Search Results (265)

Cannabinoids can bind to several cannabinoid receptors and modulate cellular signaling and gene expression relevant to inflammation and lipid homeostasis. Likewise, several vitamin E analogs can modulate inflammatory signaling and foam cell formation in macrophages by antioxidant and non-antioxidant mechanisms. We analyzed the regulatory effects on the expression of genes involved in cellular lipid homeostasis (e.g., CD36/FAT cluster of differentiation/fatty acid transporter and scavenger receptor SR-B1) and inflammation (e.g., inflammatory cytokines, TNFα, IL1β) by cannabinoids (cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC)) in human THP-1 macrophages with/without co-treatment with natural alpha-tocopherol (RRR-αT), natural RRR-αTA (αTAn), and synthetic racemic all-rac-αTA (αTAr). In general, αTAr inhibited both lipid accumulation and the inflammatory response (TNFα, IL6, IL1β) more efficiently compared to αTAn. Our results suggest that induction of CD36/FAT mRNA expression after treatment with THC can be prevented, albeit incompletely, by αTA (either αTAn or αTAr) or CBD. A similar response pattern was observed with genes involved in lipid efflux (ABCA1, less with SR-B1), suggesting an imbalance between uptake, metabolism, and efflux of lipids/αTA, increasing macrophage foam cell formation. THC increased reactive oxygen species (ROS), and co-treatment with αTAn or αTAr only partially prevented this. To study the mechanisms by which inflammatory and lipid-related genes are modulated, HEK293 cells overexpressing cannabinoid receptors (CB1 or TRPV-1) were transfected with luciferase reporter plasmids containing the human CD36 promoter or response elements for transcription factors involved in its regulation (e.g., LXR and NFκB). In cells overexpressing CB1, we observed activation of NFκB by THC that was inhibited by αTAr. Full article

Hepatocellular carcinoma (HCC) is the main type of liver cancer and one of the malignancies with the highest mortality rates worldwide. HCC is associated with diverse etiological factors including alcohol use, viral infections, fatty liver disease, and liver cirrhosis (a major risk factor for HCC). Unfortunately, many patients are diagnosed at advanced stages of the disease and receive palliative treatment only. Therefore, early markers of HCC and novel therapeutic approaches are urgently needed. The endocannabinoid system is involved in various physiological processes such as motor coordination, emotional control, learning and memory, neuronal development, antinociception, and immunological processes. Interestingly, endocannabinoids modulate signaling pathways involved in cell survival, proliferation, apoptosis, autophagy, and immune response. Consistently, several cannabinoids have demonstrated potential antitumor properties in experimental models. The participation of metabotropic and ionotropic cannabinoid receptors in the biological effects of cannabinoids has been extensively described. In addition, cannabinoids interact with other targets, including several ion channels. Notably, several ion channels targeted by cannabinoids are involved in inflammation, proliferation, and apoptosis in liver diseases, including HCC. In this literature review, we describe and discuss both the endocannabinoid system and exogenous phytocannabinoids, such as cannabidiol and Δ⁹-tetrahydrocannabinol, along with their canonical receptors, as well as the cannabidiol-targeted ion channels and their role in liver cancer and its preceding liver diseases. The cannabidiol-ion channel association is an extraordinary opportunity in liver cancer prevention and therapy, with potential implications for several environments that are for the benefit of cancer patients, including sociocultural, public health, and economic systems. Full article

Hexahydrocannabinol (HHC), a hydrogenated derivative of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), is a semi-synthetic cannabinoid marketed as an alternative to Δ⁹-THC. Its hydroxylated metabolite, 8-hydroxyhexahydrocannabinol (8-OH-HHC), exists as four stereoisomers: (6aR,8R,9R,10aR), (6aR,8S,9S,10aR), (6aR,8S,9R,10aR), and (6aR,8R,9S,10aR). However, the lack of reference standards has hindered pharmacokinetic and forensic studies. This work reports the first stereoselective synthesis and structural confirmation of all four 8-OH-HHC stereoisomers. Two strategies were employed: hydroboration–oxidation and epoxidation–reduction. Hydroboration of Δ⁸-THC with BH₃·THF followed by oxidation predominantly produced anti-isomers (6aR,8R,9R,10aR) and (6aR,8S,9S,10aR) in moderate yields, along with small amounts of syn-isomer (6aR,8S,9R,10aR), suggesting an atypical mechanistic pathway. In contrast, syn-isomers (6aR,8S,9R,10aR) and (6aR,8R,9S,10aR) were accessed via epoxidation of Δ⁸-THC acetate using mCPBA and subsequent reduction with NaBH₃CN/BF₃·OEt₂, affording the desired products with moderate selectivity. Absolute configurations were confirmed by nuclear Overhauser effect spectroscopy (NOESY). These methods will facilitate future pharmacokinetic and forensic research and support the development of improved detection strategies. Full article

