Comparative aspects of the area postrema: fine-structural considerations help to determine its function

The area postrema is a circumventricular organ of the fourth ventricle of the mammalian brain. Although there are distinct gross anatomical differences in the appearance of this organ between "lower" mammals such as rodents and lagomorphs and "higher" mammals such as carnivores and primates, its fine structure is remarkably similar in all species studied. There are many suggestions in the literature for a specific function for this area of the brain, ranging from its being a chemoreceptive trigger zone for the emetic response to its being a regulatory nucleus for the sleep cycle. The present report describes some comparative studies on the ultrastructure of this organ. This information is discussed in relation to what is known about the neurochemistry of the area postrema and its connections with other brain regions and visceral structures. A suggestion is offered that our current knowledge of the area postrema is consistent with its performing many of its proposed functions in the context of a regulatory ("fine-tuning") center for many autonomic functions.     

Synaptosomes Still Viable after 25 Years of Superfusion

Superfused synaptosomes have been utilized in studies of neurotransmitter release during 25 years. This review summarizes the aspects of neurotransmission that have been and could be successfully investigated with this technique. The major aim of the article is to draw attention on the versatility of superfused synaptosomes and to suggest how the system could be exploited in clarifying several aspects of synaptic neurochemistry including neurotransmitter transport, receptor localization, receptor-receptor interactions, functional aspects of multi-sited receptor complexes, receptor heterogeneity and mechanisms of neurotransmitter exocytosis-endocytosis.     

The neurochemical basis of human cortical auditory processing: combining proton magnetic resonance spectroscopy and magnetoencephalography

Background  

A combination of magnetoencephalography and proton magnetic resonance spectroscopy was used to correlate the electrophysiology of rapid auditory processing and the neurochemistry of the auditory cortex in 15 healthy adults. To assess rapid auditory processing in the left auditory cortex, the amplitude and decrement of the N1m peak, the major component of the late auditory evoked response, were measured during rapidly successive presentation of acoustic stimuli. We tested the hypothesis that: (i) the amplitude of the N1m response and (ii) its decrement during rapid stimulation are associated with the cortical neurochemistry as determined by proton magnetic resonance spectroscopy.     

Undernutrition and the development of brain neurotransmitter systems

While there are homeostatic mechanisms to protect the brain against wide fluctuations in the availability of essential nutrients, food deprivation is known to influence brain neurochemistry. Given the growing problem of infant undernutrition and the fact that the developing nervous system appears to be especially vulnerable to this type of insult, numerous studies have been conducted to define the relationship between nutritional factors and cellular growth and maturation in the brain. The data suggest that the development of both neural and nonneural elements are significantly affected by undernutrition. This includes processes and substances important for neurotransmission such as transmitter synthesis, degradation and receptor sites. Because many neuropsychiatric conditions can be traced to dysfunctions in synaptic neurochemistry, it is possible that some of the central nervous system abnormalities which result from childhood undernutrition may be a consequence of a modification in synaptic biochemistry. The present report reviews data relating to this issue with the aim of assessing its relevance to developmental neurobiology.     

Cocaine withdrawal causes delayed dysregulation of stress genes in the hippocampus

Relapse, even following an extended period of withdrawal, is a major challenge in substance abuse management. Delayed neurobiological effects of the drug during prolonged withdrawal likely contribute to sustained vulnerability to relapse. Stress is a major trigger of relapse, and the hippocampus regulates the magnitude and duration of stress responses. Recent work has implicated hippocampal plasticity in various aspects of substance abuse. We asked whether changes in stress regulatory mechanisms in the hippocampus may participate in the neuroadaptations that occur during prolonged withdrawal. We therefore examined changes in the rat stress system during the course of withdrawal from extended daily access (5-hours) of cocaine self-administration, an animal model of addiction. Tissue was collected at 1, 14 and 28 days of withdrawal. Plasma corticosterone levels were determined and corticosteroid receptors (GR, MR, MR/GR mRNA ratios) and expression of other stress-related molecules (HSP90AA1 and HSP90AB1 mRNA) were measured in hippocampal subfields using in situ hybridization. Results showed a delayed emergence of dysregulation of stress genes in the posterior hippocampus following 28 days of cocaine withdrawal. This included increased GR mRNA in DG and CA3, increased MR and HSP90AA1 mRNA in DG, and decreased MR/GR mRNA ratio in DG and CA1. Corticosterone levels progressively decreased during the course of withdrawal, were normalized following 28 days of withdrawal, and were correlated negatively with GR and positively with MR/GR mRNA ratio in DG. These results suggest a role for the posterior hippocampus in the neuroadaptations that occur during prolonged withdrawal, and point to a signaling partner of GR, HSP90AA1, as a novel dysregulated target during cocaine withdrawal. These delayed neurobiological effects of extended cocaine exposure likely contribute to sustained vulnerability to relapse.     

