A different ultrastructural face of ribbon synapses in the rat retina

Abstract Ribbon synapses located exclusively within retinal, cochlear and vestibular connections belong to the most interesting cellular structures but their molecular nature and functions had remained unclear. The study has provided a descriptive morphological analysis of rat eye ribbon synapses using high-resolution transmission electron microscopy (TEM). An original collection of untypical, rarely present in the literature sagittal or tangential sections through the single RIBEYE domain of the particular ribbon have been delivered

Spexin and nesfatin-1-expressing neurons in the male human claustrum

Neuropeptides are involved in numerous brain activities being responsible for a wide spectrum of higher mental functions. The purpose of this concise, structural and qualitative investigation was to map the possible immunoreactivity of the novel regulatory peptides: spexin (SPX) and nesfatin-1 within the human claustrum. SPX is a newly identified peptide, a natural ligand for the galanin receptors (GALR) 2/3, with no molecular structure similarities to currently known regulatory factors. SPX seems to have multiple physiological functions, with an involvement in reproduction and food-intake regulation recently revealed in animal studies. Nesfatin-1, a second pleiotropic neuropeptide, which is a derivative of the nucleobindin-2 (NUCB-2) protein, is characterized by a wide distribution in the brain. Nesfatin-1 is a substance with a strong anorexigenic effect, playing an important role in the neuronal circuits of the hypothalamus that regulate food intake and energy homeostasis. On the other hand, nesfatin-1 may be involved in several important brain functions such as sleep, reproductive behaviour, cognitive processes, stress responses and anxiety. For the first time we detected and described a population of nesfatin-1 and SPX expressing neurons in the human claustrum using immunohistochemical and fluorescent methods. The study presents the novel identification of SPX and nesfatin-1 immunopositive neurons in the human claustrum and their assemblies show similar patterns of distribution in the whole structure

The importance of polymorphism in MC1R and ASIP genes for hair color prediction in forensic aspect

Problem predykcji fenotypu na podstawie genotypu jest istotnym zagadnieniem badawczym w biologii, medycynie i genetyce sądowej. Wyniki badań asocjacyjnych umożliwiają lepsze poznanie wpływu genów na fenotyp człowieka, otwierają drogę do tzw. medycyny spersonalizowanej, a w kryminalistyce mogą być wykorzystane do opisu sprawcy przestępstwa. Prowadzone w ostatnich latach badania nad predykcją koloru włosów, a zwłaszcza nad problemem dziedziczenia rudego koloru włosów wykazały istotną zależność pomiędzy tą cechą fizyczną, a zmiennością w obrębie genu MC1R. Niedawne badania ogólnogenomowe wskazały też na możliwe znaczenie polimorfizmu genu ASIP w determinacji rudego koloru włosów. Stwierdzone asocjacje są interesujące w kontekście wzajemnego oddziaływania produktów obu genów na poziomie molekularnym. Celem naszych badań była ocena znaczenia wyselekcjonowanych polimorfizmów kandydackich w powyższych genach w populacji 396 osób z populacji Polskiej o zdefiniowanym fenotypie pigmentowym, w tym 96 osób o rudym kolorze włosów. Metodą minisekwencjonowania przeanalizowano kilkanaście pozycji typu SNP w genach MC1R i ASIP. Badania pozwoliły na wykazanie asocjacji 2 pozycji w genie ASIP oraz kilku polimorfizmów w genie MC1R z rudym kolorem włosów w badanej populacji. Analiza zmienności genu ASIP pozwala na zwiększenie precyzji predykcji rudego koloru włosów, co jest szczególnie użyteczne w aspekcie kryminalistycznym. Dotychczasowe wyniki są bardzo obiecujące, dlatego celowe wydaje się kontynuowanie badań nad predykcją fenotypu pigmentacyjnego również w kontekście sądowym.The problem of predicting phenotype from genotype is an important research topic in biology, medicine and forensic genetics. The results of association studies provide a better understanding of the impact of genes on the human phenotype, opening the way for the so-called personalized medicine and in forensics can be used for description of an offender. Research conducted in recent years on the prediction of hair color, especially on inheritance of red hair color showed a significant association between this physical characteristic and variation in the MC1R gene. Recent Genome Wide Association Studies have also indicated a possible role of polymorphism in ASIP in determination of red hair color. The observed associations are interesting in the context of interaction between the products of both genes at the molecular level. The aim of our study was to assess the significance of selected polymorphisms in these candidate genes in a population of 396 individuals from a population sample of Poles with a defined pigmentation phenotype, including 96 individuals with red hair color. Using minisequencing procedure several SNP in the genes MC1R and ASIP were investigated. The study allowed us to demonstrate the association of two positions in the gene ASIP and several polymorphism in the MC1R gene with red hair color in the studied population sample. Analysis of the ASIP gene variation can increase the accuracy of prediction of red hair color, which is particularly useful in forensic examinations. The results obtained so far are very promising and thus it seems to be purposeful to continue research on prediction of pigmentation phenotype characteristics including forensic aspect

The GnRH analogues affect novel neuropeptide SMIM20/phoenixin and GPR173 receptor expressions in the female rat hypothalamic-pituitary-gonadal (HPG) axis

The recently discovered peptide phoenixin (PNX) and its receptor GPR173 are novel factors that exhibit a large spectrum of regulatory activity, especially when considered as a central modulator of GnRH-related hormonal control of reproductive processes. It has been already proven that GnRH agonists and antagonists can modulate peptidergic signaling in the HPG axis. Despite these findings, there is so far no information regarding the influence of treatment with GnRH analogues on SMIM20/phoenixin signaling in the hypothalamic-pituitary-gonadal axis. In the current study we measured SMIM20/phoenixin and GPR173 mRNA levels in the hypothalamus, pituitary and ovaries of female rats in the diestrus phase following treatment with GnRH-R agonist (buserelin) and antagonist (cetrorelix) using quantitative Real-Time PCR. The serum PNX concentrations were also estimated with ELISA technique. Results: The hypothalamic, hypophyseal and especially ovarian levels of SMIM20 mRNA were increased after both buserelin and cetrorelix administration. The GPR173 expressions were in turn decreased in the hypothalamus and pituitary. Treatment with the GnRH analogues led to the modulation of SMIM20/phoenixin and GPR173 mRNA expression in the female rat hypothalamic-pituitary-gonadal axis. By identifying buserelin and cetrorelix as novel modulators of phoenixin signalling in the animal HPG axis, these results cast new light on the GnRH analogues mode of action and contribute to a better understanding of the mechanisms responsible for the hormonal control of reproduction

The first identification of nesfatin-1-expressing neurons in the human bed nucleus of the stria terminalis

Neuropeptides are involved in various brain activities being able to control a wide spectrum of higher mental functions. The purpose of this concise structural investigation was to detect the possible immunoreactivity of the novel multifunctional neuropeptide nesfatin-1 within the human bed nucleus of the stria terminalis (BNST). The BNST is involved in the mechanism of fear learning, integration of stress and reward circuits, and pathogenesis of addiction. Nesfatin-1-expressing neurons were identified for the first time in several regions of the BNST using both immunohistochemical and fluorescent methods. This may implicate a potential contribution of this neuropeptide to the BNST-related mechanisms of stress/reward responses in the human brain