Personalizing therapy using medical marijuana (MM) is based on understanding the pharmacogenomics (PGx) and drug–drug interactions (DDIs) involved, as well as identifying potential epigenetic risk markers. In this work, the evidence regarding the role of variants in phase I (CYP2C9, CYP2C19, CYP3A4/5) and II (UGT1A9/UGT2B7) genes, transporters (ABCB1), and selected neurobiological factors (AKT1/COMT) in differentiating responses to Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD) has been reviewed. Data indicating enzyme inhibition by CBD and the possibility of phenoconversion were also considered, which highlights the importance of a dynamic interpretation of PGx in the context of current pharmacotherapy. Simultaneously, the results of epigenetic studies (DNA methylation, histone modifications, and ncRNA) in various tissues and developmental windows were summarized, including the reversibility of some signatures in sperm after a period of abstinence and the persistence of imprints in blood. Based on this, practical frameworks for personalization are proposed: the integration of PGx testing, DDI monitoring, and phenotype correction into clinical decision support systems (CDS), supplemented by cautious dose titration and safety monitoring. The culmination is a proposal of tables and diagrams that organize the most important PGx–DDI–epigenetics relationships and facilitate the elimination of content repetition in the text. The paper identifies areas of implementation maturity (e.g., CYP2C9/THC, CBD-CYP2C19/clobazam, AKT1, and acute psychotomimetic effects) and those requiring replication (e.g., multigenic analgesic signals), indicating directions for future research. Full article

Preclinical data suggest that cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) modulate inflammatory pathways (e.g., NLRP3, NF-κB, and PPAR-γ), but clinical translation into consistent changes in circulating biomarkers remains ambiguous. Two reviewers independently screened the studies, extracted data, and assessed risk of bias with RoB-2. Random-effects meta-analyses (RevMan 5.4.1) formed standardized mean differences (SMD) or mean differences (MD) as appropriate. The certainty of evidence was graded by means of GRADE. Thirteen studies satisfied inclusion criteria; meta-analyses were feasible for IL-6 (four studies, n ≈ 129 per arm), IL-8 (two studies, n ≈ 78 per arm), IL-10 (two studies, n ≈ 92 per arm), and TNF-α (three studies, n ≈ 105 per arm). Pooled estimates favored CBD but were trivial and imprecise: IL-6 SMD −0.17 (95% CI −0.56 to 0.23; p = 0.41; I² = 55%); IL-8 SMD −0.30 (95% CI −0.62 to 0.01; p = 0.06; I² = 0%); IL-10 SMD −0.10 (95% CI −0.83 to 0.63; p = 0.79; I² = 81%); and TNF-α SMD −0.09 (95% CI −0.45 to 0.27; p = 0.62; I² = 33%). Individual trials reported reductions in biomarkers in high-exposure or diseased populations. GRADE ratings were as follows: IL-6 very low, IL-8 moderate, IL-10 low, and TNF-α moderate. Current RCT evidence demonstrates inconsistent, often trivial effects of phytocannabinoid interventions on circulating inflammatory biomarkers. Full article