A History of the Origin and Development of Japanese Society for Neurochemistry: International Cooperation to Overcome Dementia and Mental Illness

“Neurochemistry” in Japan was established by intensive cooperation between psychiatrists and their collaborators, biochemists, who have sought to investigate the etiology of mental illness to establish treatments. It was a completely different direction from the flow of modern biochemistry that was born using microorganisms or eukaryotic cells as research materials. Neurochemists aimed to elucidate the physiological or pathological functions of the brain through chemical analysis of the morphologically and functionally unique complexity and characteristics of brain. I here describe some of the origin and history of neurochemistry in Japan how researchers estabIished Japanese Society for Neurochemistry in1958 Yasuzo Tsukada as a president in collaboration with Isamu Sano, Genkichiro Takagaki and Masanori Kurokawa. The formation of research groups with the support of MEXT played a major role in promoting neurochemistry. Many international conferences held in Japan promoted the activity of neurochemistry: The International Society of Physiology (Tokyo) in 1965, and the Japan-US Neurochemistry Conference (Oiso) in 1965, and in 1967 the International Conference on Biochemistry (Tokyo). These meetings offered excitements to younger researchers by close interaction with the world top class researchers. Government established Brain Research Institutes in several national universities. The Asia–Pacific Society for Neurochemistry (APSN) was established in 1991 subsequent to an initiative by JSN. APSN presidents: Yasuzo Tsukada, Kazuhiro Ikenaka, and Akio Wanaka contributed to promote neurochemistry. The 4th ISN meeting was organized at Tokyo (Yasuzo Tsukada, president) in 1973 and the 15th ISN meeting at Kyoto (Kinya Kuriyama, president) in 1995. Kunihiko Suzuki and Kazuhiro Ikenaka as ISN Presidents greatly contributed in promoting the activity of ISN.

     

Proton Nuclear Magnetic Resonance Spectroscopy of Rabbit Brain Homogenate

Abstract: Proton nuclear magnetic resonance (¹H NMR) spectroscopy in conjunction with the inversion-recovery spin-echo pulse sequence was used to obtain spectra from rabbit brain homogenate. The instrumental parameters required for the acquisition of spectra together with the assignment of major peaks are given. The rationale and prospectus for the use of this technique for the study of neurochemistry is outlined.     

Targeting imidazoline site on monoamine oxidase B through molecular docking simulations

Monoamine oxidase (MAO) is an enzyme of major importance in neurochemistry, because it catalyzes the inactivation pathway for the catecholamine neurotransmitters, noradrenaline, adrenaline and dopamine. In the last decade it was demonstrated that imidazoline derivatives were able to inhibit MAO activity. Furthermore, crystallographic studies identified the imidazoline-binding domain on monoamine oxidase B (MAO-B), which opens the possibility of molecular docking studies focused on this binding site. The goal of the present study is to identify new potential inhibitors for MAO-B. In addition, we are also interested in establishing a fast and reliable computation methodology to pave the way for future molecular docking simulations focused on the imidazoline-binding site of this enzyme. We used the program 'molegro virtual docker' (MVD) in all simulations described here. All results indicate that simplex evolution algorithm is able to succesfully simulate the protein-ligand interactions for MAO-B. In addition, a scoring function implemented in the program MVD presents high correlation coefficient with experimental activity of MAO-B inhibitors. Taken together, our results identified a new family of potential MAO-B inhibitors and mapped important residues for intermolecular interactions between this enzyme and ligands.     

The History of Neurochemistry as Revealed by the Journal of Neurochemistry

Abstract: Analyses of samples of articles in the Journal of Neurochemistry between 1956 (the year of its foundation) and 1990 were used to obtain numerical indices of the history of neurochemistry. Data suggest that the acceleration of neurochemical research did not merely reflect the increase of biochemical research in general and that it involved progressive decreases and increases of interest in major constituents and transmitters, respectively, as indicated by both numbers and citations of papers. Papers on all classes of transmitters increased steadily and in the order of amines > amino acids, acetylcholine > peptides. Within the field of brain metabolism, papers on energy metabolism decreased markedly. Use of techniques other than those of biochemistry/neurochemistry altered strikingly with decreases of histological, electrophysiological, and pharmacological methods and increases of chemical, immunological, and tissue culture methods. Citations by neuroscience core journals between 1975 and 1988 suggest that the relative prominence of neurochemistry within neuroscience has remained constant. Analyses indicate that the influence of the U.S.A. relative to that of other regions has remained fairly steady between 1956 and 1990, but that number of papers from the U.K. has declined, whereas the influences of Western Europe and other areas appear to have recently increased substantially. Sociological changes have been the virtual disappearance of single-author papers, an increase of multiauthorship (>3), and a recent striking increase of assertive sentence titles.     

