The role of the Ventral Nucleus of the Trapezoid Body in the auditory prepulse inhibition of the acoustic startle reflex.

Cholinergic signaling is essential to mediate the auditory prepulse inhibition (PPI), an operational measure of sensorimotor gating, that refers to the reduction of the acoustic startle reflex (ASR) when a low-intensity, non-startling acoustic stimulus (the prepulse) is presented just before the onset of the acoustic startle stimulus. The cochlear root neurons (CRNs) are the first cells of the ASR circuit to receive cholinergic inputs from non-olivocochlear neurons of the ventral nucleus of the trapezoid body (VNTB) and subsequently decrease their neuronal activity in response to auditory prepulses. Yet, the contribution of the VNTB-CRNs pathway to the mediation of PPI has not been fully elucidated. In this study, we used the immunotoxin anti-choline acetyltransferase (ChAT)-saporin as well as electrolytic lesions of the medial olivocochlear bundle to selectively eliminate cholinergic VNTB neurons, and then assessed the ASR and PPI paradigms. Retrograde track-tracing experiments were conducted to precisely determine the site of lesioning VNTB neurons projecting to the CRNs. Additionally, the effects of VNTB lesions and the integrity of the auditory pathway were evaluated via auditory brain responses tests, ChAT- and FOS-immunohistochemistry. Consequently, we established three experimental groups: 1) intact control rats (non-lesioned), 2) rats with bilateral lesions of the olivocochlear bundle (OCB-lesioned), and 3) rats with bilateral immunolesions affecting both the olivocochlear bundle and the VNTB (OCB/VNTB-lesioned). All experimental groups underwent ASR and PPI tests at several interstimulus intervals before the lesion and 7, 14, and 21 days after it. Our results show that the ASR amplitude remained unaffected both before and after the lesion across all experimental groups, suggesting that the VNTB does not contribute to the ASR. The%PPI increased across the time points of evaluation in the control and OCB-lesioned groups but not in the OCB/VNTB-lesioned group. At the ISI of 50 ms, the OCB-lesioned group exhibited a significant increase in%PPI (p < 0.01), which did not occur in the OCB/VNTB-lesioned group. Therefore, the ablation of cholinergic non-olivocochlear neurons in the OCB/VNTB-lesioned group suggests that these neurons contribute to the mediation of auditory PPI at the 50 ms ISI through their cholinergic projections to CRNs. Our study strongly reinforces the notion that auditory PPI encompasses a complex mechanism of top-down cholinergic modulation, effectively attenuating the ASR across different interstimulus intervals within multiple pathways.

Nuclear maturation kinetics and in vitro fertilization of immature bovine oocytes injected into pre-ovulatory follicles.

The maturation kinetics and in vitro fertilization of immature bovine oocytes injected by the intra-follicular oocyte injection (IFOT) technique into pre-ovulatory follicles of previously synchronized cows were evaluated. In Experiment 1, grade I, II and III cumulus-oocyte complexes (COCs) were randomly distributed to one of three Groups: Matvitro22 (COCs matured in vitro for 22 h), MatFol20 and MatFol28 (COCs matured in vivo after being injected into a pre-ovulatory follicle of previously synchronized cows for 19.8 ± 0.1 h and 28.3 ± 0.1 h, respectively). Cows received 12.5 mg of LH (Lutropin, Bioniche, Canada) at the time of IFOT in the MatFol20 Group or 10 h after IFOT in the MatFol28 Group. MatFol20 and MatFol28 COCs were aspirated approximately 20 h after the LH injection for nuclear maturation kinetics and recovery rate assessment. In Experiment 2, grade I, II, and III COCs were randomly distributed into two Groups: Matvitro22 Group, COCs were matured and fertilized in vitro, and MatFol20 Group, COCs were matured as in the MatFol20 Group in Experiment 1, but COCs were fertilized in vitro. Putative zygotes were classified as fertilized, unfertilized or polyspermic. In Experiment 1, the recovery rate was lower (P < 0.001) in the MatFol20 Group (52.9%, 91/172) compared with MatFol28 (72.9%, 113/155). Rate of oocytes in germinal vesicle stage, metaphase I, anaphase I and telophase I were similar among Groups. However, oocytes matured in vivo for 28.3 h had lower rate of metaphase II (P = 0.001) and greater rates of degenerated (P = 0.001) and parthenogenetically activated (P = 0.001) oocytes. In experiment 2, the rates of polyspermy and degenerated were similar between Groups. However, the rate of fertilized oocytes was greater (P = 0.05) in oocytes in the MatFol20 Group. It is concluded that oocyte in vivo maturation for 19.8 h after IFOT does not compromise the nuclear maturation kinetics and increases in vitro fertilization rates. However, the extra 10 h of intra-follicular incubation time decreased oocyte viability.

Lubrication of chocolate during oral processing.

The structure of chocolate is drastically transformed during oral processing from a composite solid to an oil/water fluid emulsion. Using two commercial dark chocolates varying in cocoa solids content, this study develops a method to identify the factors that govern lubrication in molten chocolate and saliva's contribution to lubrication following oral processing. In addition to chocolate and its individual components, simulated boluses (molten chocolate and phosphate buffered saline), in vitro boluses (molten chocolate and whole human saliva) and ex vivo boluses (chocolate expectorated after chewing till the point of swallow) were tested. The results reveal that the lubrication of molten chocolate is strongly influenced by the presence of solid sugar particles and cocoa solids. The entrainment of particles into the contact zone between the interacting surfaces reduces friction such that the maximum friction coefficient measured for chocolate boluses is much lower than those for single-phase Newtonian fluids. The addition of whole human saliva or a substitute aqueous phase (PBS) to molten chocolate dissolves sugar and decreases the viscosity of molten chocolate so that thinner films are achieved. However, saliva is more lubricating than PBS, which results in lower friction coefficients for chocolate-saliva mixtures when compared to chocolate-PBS mixtures. A comparison of ex vivo and in vitro boluses also suggests that the quantity of saliva added and uniformity of mixing during oral processing affect bolus structure, which leads to differences in measured friction. It is hypothesized that inhomogeneous mixing in the mouth introduces large air bubbles and regions of non-emulsified fat into the ex vivo boluses, which enhance wetting and lubrication.

Aromaterapia: da gênese a atualidade / Aromatherapy: from genesis to today

Considerando que a Aromaterapia vem ao longo do tempo se consolidando como prática de grande relevância no tratamento de infecções e outras doenças do homem, decidiu-se produzir um levantamento exploratório bibliográfico desde sua origem até os dias atuais, com o intuito de acentuar cada vez mais a curiosidade e o conhecimento sobre essa arte e ciência milenar, que se apoia no uso racional dos óleos essenciais.

Over time, Aromatherapy has consolidated itself as a traditional and important practice for the treatment of infections and diseases of men. The purpose of the study is to conduct an exploratory literature review that encompasses its origin and its present-day scenario. Our intention is to call attention to the curiosity and knowledge that exists about this ancient art and science, which is based on the rational use of essential oils.