Triatoma infestans is one of the primary vectors of Chagas disease. This vector has developed increasing resistance to pyrethroids, the main insecticides used for its control. Recent studies have highlighted the repellent and lethal effects of Cannabis sativa on insects, suggesting its potential use in pest management. Based on this, we hypothesize that C. sativa could be a viable bioactive for controlling T. infestans. To test this hypothesis, acetone and ethanol extracts were obtained from the inflorescences of C. sativa L. (Deep Mandarine variety) using sonication. These extracts were analyzed through gas chromatography and high-performance liquid chromatography. The repellent and lethal effects of the extracts were evaluated on fifth-instar nymphs of T. infestans from a laboratory colony, as well as on the beneficial non-target species, Apis mellifera. The most abundant terpenes identified were β-caryophyllene and β-pinene, with concentrations exceeding 100 ppm in both extracts. Cannabidiol and Δ⁹-tetrahydrocannabinol were the predominant cannabinoids. Both extracts exhibited maximum lethal activity 48 h after insect contact, with the acetone extract demonstrating a potency five times greater than the ethanolic extract. Binary combinations of C. sativa extracts with major terpenes showed dose-dependent interactions against T. infestans, ranging from strong synergy (e.g., AE + β-caryophyllene, CI = 0.06–0.17) to marked antagonism (e.g., AE + E-ocimene, CI = 1.60–4.80). Furthermore, the acetone extract showed a more effective repellent action compared to the ethanol extract, even outperforming N,N-Diethyl-meta-toluamide (DEET, positive control). At a concentration of 25 µg/cm² for 60 min, the acetone extract achieved a 100% repellent effect, whereas DEET required a concentration of 50 µg/cm² to achieve the same effect. Unlike imidacloprid (positive control), neither extract showed toxicity to adult A. mellifera at the evaluated doses. Full article

Background/Objectives: Cannabis is the most widely used illicit substance worldwide, particularly among young adults, with growing acceptance following medical and recreational legalization. Although generally perceived as a drug with low acute toxicity, an expanding body of evidence indicates that cannabinoids can exert relevant cardiovascular effects, including arrhythmias, myocardial ischemia, and sudden cardiac death (SCD). These mechanisms are mediated through complex, dose-dependent interactions among CB1 and CB2 receptors, autonomic imbalance, and endothelial dysfunction. Nevertheless, cannabis-related fatalities remain underestimated in both clinical and forensic settings. Case presentation: Three cases of sudden unexpected death in previously healthy men aged 28, 37, and 37 years are described. All were found deceased at home under non-suspicious circumstances. Forensic autopsies ruled out trauma, coronary atherosclerosis, congenital malformations, or cardiomyopathy. Histological analyses consistently revealed polymorphic myocardial alterations, including interstitial edema, fiber disruption, and focal myocytolysis, without inflammatory infiltrates or necrosis. Toxicological examinations demonstrated the presence of Δ9-tetrahydrocannabinol (THC) and metabolites in peripheral blood and urine, while alcohol and other illicit drugs tested negative. In each case, the cause of death was attributed to arrhythmic sudden cardiac death in temporal association with cannabis use. Conclusions: This case series, integrated with a narrative review of current literature, supports the hypothesis that cannabis consumption can contribute to fatal arrhythmias even in young adults without conventional cardiovascular risk factors. The convergence of autopsy, histopathological, and toxicological findings suggests a potential causal link between THC exposure and sudden unexpected death. These results highlight the importance of systematic postmortem investigations in suspected drug-related fatalities and underscore the need for greater awareness among clinicians, forensic pathologists, and policymakers regarding the underestimated cardiovascular toxicity of cannabis. Full article

The effects of Δ⁹-tetrahydrocannabinol (THC) on adipocyte function under obesogenic, free-fatty-acid (FFA)-rich conditions remain poorly characterized, particularly regarding adipogenesis, FFA buffering, and downstream hepatocyte lipid handling. We investigated THC’s effect on adipogenic differentiation, temporal FFA buffering in mature adipocytes under lipid stress, and hepatocyte lipid accumulation driven by extracellular FFAs. The 3T3-L1 preadipocytes were differentiated in 0.5 mM oleate: palmitate (2:1) medium with vehicle (EtOH), THC (1 μM), or rosiglitazone (30 μM). Adipogenesis was assessed using BODIPY/NucSpot 650 staining followed by lipid droplet (LD) analysis. Adipocytes (days 10–18) were monitored for lipid accumulation, LD morphology, lipolysis, extracellular non-esterified fatty acids (NEFA), and lipid-handling gene expression. Conditioned media (CM) were applied to AML12 hepatocytes to assess lipid uptake. By day 6, THC enhanced adipogenesis, increasing lipid accumulation. In mature adipocytes, THC induced a biphasic buffering response: on day 10, NEFA levels were elevated despite unchanged lipid content, with increased isoproterenol-stimulated lipolysis. By day 18, buffering improved, with enhanced lipid storage, elevated stimulated lipolysis, smaller LDs, and altered gene expression. AML12 lipid accumulation corresponded with residual NEFA in CM, indicating that adipocyte FFA sequestration modulates hepatocyte lipid uptake. These findings reveal that under FFA-rich conditions, THC promotes late-stage adipogenesis and remodels adipocyte lipid handling, regulating extracellular FFA availability and hepatocyte lipid loading. Full article