Toll样受体在肝脏疾病中的功能

Toll样受体(Toll-like receptors,TLR)是一类可以识别病原体并迅速启动天然免疫反应的跨膜蛋白,它们也可以调节机体的获得性免疫及组织的炎症反应,是机体感知、抵御及清除病原体的关键分子。近来发现TLR在多种肝脏疾病的发生、发展及恢复过程中起着重要的调节作用,这方面的研究为许多慢性肝病的治疗提供了新的线索。该文综述了TLR在酒精性肝病、脂肪肝、病毒性肝炎、肝硬化以及肝细胞癌的病理生理学中的作用,展望了将来需重点研究的问题。     

Peptide neuroregulators: the opioid system as a model

Aaron Lerner's work provides a stunning set of examples of substances that help to transmit information in the brain and body. His characterization of alpha-MSH and melatonin and his sparking of interest in the further discovery of previously unknown substances have been of inestimable value for the field of neurobiology. Efforts such as those that Lerner undertook so successfully in the field of investigative dermatology now constitute a major research thrust in the field of behavioral neurochemistry and are directly related to advances in psychiatry and neurology. This review considers aspects of research on the neuropeptides, with particular attention to the endogenous opioid (morphine-like) peptides that are active on neural tissue. Neuropeptide research can be categorized broadly as efforts to discover and characterize new families and classes of active agents, investigations of their genetic and molecular processing, and studies of their relationships to behavior in animals and human beings. This review selectively considers some key research questions and strategies that arise from such research.     

Crustacean neuroendocrine systems and their signaling agents

Decapod crustaceans have long served as important models for the study of neuroendocrine signaling. For example, the process of neurosecretion was first formally demonstrated by using a member of this order. In this review, the major decapod neuroendocrine organs are described, as are their phylogenetic conservation and neurochemistry. In addition, recent advances in crustacean neurohormone discovery and tissue mapping are discussed, as are several recent advances in our understanding of hormonal control in this group of animals.     

Review. Psychological and neural mechanisms of relapse

Relapse, the resumption of drug taking after periods of abstinence, remains the major problem for the treatment of addiction. Even when drugs are unavailable for long periods or when users are successful in curbing their drug use for extended periods, individuals remain vulnerable to events that precipitate relapse. Behavioural studies in humans and laboratory animals show that drug-related stimuli, drugs themselves and stressors are powerful events for the precipitation of relapse. Molecular, neurochemical and anatomical studies have identified lasting neural changes that arise from mere exposure to drugs and other enduring changes that arise from learning about the relationship between drug-related stimuli and drug effects. Chronic drug exposure increases sensitivity of some systems of the brain to the effects of drugs and stressful events. These changes, combined with those underlying conditioning and learning, perpetuate vulnerability to drug-related stimuli. Circuits of the brain involved are those of the mesocorticolimbic dopaminergic system and its glutamatergic connections, and the corticotropin-releasing factor and noradrenergic systems of the limbic brain. This paper reviews advances in our understanding of how these systems mediate the effects of events that precipitate relapse and of how lasting changes in these systems can perpetuate vulnerability to relapse.     

O. V. Palladin--patriarch of neurochemical science (on the 120th birthday of academician Oleksandr Volodymyrovych Palladin)

The paper is dedicated to Academician Oleksandr Volodymyrovych Palladin (1895-1972), a founder of neurochemical school in Ukraine. The problem of biochemistry of the nervous system has been developed in Ukraine since the 20's of the 20th century. Theoretical principles and prospects of development of the basic trends in neurochemistry were stated for the first time in the paper by O. V. Palladin--the first work in biochemistry of the nervous system in Ukraine--"Biochemistry of the Brain and Psychochemistry", published in the journal "Nauka v Ukraine" ("Science in Ukraine") in 1922. Researches in neurochemistry have been carried out systematically since 1925 at the Ukrainian Biochemical Institute founded and headed by O. V. Palladin (O. V. Palladin Institute of Biochemistry, now). During the following period of half a century O.V.Palladin and his disciples made original works in the field of chemical topography of the nervous system, functional neurochemistry, in particular, in the field of protein and nitrous, lipid, nucleic metabolism, transmembrane transport of ions and metabolites, etc. Results of long-term investigations were reported at numerous international physiological and biochemical congresses, All-Union and Ukrainian biochemical conferences, seminars and have acquired the world fame. O. V. Palladin's great deserts in development of biochemistry of the nervous system were recognized and he was proclaimed a "patriarch" of the world neurochemistry at the first congress of the International Neurochemical Society in Strassburg (1967) and awarded a Gold Medal--one of the four delivered at the Second Congress of this Society in Milan (1969).     

