Adult neurogenesis persists in the adult mammalian brain due to the existence of neural stem cell (NSC) reservoirs in defined niches, where they give rise to new neurons throughout life. Recent research has begun to address the implication of constitutive (basal) autophagy in the regulation of neurogenesis in the mature brain. This review summarizes the current knowledge on the role of autophagy-related genes in modulating adult NSCs, progenitor cells and their differentiation into neurons. The general function of autophagy in neurogenesis in several areas of the embryonic forebrain is also revisited. During development, basal autophagy regulates Wnt and Notch signaling and is mainly required for adequate neuronal differentiation. The available data in the adult indicate that the autophagy-lysosomal pathway regulates adult NSC maintenance, the activation of quiescent NSCs, the survival of the newly born neurons and the timing of their maturation. Future research is warranted to validate the results of these pioneering studies, refine the molecular mechanisms underlying the regulation of NSCs and newborn neurons by autophagy throughout the life-span of mammals and provide significance to the autophagic process in adult neurogenesis-dependent behavioral tasks, in physiological and pathological conditions. These lines of research may have important consequences for our understanding of stem cell dysfunction and neurogenic decline during healthy aging and neurodegeneration.

The present study was designed to prove new rabbit insemination extenders containing aminopeptidase inhibitors (AMIs) with or without chitosan (CS)-dextran sulfate (DS) nanoparticles entrapping the GnRH analogue. In addition, different hormone concentrations were tested in these extenders, evaluating their in vivo effect on rabbit reproductive performance after artificial insemination. A total of 911 females were inseminated with semen diluted with the four experimental extenders (C4 group: 4 μg buserelin/doe in control medium (Tris-citric acid-glucose supplemented with bestatin 10 μM and EDTA 20 mM), C5 group: 5 μg of buserelin/doe in control medium, Q4 group: 4 μg of buserelin/doe into CS-DS nanoparticles in control medium, Q5 group: 5 μg of busereline/doe into CS-DS nanoparticles in control medium). Results showed that fertility was significantly lower in C4 group compared to C5, Q5 and Q4 groups (0.7 versus 0.85, 0.85 and 0.82, respectively). On the contrary, prolificacy was similar in the four experimental groups studied (P > 0.05). We conclude that the CS-DS nanoparticles prepared by a coacervation process as carrier for buserelin acetate allows reducing the concentration of hormone used in extenders supplemented with bestatin and EDTA without affecting the fertility and prolificacy of rabbit females.

The study was designed to evaluate the influence of genetic origin on rabbit seminal plasma protein profile variation along the year. Seminal plasma of rabbits from line A (maternal line) and R (paternal line) collected during a natural year was subjected to polyacrylamide gel electrophoresis (SDS-PAGE). The electrophoretic profile of rabbit seminal plasma resulted in multiple protein bands of different intensity ranging from 9 to 240 kDa. Results showed that seven protein bands were significantly different between genetic lines, and among these, three protein bands were significantly different between seasons. The differentially expressed proteins were identified by MALDI-TOF/TOF or LC-MS/MS analysis and were the following ones: FAM115E-like (220, 113 and 59 kDa), ectonucleoside triphosphate diphosphohydrolase 3 isoform X2 (72 kDa), annexin A5 (32 kDa), lipocalin allergen Ory c 4 precursor (19 kDa), and haemoglobin subunit zetalike (13 kDa) between genetic lines and FAM115E-like (113 kDa), haemoglobin subunit zetalike (13 kDa) and β-nerve growth factor (12 kDa) between seasons. These results indicate that proteins from rabbit seminal plasma are under both seasonal control and genetic control. Furthermore, the differential presence of these proteins could be one of the causes explaining the differences observed in fertility and seminal parameters between these two lines in earlier studies.

The objective of this study was to determine rabbit seminal plasma enzyme activity. Furthermore, correlations between semen parameters and enzyme activity and male age were examined. The study was performed using 17 New Zealand White males from 5 to 9 mo old. Overall, 252 semen samples were collected from bucks from May to September. Semen characteristics were analysed and the seminal plasma was obtained by centrifugation. The activities of alanyl aminopeptidase (APN), aspartate transaminase (AST), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALKP) in the seminal plasma fluid were measured. Significant differences between males were found in APN, GGT, LDH, ALKP and ALT activities (P<0.05). No significant differences between enzyme activity and male age were found. We also observed significant positive correlations between male age and sperm concentration (r=0.26), progressive motility (r=0.17) and amplitude of lateral head displacement (r=0.21), and negative ones between male age and average path velocity (r=-0.56), velocity of the sperm head along its actual curvilinear path (r=-0.61), straight line velocity (r=-0.50), linearity index (r=-0.13), and cytoplasmic droplet (r=-0.33). Furthermore, a significant negative correlation between APN activity and the status of the acrosome (r=-0.20) and significant positive correlations between APN activity and the sperm abnormalities (r=0.21), GGT activity and sperm concentration (r=0.34) and the status of the acrosome (r=0.31), and ALKP activity and sperm concentration were observed (r=0.41). In our study, APN and GGT seem to be the most predictive enzymes for rabbit semen quality.

Contents This study was designed to develop chitosan (CS)–dextran sulphate (DS) nanoparticles containing a GnRH analogue and to study their effect on rabbit (Oryctolagus cuniculus) semen quality. Six experimental extenders were tested as follows: (control) Tris‐citric acid‐glucose (TCG), (1) 0.05% CS‐0.05% DS (4:1), (2) 0.1% CS‐0.05% DS (4:1), (3) 0.05% CS‐0.05% DS (3:1), (4) 0.1% CS‐0.05% DS (3:1), (5) 0.1% CS‐0.05% DS (2:1). CS and DS were dissolved in TCG medium, and nanoparticles were obtained through magnetic stirring. Rabbit seminal samples were incubated up to 5 hr at 37°C in the extenders, and seminal quality was evaluated. The entrapment efficiency was 40%–50%. After 5 hr at 37°C, a 20% of the hormone was released. Results showed that the presence of CS‐DS nanoparticles did not affect rabbit semen motility, viability and membrane functionality; however, acrosome integrity was significantly higher versus control (p < .001).