Although cannabis is used in a wide range of fields, including medicine and pharmacology, its use is prohibited in Japan because it contains Δ⁹-tetrahydrocannabinol (Δ⁹-THC), a compound that exhibits narcotic effects. While cannabis is primarily detected via color-based screening methods at crime scenes, the reaction products and mechanisms associated with these screening methods have not been fully elucidated. To address this issue, the colored products were isolated via the diazo-coupling reactions of the major cannabinoids (cannabidiol, cannabinol, and Δ⁹-THC) in cannabis with the Fast Blue RR diazonium salt, and their structures were determined using NMR spectroscopy. As expected, azo compound 2 was formed from cannabidiol, whereas cannabinol and Δ⁹-THC produced quinoneimines 3 and 4, respectively. This study is expected to lead to the future development of more sensitive color-based reagents that produce fewer false positives. Full article

Background/Objectives: Cannabinoid use is rising among patients undergoing spinal fusion, yet its influence on bone healing is poorly defined. The endocannabinoid system (ECS)—through cannabinoid receptors 1 (CB1) and 2 (CB2)—modulates skeletal metabolism. We reviewed preclinical, mechanistic and clinical evidence to clarify how individual cannabinoids affect fracture repair and spinal arthrodesis. Methods: PubMed, Web of Science and Scopus were searched from inception to 31 May 2025 with the terms “cannabinoid”, “CB1”, “CB2”, “spinal fusion”, “fracture”, “osteoblast” and “osteoclast”. Animal studies, in vitro experiments and clinical reports that reported bone outcomes were eligible. Results: CB2 signaling was uniformly osteogenic. CB2-knockout mice developed high-turnover osteoporosis, whereas CB2 agonists (HU-308, JWH-133, HU-433, JWH-015) restored trabecular volume, enhanced osteoblast activity and strengthened fracture callus. Cannabidiol (CBD), a non-psychoactive phytocannabinoid with CB2 bias, accelerated early posterolateral fusion in rats and reduced the RANKL/OPG ratio without compromising final union. In contrast, sustained or high-dose Δ⁹-tetrahydrocannabinol (THC) activation of CB1 slowed chondrocyte hypertrophy, decreased mesenchymal-stromal-cell mineralization and correlated clinically with 6–10% lower bone-mineral density and a 1.8–3.6-fold higher pseudarthrosis or revision risk. Short-course or low-dose THC appeared skeletal neutral. Responses varied with sex, age and genetic background; no prospective trials defined safe perioperative dosing thresholds. Conclusions: CB2 activation and CBD consistently favor bone repair, whereas chronic high-THC exposure poses a modifiable risk for nonunion in spine surgery. Prospective, receptor-specific trials stratified by THC/CBD ratio, patient sex and ECS genotype are needed to establish evidence-based cannabinoid use in spinal fusion. Full article

