The Use of Anti-VDAC2 Antibody for the Combined Assessment of Human Sperm Acrosome Integrity and Ionophore A23187-Induced Acrosome Reaction

Voltage-dependent anion channel (VDAC) is mainly located in the mitochondrial outer membrane and participates in many biological processes. In mammals, three VDAC subtypes (VDAC1, 2 and 3) have been identified. Although VDAC has been extensively studied in various tissues and cells, there is little knowledge about the distribution and function of VDAC in male mammalian reproductive system. Several studies have demonstrated that VDAC exists in mammalian spermatozoa and is implicated in spermatogenesis, sperm maturation, motility and fertilization. However, there is no knowledge about the respective localization and function of three VDAC subtypes in human spermatozoa. In this study, we focused on the presence of VDAC2 in human spermatozoa and its possible role in the acrosomal integrity and acrosome reaction using specific anti-VDAC2 monoclonal antibody for the first time. The results exhibited that native VDAC2 existed in the membrane components of human spermatozoa. The co-incubation of spermatozoa with anti-VDAC2 antibody did not affect the acrosomal integrity and acrosome reaction, but inhibited ionophore A23187-induced intracellular Ca2+ increase. Our study suggested that VDAC2 was located in the acrosomal membrane or plasma membrane of human spermatozoa, and played putative roles in sperm functions through mediating Ca2+ transmembrane transport

Three-dimensional atlases of insect brains

The morphological structure of the nervous system is ultimately the basis of its function. Analyses of the anatomical layout of brain areas, single neuron morphologies, and the synaptic connectivity of neurons are therefore essential for a comprehensive understanding of the computational processes implemented in neuronal networks. Insect brains have long served as models to examine neuronal circuits that process sensory information, provide the substrates for learning and memory, or generate motor patterns that drive well-studied behavior. The relatively small number of neurons these brains are composed of (up to one million) and their small overall size make them easily accessible for physiological and anatomical research. To aid the comparison of results within and across species, and thus make it possible to relate function to anatomical structure, printed brain atlases have been used as a common frame of reference for many decades. In recent years, digital, three-dimensional atlases were generated to provide geometrical as well as conceptual reference systems for the brains of several insect species. In this review we compare the different approaches for generating such three-dimensional atlases. We highlight the key problems that must be overcome during this process and the solutions that have been found to achieve this. The advantages and limitations of the different strategies are discussed, and the applications that have so far resulted from the implementation of these atlases are described