Neurobiology of parasitic flatworms: how much "neuro" in the biology?

The nervous systems in the parasitic Platyhelminthes have generally been considered to be degenerate and of marginal significance, but recent studies have shown these systems to be more significant in the biology of these animals than formerly believed. There are many similarities in the construction and apparent neurochemistry of the nervous systems in the parasitic forms as well as in the free-living Turbellaria. In all forms there appears to be a large neurohormonal component. Though the nervous system appears to be important for many aspects of parasitic flatworm biology, little direct or specific information about the physiology of these systems is yet available.     

Participation of women in neurochemistry societies

Women have made important scientific contributions to the field of neurochemistry, and they have also been leaders in neurochemical societies throughout the world. Here I discuss women's involvement and leadership in six neurochemistry societies: American Society for Neurochemistry, Argentine Society for Neurochemistry, International Society for Neurochemistry, European Society for Neurochemistry, Japanese Society for Neurochemistry, and Asian-Pacific Society for Neurochemistry. The number of women who have been active in these societies and the level of their activity vary considerably. Neurochemical societies in the Western hemisphere, i.e., the American and the Argentine Society for Neurochemistry, have much greater numbers of women who have held office, been on council, or engaged in other leadership activities than in the rest of the world. The limited participation of women in the Japanese Neurochemistry Society relates to Japanese cultural views and was not unexpected. However, the relatively few women leaders in the International Society for Neurochemistry was a surprise. The European Society had a somewhat better record of female participation than did the International Society. The reasons for these differences are partly cultural, but factors related to when each society was formed, how it is organized, and how elections are structured undoubtedly play a role. Further analysis of these observations would be of interest from a sociological and a women's studies point of view     

Application of adeno-associated viral vectors in behavioral research

Viral vectors afford the capability of genetically manipulating the expression of neurotransmitters, neuropeptides, hormones, and their receptors in specific brain sites of adult animals of any species. Hence, they are a powerful tool for investigating the neurochemistry underlying complex cognitive processes and behaviors. Here we discuss how the recombinant adeno-associated virus (rAAV) can be engineered for use in neurobehavioral studies, techniques for site-specific delivery of vector into the brain, characterization of expression profiles, and biosafety issues. Finally, we discuss issues of experimental design and interpretation of behavioral results in viral vector studies.     

Cultured neuroblastoma cells in biochemical studies

Neuroblastoma is a spontaneous tumour of animals and people. Tumour strains maintained as transplanted tumours and constant cell lines in suspension and monolayer cultures in vitro are obtained. The neuroblastoma cells are able to spontaneous and induced differentiation. The differentiated neuroblastoma cells have many specific properties of nature neurons and are a rather valuable object for solution of many problems in neurochemistry and general cell biology. It is neuroblastoma that has been used to show first the reversibility of neoplastic transformation and to carry out numerous studies to elucidate the mechanisms of cell differentiation. The neuroblastoma cell cultures are a convenient object for studying the ion channels and specifying the role of membrane lipids in their work.     

Neurochemistry and Behavior in Man

The distribution and functions of certain neurotransmitter substances seem to correlate with clinical, anatomical and physiological evidence about the mediation of normal and abnormal behaviors in man, though much remains to be learned. The biosynthetic and metabolic pathways, receptors and reuptake mechanisms, and relationships to cyclic nucleotides for several major neurotransmitters are characterized, as well as the specific actions of many behavior-modifying drugs employed clinically. Experimental systems, including nerve cells in culture, permit tests of molecular actions inferred from biochemical and neurophysiological analyses in intact brain. This selective review emphasizes advances in neurochemistry which provide a context for current and future research on neurological and psychiatric disorders encountered in clinical practice.     

Catecholamine Phenotyping: Clues to the Diagnosis, Treatment, and Pathophysiology of Neurogenetic Disorders

Abstract: One purpose of clinical neurochemistry has been to indicate "activities" of catecholamine systems, by assaying levels of the effector compounds or their metabolites in body fluids such as plasma, cerebrospinal fluid, urine, or microdialysate. This review discusses a new purpose: relating specific catecholaminergic phenotypes to neurogenetic disorders. Distinctive catecholamine patterns in several neurogenetic conditions reflect enzyme deficiencies as direct or indirect effects of gene mutations. These neurochemical patterns can provide potentially important clues to the diagnosis, treatment, and pathophysiology of neurogenetic disorders. Linking genetic abnormalities with molecular mechanisms and clinical manifestations of disease represents a useful new direction in clinical neurochemistry.