Background: Sodium–glucose cotransporter 2 (SGLT2) inhibitors have transformed type 2 diabetes mellitus (T2DM) management by promoting glucosuria, lowering glycated hemoglobin (HbA1c), blood pressure, and weight; however, their use is limited by genitourinary infections and ketoacidosis. Phytocannabinoids—bioactive compounds from Cannabis sativa—exhibit multi-target pharmacology, including interactions with cannabinoid receptors, Peroxisome Proliferator-Activated Receptors (PPARs), Transient Receptor Potential (TRP) channels, and potentially SGLT2. Objective: To evaluate the potential of phytocannabinoids as novel modulators of renal glucose reabsorption via SGLT2 and to compare their efficacy, safety, and pharmacological profiles with synthetic SGLT2 inhibitors. Methods: We performed a narrative review encompassing the following: (1) the molecular and physiological roles of SGLT2; (2) chemical classification, natural sources, and pharmacokinetics/pharmacodynamics of major phytocannabinoids (Δ⁹-Tetrahydrocannabinol or Δ⁹-THC, Cannabidiol or CBD, Cannabigerol or CBG, Cannabichromene or CBC, Tetrahydrocannabivarin or THCV, and β-caryophyllene); (3) in silico docking and drug-likeness assessments; (4) in vitro assays of receptor binding, TRP channel modulation, and glucose transport; (5) in vivo rodent models evaluating glycemic control, weight change, and organ protection; (6) pilot clinical studies of THCV and case reports of CBD/BCP; (7) comparative analysis with established synthetic inhibitors. Results: In silico studies identify high-affinity binding of several phytocannabinoids within the SGLT2 substrate pocket. In vitro, CBG and THCV modulate SGLT2-related pathways indirectly via TRP channels and CB receptors; direct IC₅₀ values for SGLT2 remain to be determined. In vivo, THCV and CBD demonstrate glucose-lowering, insulin-sensitizing, weight-reducing, anti-inflammatory, and organ-protective effects. Pilot clinical data (n = 62) show that THCV decreases fasting glucose, enhances β-cell function, and lacks psychoactive side effects. Compared to synthetic inhibitors, phytocannabinoids offer pleiotropic benefits but face challenges of low oral bioavailability, polypharmacology, inter-individual variability, and limited large-scale trials. Discussion: While preclinical and early clinical data highlight phytocannabinoids’ potential in SGLT2 modulation and broader metabolic improvement, their translation is impeded by significant challenges. These include low oral bioavailability, inconsistent pharmacokinetic profiles, and the absence of standardized formulations, necessitating advanced delivery system development. Furthermore, the inherent polypharmacology of these compounds, while beneficial, demands comprehensive safety assessments for potential off-target effects and drug interactions. The scarcity of large-scale, well-controlled clinical trials and the need for clear regulatory frameworks remain critical hurdles. Addressing these aspects is paramount to fully realize the therapeutic utility of phytocannabinoids as a comprehensive approach to T2DM management. Conclusion: Phytocannabinoids represent promising multi-target agents for T2DM through potential SGLT2 modulation and complementary metabolic effects. Future work should focus on pharmacokinetic optimization, precise quantification of SGLT2 inhibition, and robust clinical trials to establish efficacy and safety profiles relative to synthetic inhibitors. Full article

New psychoactive substances (NPSs) are emerging narcotics or psychotropics that pose a public health risk. The most commonly reported NPSs are synthetic cannabinoids and synthetic cathinones. Synthetic cannabinoids mimic the effects of Δ9-tetrahydrocannabinol (Δ9-THC), often with greater potency, while synthetic cathinones act as stimulants, frequently serving as cheaper alternatives to amphetamines, 3,4-methylenedioxymethamphetamine (MDMA) and cocaine. While some synthetic cannabinoids exhibit chirality depending on their synthesis precursors, synthetic cathinones are intrinsically chiral. Biotargets can recognize and differentiate between enantiomers, leading to distinct biological responses (enantioselectivity). Understanding these differences is crucial; therefore, the development of enantioresolution methods to assess the biological and toxicological effects of enantiomer is necessary. This work systematically compiles enantioselectivity studies and enantioresolution methods of synthetic cannabinoids and synthetic cathinones, following PRISMA guidelines. The main aim of this review is to explore the impact of chirality on these NPSs, improving our understanding of their toxicological behavior and evaluating advances in analytical techniques for their enantioseparation. Key examples from both groups are presented. This review highlights the importance of continuing research in this field, as demonstrated by the differing properties of synthetic cannabinoid and synthetic cathinone enantiomers, which are closely linked to variations in biological and toxicological outcomes. Full article

