental disorders including ASD has received increasing attention. Beyond anecdotal reports of efficacy, however, there is limited current evidence supporting such an intervention and the clinical studies currently available have intrinsic limitations that make the interpretation of the findings challenging. Furthermore, as the mechanisms underlying the beneficial effects of cannabinoid compounds in neurodevelopmental disorders are still largely unknown, the use of drugs targeting the endocannabinoid system remains controversial. Here, we studied the role of endocannabinoid neurotransmission in the autistic-like traits displayed by the recently validated Fmr1-Δexon 8 rat model of autism. Fmr1-Δexon 8 rats showed reduced anandamide levels in the hippocampus and increased 2-arachidonoylglycerol (2-AG) content in the amygdala. Systemic and intra-hippocampal potentiation of anandamide tone through administration of the anandamide hydrolysis inhibitor URB597 ameliorated the cognitive deficits displayed by Fmr1-Δexon 8 rats along development, as assessed through the novel object and social discrimination tasks. Moreover, blockade of amygdalar 2-AG signaling through intra-amygdala administration of the CB1 receptor antagonist SR141716A prevented the altered sociability displayed by Fmr1-Δexon 8 rats. These findings demonstrate that anandamide and 2-AG differentially modulate specific autistic-like traits in Fmr1-Δexon 8 rats in a brain region-specific manner, suggesting that fine changes in endocannabinoid mechanisms contribute to ASD-related behavioral phenotypes.

Psilocybin mitigates the cognitive deficits observed in a rat model of Fragile X syndrome.

RATIONALE: Fragile X syndrome (FXS) is the most common form of inherited intellectual disability (ID) and the leading monogenic cause of autism spectrum disorder (ASD). Serotonergic neurotransmission has a key role in the modulation of neuronal activity during development, and therefore, it has been hypothesized to be involved in ASD and co-occurring conditions including FXS. As serotonin is involved in synaptic remodeling and maturation, serotonergic insufficiency during childhood may have a compounding effect on brain patterning in neurodevelopmental disorders, manifesting as behavioral and emotional symptoms. Thus, compounds that stimulate serotonergic signaling such as psilocybin may offer promise as effective early interventions for developmental disorders such as ASD and FXS. OBJECTIVES: The aim of the present study was to test whether different protocols of psilocybin administration mitigate cognitive deficits displayed by the recently validated Fmr1-Δexon 8 rat model of ASD, which is also a model of FXS. RESULTS: Our results revealed that systemic and oral administration of psilocybin microdoses normalizes the aberrant cognitive performance displayed by adolescent Fmr1-Δexon 8 rats in the short-term version of the novel object recognition test-a measure of exploratory behavior, perception, and recognition. CONCLUSIONS: These data support the hypothesis that serotonin-modulating drugs such as psilocybin may be useful to ameliorate ASD-related cognitive deficits. Overall, this study provides evidence of the beneficial effects of different schedules of psilocybin treatment in mitigating the short-term cognitive deficit observed in a rat model of FXS.

Camellens FIL622-1 IOL Implantation in the Ciliary Sulcus: Refractive Outcomes and Optimization of A-constant.

PURPOSE: To assess the refractive outcomes of patients who had sulcus implantation of the Camellens FIL622-1 intraocular lens (IOL) (Soleko) after posterior capsular rupture, and to optimize the A-constant suggested by the manufacturer. METHODS: This study included patients who underwent secondary Camellens FIL622-1 IOL implantation in the ciliary sulcus after complicated cataract surgery with posterior capsular rupture. IOL power was calculated by the SRK/T formula, using the recommended A-constant (118.8) for ciliary sulcus implantation. A new optimized A-constant was obtained and used to evaluate the refractive outcomes. The main outcome measures were mean prediction error (PE), median absolute error (MedAE), mean absolute error (MAE), and percentage of eyes with a PE within ±0.50, ±1.00, and ±2.00 diopters (D). RESULTS: Forty patients (40 eyes) were included in the study. The new optimized A-constant was 117.5, and the mean PE, MedAE, and MAE was -0.02 ± 0.73, 0.34, and 0.54, respectively. The percentage of eyes with a PE within ±0.50, ±1.00, and ±2.00 D was 65%, 87.5%, and 100%, respectively. CONCLUSIONS: The Camellens FIL622-1 IOL represents a valid option as sulcus implantation after posterior capsular rupture and it would guarantee the surgeon an on-label option with a more accurate biometric calculation, at the time of surgical implantation, with the new optimized A-constant. [J Refract Surg. 2022;38(12):806-811.].