Protein synthesis is essential not only for consolidation but also for maintenance and post-retrieval reconsolidation of acrobatic motor skill in rats

It has been reported that consolidation of motor skill, a type of non-declarative memories, requires protein synthesis, as hippocampus-dependent declarative memory does. However, little is known about the importance of protein synthesis in maintenance and especially post-retrieval reconsolidation of acrobatic motor skill. Here, we show that protein synthesis is essential not only for the consolidation but also for the maintenance and reconsolidation of a rotarod-running skill. Intra-ventricle infusion of the protein synthesis inhibitor anisomycin 0 h but not 2 h post-training caused a severe deficit in the acquisition of the rotarod-running skill. Protein synthesis inhibition (PSI) also caused a deficit in the maintenance of the rotarod-running skill, as well-trained rats demonstrated a deficit in the rotarod-running performance upon treatment with anisomycin. Similarly, PSI impaired the post-retrieval reconsolidation of the rotarod-running skill: well-trained rats treated with anisomycin 0 h but not 0.5, 2 and 4 h after the task performance exhibited amnesia for the running skill later on. Interestingly, rats treated with anisomycin 6 and 12 h post-retrieval exhibited amnesia for the running skill. Thus, protein synthesis is essential not only for the consolidation but also for the maintenance and post-retrieval reconsolidation of rotarod-running acrobatic motor skill

Neuronal representation of working memory in the medial prefrontal cortex of rats

Working memory is a process for short-term active maintenance of information. Behavioral neurophysiological studies in monkeys have demonstrated that the dorsolateral prefrontal cortex (dlPFC) is a key cortical region for working memory. The medial prefrontal cortex (mPFC) in rats is a cortical area similar to the dlPFC in monkeys in terms of anatomical connections, and is also required for behavioral performance on working-memory tasks. However, it is still controversial regarding whether and how mPFC neurons encode working memory. In the present study, we trained rats on a two-choice spatial delayed alternation task in Y maze, a typical working memory task for rodents, and investigated neuronal activities in the mPFC when rats performed the task. Our results show that, (1) inactivation of the mPFC severely impaired the performance of rats on the task, consistent with previous studies showing the importance of the mPFC for working-memory tasks; (2) 93.7% mPFC cells (449 in 479) exhibited changes in spiking frequency that were temporally locked with the task events, some of which, including delay-related cells, were tuned by spatial information; (3) differential delay activities in individual mPFC cells appeared transiently and sequentially along the delay, especially during the early phase of the delay; (4) some mPFC cells showed no change in discharge frequency but exhibited differential synchronization in firing during the delay. The present results suggest that mPFC neurons in rats are involved in encoding working memory, via increasing firing frequency or synchronization

Dynamic analysis of flexible hoisting rope with time-varying length

The governing equations of flexible hoisting rope are developed employing Hamilton’s principle. Experiments are performed. It is found that the experimental data agree with the theoretical prediction very well. The results of simulation and experiment show that the flexible hoisting system dissipates energy during downward movement but gains energy during upward movement. Further, a passage through resonance in the hoisting system with periodic external excitation is analyzed. Due to the time-varying length of the hoisting rope the natural frequencies of the system vary slowly, and transient resonance may occur when one of frequencies coincides with the frequency of external excitation.Основні рівняння гнучкого підіймального тросу отримано застосуванням принципу Гамільтона. Проведено експерименти, результати яких добре узгоджуються з теоретичним передбаченням. Результати моделювання і експеримент показують, що гнучка підіймальна система розсіює енергію при спуску і накопичує енергію при підйомі. Далі досліджувався перехід гнучкої підіймальної системи через резонанс за умови періодичного зовнішнього збудження. Якщо довжина гнучкої підіймальної системи змінюється з часом, то власні частоти системи слабо змінюються і можуть спостерігатися перехідні резонанси, коли одна з частот співпадає з частотою зовнішнього збудження

1-Bromo-3,5-diphenyl­benzene

The title compound, C18H13Br, crystallizes with two crystallographically independent mol­ecules in the asymmetric unit. The C—Br bond lengths and the C—C bond lengths between the benzene rings are slightly different in the two mol­ecules. The dihedral angles between adjacent benzene rings are 26.85 (2) and 39.99 (2)° in one mol­ecule, and 29.90 (2) and 38.01 (2)° in the other. There are three types of inter­molecular C—H⋯π inter­actions in the crystal structure

2,4,6-Trimethyl-1,3,5-tris­(morpholino­meth­yl)benzene

In the title compound, C24H39N3O3, the H atoms of the methyl groups are disordered over two positions, with site-occupation factors fixed at 0.5. The three morpholino groups are arranged in an asymmetrical fashion with respect to the anchoring mesitylene ring and adopt chair conformations. Inter­molecular C—H⋯π inter­actions link the mol­ecules into a one-dimensional chain structure

A Relationship between vascular endothelial cell senescence and cardiovascular disease

The vascular endothelial cell (VEC) is a single layer of flat squamous epithelium covering the intima of the blood vessel. It constitutes a biological barrier to the blood vessel wall. It is not only a protective barrier but also a producer of some autocrine secretion. The substance is used to regulate homeostasis and vascular tone and has a variety of biological functions. VEC senescence can lead to vascular dysfunction, which is a major risk factor for cardiovascular system (CVS) and has a close relationship with cardiovascular disease (CVD). However, the mechanism of VEC senescence and the effects of VEC senescence on vascular function are not fully understood. This review summarizes the characteristics of VEC senescence and describes age-related CVD

Bis(3-meth­oxy-6-methyl-2-pyrid­yl) ether

In the mol­ecule of the title compound, C14H16N2O3, the dihedral angle between the pyridyl rings is 87.74 (3)°. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into infinite zigzag chains

2-Ferrocenyl-6-methyl­pyridin-3-ol

In the title compound, [Fe(C5H5)(C11H10NO)], the dihedral angle between the pyridyl and substituted cyclo­penta­dienyl rings is 20.4 (3)°. The H atoms of the methyl group are disordered over two positions; their site-occupation factors were fixed at 0.5. The crystal structure is stabilized by well defined inter­molecular O—H⋯N and C—H⋯O hydrogen bonds, leading to the formation of a two-dimensional network parallel to (101)