Neural and Pavlovian influences on immunity

The traditional view that the nervous and immune systems are functionally independent (aside from general stress effects and autoimmune disorders of the nervous system) is being challenged by a new view that the nervous system regulates the activity of the immune system. If this is true, it should be possible to change the activity of the immune system by means of Pavlovian conditioning, just as it is possible to condition other physiological events influenced by the autonomic nervous system or neuroendocrine substances. Evidence for autonomic and neuroendocrine modulation of immune activity is briefly reviewed; and, the various studies reporting conditioned immune effects, the physiological mechanisms most likely involved, and their possible significance are discussed.     

gamma-Aminobutyric acid in peripheral tissues

Significant amounts of gamma-aminobutyric acid (GABA), an endogenous amino acid, are present in mammalian peripheral tissues. This finding led to the suggestion that GABA may act as a neurotransmitter in the peripheral nervous system as it does in the central nervous system. This review deals with recent identification of GABA in the autonomic nervous system and the possible functional role of GABA in neuronal and non-neuronal tissues. The identification of GABA in the autonomic nervous system has paved the way for new approaches in pharmacological investigations.     

Neurobiological effects of microwave exposure: a review focused on morphological findings in experimental animals

The possible risk of electromagnetic radiation (EMR) for nervous system is regularly published from the middle of 20th century. Numbers of neurobiological studies demonstrate that various EMR frequencies induce changes in nervous tissue of experimental animals but the evidence for health effect of EMR to the nervous system remains uncertain. To solve the fundamental questions about possible health hazard of modern technologies, the main producers of EMR, further intensive experimental studies on animals are needed. This review, focused on morphological findings achieved in various experimental animals, demonstrates that blood-brain barrier is the most studied morpho-functional unit of CNS in experiments with EMR. The morphological findings in experimental animals, in many cases controversial, put some evidence on nervous tissue structural damage after the EMR exposure. In spite of numerous literary data a wide range of contemporary neuro-morphological methods waits to be utilized in the EMR experimental paradigm. Using these methods could play an important role in answering the question about possible adverse effects of microwaves on nervous system.     

The potential use of cultured cells to detect non-neuronal targets of neuropeptide action

Although many studies have described the localization and possible neuromodulatory role of neuropeptides little attempt has been made to determine whether glial cells are possible targets of neuropeptides' actions. The use of primary cell cultures derived from neonatal rat central and peripheral nervous system may provide a means of assaying for such effects and gaining a better understanding of glial cells' roles in nervous system function.     

Modulation of motor functions involving central dopaminergic system by L-histidine

There exists a possibility of interactions of histaminergic system with other neurotransmitters and their receptors in the central nervous system. Experimental evidences suggest a possible inhibitory influence of histaminergic system on the dopaminergic system. To elucidate the possible interaction between the histaminergic and dopaminergic pathways, we devised a strategy to study their effects on locomotor function and stereotypy behaviour. We investigated the effect of L-histidine, the precursor of histamine, on apomorphine-induced stereotypy and perphenazine-induced catalepsy. Histidine antagonised apomorphine-induced stereotypy. This inhibitory effect of histidine was abolished by both H1- and H2-receptor antagonists, chlorpheniramine and cimetidine, respectively. Perphenazine-induced catalepsy was potentiated by histidine and this effect was inhibited by chlorpheniramine alone but not by cimetidine. These results confirm a possible histamine-dopamine interaction in the modulation of motor functions by the central nervous system.     

Architectonics of the central nervous system of Acoela,Platyhelminthes, and Rotifera

Based on the literature and own data, consecutive stages of development of the central nervous system (CNS) in the lower Bilateria are considered-separation of brain from parenchyma, formation of its own envelopes, and development of the trunk and orthogonal nervous system. Results of histochemical (cholinergic and catecholaminergic) and immunocytochemical (5-HT-and FMRF-amid immunoreactive) studies of the CNS in representatives of Acoela, free living and parasitizing Platyhelminthes and Rotifera are considered. The comparative analysis makes it possible to describe development and complication of the initially primitive Bilateria pleux nervous system. A special attention will be paid to the Acoela phylogenesis, based on molecular-biology data and results of study of their nervous system.     