5F-ADB, MDMB-4en-PINACA and ADB-4en-PINACA are three potent indazole-carboxamide synthetic cannabinoids (SCs) that have been widely abused in recent years. However, the pharmacological research on these compounds remains limited, especially in vivo research data. The purpose of the present study was to investigate the pharmacological effects of 5F-ADB, MDMB-4en-PINACA and ADB-4en-PINACA in mice, comparing their in vivo effects with those caused by Δ⁹-tetrahydrocannabinol (Δ⁹-THC), the main psychoactive substance in cannabis. We evaluated the cannabinoid-specific pharmacological effects of 5F-ADB, MDMB-4en-PINACA and ADB-4en-PINACA using the tetrad assay (locomotion inhibition, hypothermia, analgesia and catalepsy). Then we conducted conditioned place preference (CPP) and precipitated withdrawal assay to assess the rewarding effect and physical dependence, with Δ⁹-THC as a positive control. The results showed that all of the three SCs exhibited potential tetrad effects in a dose-dependent manner, with median effective dose (ED₅₀) values ranging from 0.03 to 0.77 mg/kg. In the CPP tests, they all exhibited a significant biphasic effect of conditioned place preference (CPP) and conditioned place aversion (CPA). A significant increase in paw tremors and head twitches was observed in the rimonabant-precipitated withdrawal assay, indicating that the repeated administration of these SCs can lead to potential physical dependence. All effective doses were lower than Δ⁹-THC. These findings strongly suggested that the three SCs exhibited similar but stronger cannabinoid-specific tetrad effects, rewarding effect and physical dependence compared with Δ⁹-THC, indicating their high abuse potential and possible threats to human health. The rank order of abuse potential for these drugs was 5F-ADB > MDMB-4en-PINACA > ADB-4en-PINACA > Δ⁹-THC. Full article

Background/Objectives: The industrial extraction and purification processes of Cannabis sativa L. compounds are critical steps in creating formulations with reliable and reproducible therapeutic and sensorial attributes. Methods: For this study, standardized preparations of chemotype I were chemically analyzed, and the sensory attributes were studied to characterize the extraction and purification processes, ensuring the maximum retention of cannabinoids and minimization of other secondary metabolites. The industrial process used deep-cooled ethanol for selective extraction. Results: Taking into consideration that decarboxylation occurs in the process, the cannabinoid profile composition was preserved from the herbal substance to the herbal preparations, with wiped-film distillation under deep vacuum conditions below 0.2 mbar, as a final purification step. The profiles of the terpenes and cannabinoids in crude and purified Full-spectrum Extract Cannabis Oil (FECO) were analyzed at different stages to evaluate compositional changes that occurred throughout processing. Subjective intensity and acceptance ratings were received for taste, color, overall appearance, smell, and mouthfeel of FECO preparations. Conclusions: According to sensory analysis, purified FECO was more accepted than crude FECO, which had a stronger and more polarizing taste, and received higher ratings for color and overall acceptance. In contrast, a full cannabis extract in the market resulted in lower acceptance due to taste imbalance. The purification process effectively removed non-cannabinoids, improving sensory quality while maintaining therapeutic potency. Terpene markers of the flower were remarkably preserved in SOMAÍ’s preparations’ fingerprint, highlighting a major qualitative profile reproducibility and the opportunity for their previous separation and/or controlled reintroduction. The study underscores the importance of monitoring the extraction and purification processes to optimize the cannabinoid content and sensory characteristics in cannabis preparations. Full article

Cannabis sativa is a remarkable source of bioactive compounds, with over 150 distinct phytocannabinoids identified to date. Among these, cannabinoids are gaining attention as potential therapeutic agents for neurodegenerative diseases. Previous research showed that cannabinol (CBN), a minor cannabinoid derived from Δ⁹-tetrahydrocannabinol, exhibits antioxidant, anti-inflammatory, analgesic, and anti-bacterial effects. The objective of this study was to assess the protective potential of 24 h CBN pre-treatment, applied at different concentrations (5 µM, 10 µM, 20 µM, 50 µM, and 100 µM), in differentiated neuroblastoma × spinal cord (NSC-34) cells. Transcriptomic analysis was performed using next-generation sequencing techniques. Our results reveal that CBN had no negative impact on cell viability at the tested concentrations. Instead, it showed a significant effect on stress response and neuroplasticity-related processes. Specifically, based on the Reactome database, the biological pathways mainly perturbed by CBN pre-treatment were investigated. This analysis highlighted a significant enrichment in the Reactome pathway’s cellular response to stress, cellular response to stimuli, and axon guidance. Overall, our results suggest that CBN holds promise as an adjuvant agent for neurodegenerative diseases by modulating genes involved in neuronal cell survival and axon guidance. Full article