Towards zebrafish models to unravel translational insights of obsessive-compulsive disorder: a neurobehavioral perspective

Obsessive-compulsive disorder (OCD) is a chronic and debilitating illness that has been considered a polygenic and multifactorial disorder, challenging effective therapeutic interventions. Although invaluable advances have been obtained from human and rodent studies, several molecular and mechanistic aspects of OCD etiology are still obscure. Thus, the use of non-traditional animal models may foster innovative approaches in this field, aiming to elucidate the underlying mechanisms of disease from an evolutionary perspective. The zebrafish (Danio rerio) has been increasingly considered a powerful organism in translational neuroscience research, especially due to the intrinsic features of the species. Here, we outline target mechanisms of OCD for translational research, and discuss how zebrafish-based models can contribute to explore neurobehavioral aspects resembling those found in OCD. We also identify possible advantages and limitations of potential zebrafish-based models, as well as outline future directions in both etiological and therapeutic research. Lastly, we reinforce the use of zebrafish as a promising tool to unravel the biological bases of OCD, as well as novel pharmacological therapies in the field.

Dietary Supplementation with R-(+)-Limonene Improves Growth, Metabolism, Stress, and Antioxidant Responses of Silver Catfish Uninfected and Infected with Aeromonas hydrophila

R-(+)-limonene is a monoterpene from plants of the genus Citrus with diverse biological properties. This research evaluated the effects of dietary supplementation with R-(+)-limonene on growth, metabolic parameters in plasma and liver, and the antioxidant and stress responses in silver catfish, Rhamdia quelen, challenged or not with Aeromonas hydrophila. Fish were fed for 67 days with different doses of R-(+)-limonene in the diet (control 0.0, L0.5, L1.0, and L2.0 mL/kg of diet). On the 60th day, a challenge with A. hydrophila was performed. R-(+)-limonene in the diet potentiated the productive performance of the fish. The metabolic and antioxidant responses indicate that R-(+)-limonene did not harm the health of the animals and made them more resistant to the bacterial challenge. Histological findings showed the hepatoprotective effect of dietary R-(+)-limonene against A. hydrophila. Igf1 mRNA levels were upregulated in the liver of fish fed with an L2.0 diet but downregulated with bacterial challenge. The expression levels of crh mRNA were higher in the brains of fish fed with the L2.0 diet. However, the L2.0 diet downregulated crh and hspa12a mRNA expression in the brains of infected fish. In conclusion, the results indicated that R-(+)-limonene can be considered a good dietary supplement for silver catfish.

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

One of the major causes of early pregnancy loss is heat stress. In ruminants, interferon tau (IFNT) is the embryo signal to the mother. Once the interferon signaling pathway is activated, it drives gene expression for interferon-stimulated genes (ISGs) and alters neutrophils responses. The aim of the present study was to evaluate interferon (IFN) pathway, ISGs and gene expression in polymorphonuclear leukocytes (PMN) and oxidative stress in dairy cows under heat stress. Pregnant cows had their estrous cycle synchronized and randomly assigned to a comfort or heat stress group. Blood samples were collected at artificial insemination (AI) and on Days 10, 14 and 18 following AI. Pregnant cows were pregnancy checked by ultrasound on Day 30 and confirmed on Day 60 post-AI. Results are presented as mean ± SEM. The corpus luteum (CL) diameter was not different between groups of pregnant cows; concentration of progesterone of pregnant cows on Day 18 following AI was greater in comfort group compared to heat stressed group. Comfort pregnant cows had higher expression of all analyzed genes from interferon pathway, except for IFNAR1, on both Days 14 and 18. Conversely, heat stressed cows did not show altered expression of IFNT pathway genes and ISGs between Days 10, 14, and 18 after AI. The oxidative stress, determined as malondialdehyde (MDA) levels, was greater in heat stress group on Days 10, 14 and 18, independent of pregnancy status. Heat stress negatively influences expression of ISGs, IFN pathway gene expression in neutrophils, and oxidative stress. Our data suggest that lower conception rates in cows under heat stress are multifactorial, with the association of interferon pathway activation and the unbalanced oxidative stress being main contributing factors.

Aspectos anatômicos da macro e microvascularização da placenta em ovinos (Ovis aries)

A placenta possui sistemas vasculares essenciais e intimamente associados. A sua efetividade está relacionada ao tipo de fluxo sanguíneo entre as circulações materno e fetal e assim com a morfologia da vascularização. Esta pesquisa teve como objetivo, estudar os aspectos anatômicos da vascularização macro e microscópica da placenta de ovinos, mestiços das raças Corriedale e Ideal, que vivem próximos do nível do mar e a sistematização dos vasos fetais desde o funículo umbilical até o leito capilar. Os cotilédones dos ovinos são esferóides na sua maioria e recebem de um a quatro ramos vasculares em sua concavidade central. Anastomoses dos vasos do funículo umbilical ocorrem somente entre artérias. Entre os ramos dos vasos coriônicos, as anastomoses são mais freqüentes em veias do que nas artérias. Foram encontrados 187 tipos de arranjos arteriocotiledonários diferentes. A artéria coriônica dirigida ao corno gestante possui um trajeto mais curto e emite menos ramos cotiledonários que a do corno não gestante. A veia coriônica é formada pela confluência de dois ramos e recebe confluentes colaterais que freqüentemente se anastomosam entre si. A microvascularização do cotilédone fetal foi estudada em microscopia eletrônica de varredura e está representada pela presença de árvores vilosas cônicas e com relato de alças capilares em forma de leque. As características microscópicas da placenta refletemas características do desenvolvimento viloso placentário determinada pela altitude na qual os animais vivem (a 95 m do nível do mar).

Association between IGF-IR gene polymorphisms and productive and reproductive traits in Holstein cows

The association between single-strand conformation polymorphism (SSCP) in the gene of insulin-like growth factor-I receptor (IGF-IR) and age at first calving (AFC), calving interval (CI), lactation length (LL), and milk yield (MY) was studied using 106 graded Holstein females. The polimerase chain reaction (PCR) with specific initiating oligonucleotides, resulted an amplified fragment of 335pb. The population genotypes frequencies were 82.1% and 17.9%, for AA and AB genotypes, respectively. The frequency of A allele was 0.91 and 0.09 of B allele. No association between the identified polymorphism and AFC, CI, and MY was observed. The LL was positively associated (P<0.05) with the absence of B allele. Animals carrying the AA genotype presented a longer lactation period.