Morphology of the bourgueticrinid and isocrinid aboral nervous system and its possible phylogenetic implications (Echinodermata, Crinoidea)

Bohn, J. M. & Heinzeller, T. 1999. Morphology of the bourgueticrinid and isocrinid aboral nervous system and its possible phylogenetic implications (Echinodermata, Crinoidea). — Acta Zoologica (Stockholm) 80: 241-249.
On the basis of semithin serial sections the aboral nervous system within the calyx of five bourgueticrinid and one isocrinid species was reconstructed using the computer programm NIH Image. The aboral nervous system of all bourgueticrinids belongs to a common type which is proposed to be called ' Bathycrinus -type' (B-type), that differs from the ' Isocrinus -type' (I-type). The morphology of the B-type and the I-type are described and differences are discussed. Together with the B-type there are now six aboral nervous system types well established and the consequences regarding phylogeny are discussed. Conclusions: 1) The morphology of the aboral nervous system may be a useful tool for the clarification of relationships between crinoid groups; 2) All known aboral nervous system types can be derived from the I-type, which seems to be the most primitive one; 3) The B-type aboral nervous system is probably a synapomorphic feature charac-terizing a monophyletic group within the Bourgueticrinida.     

Assay and regional distribution of a soluble protein characteristic of the nervous system

Abstract An assay, based on complement fixation, was described for the S-100 protein, a protein characteristic of the nervous system. It was found to be distributed in all parts of the nervous system both peripherally and centrally. It was not possible to deduce from the distribution the localization in cell type, but in human brain the concentration in each of twenty-six areas was consistent from brain to brain.     

Architectonics of the central nervous system in Acoela, Plathelminthes, and Rotifera

Based on the literature and own data, consecutive stages of development of the central nervous system (CNS) in the lower Bilateria are considered - separation of brain from parenchyma, formation of its own envelopes, and development of the stem and orthogonal nervous system. Results of histochemical (cholinergic and catecholaminergic) and immunocytochemical (5-HT- and FMRFamid immunoreactive) studies of the CNS in representatives of Acoela, free living and parasitizing Plathelminthes and Rotifera are considered. The comparative analysis makes it possible to describe development and complication of the initially primitive Bilateria plexus nervous system. A special attention will be paid to the Acoela phylogenesis, based on molecular-biology data and results of study of their nervous system.     

FIXATION OF NEURAL TISSUES FOR ELECTRON MICROSCOPY BY PERFUSION WITH SOLUTIONS OF OSMIUM TETROXIDE

This paper describes in detail a method for obtaining nearly uniform fixation of the nervous system by vascular perfusion with solutions of osmium tetroxide. Criteria are given for evaluating the degree of success achieved in the preservation of all the cellular components of the nervous system. The method permits analysis of the structural relations between cells at the electron microscopic level to an extent that has not been possible heretofore.     

Enteric neurons show a primary cilium

The primary cilium is a non‐motile cilium whose structure is 9+0. It is involved in co‐ordinating cellular signal transduction pathways, developmental processes and tissue homeostasis. Defects in the structure or function of the primary cilium underlie numerous human diseases, collectively termed ciliopathies. The presence of single cilia in the central nervous system (CNS) is well documented, including some choroid plexus cells, neural stem cells, neurons and astrocytes, but the presence of primary cilia in differentiated neurons of the enteric nervous system (ENS) has not yet been described in mammals to the best of our knowledge. The enteric nervous system closely resembles the central nervous system. In fact, the ultrastructure of the ENS is more similar to the CNS ultrastructure than to the rest of the peripheral nervous system. This research work describes for the first time the ultrastructural characteristics of the single cilium in neurons of rat duodenum myenteric plexus, and reviews the cilium function in the CNS to propose the possible role of cilia in the ENS cells.     

Evolution of eumetazoan nervous systems: insights from cnidarians

Cnidarians, the sister group to bilaterians, have a simple diffuse nervous system. This morphological simplicity and their phylogenetic position make them a crucial group in the study of the evolution of the nervous system. The development of their nervous systems is of particular interest, as by uncovering the genetic programme that underlies it, and comparing it with the bilaterian developmental programme, it is possible to make assumptions about the genes and processes involved in the development of ancestral nervous systems. Recent advances in sequencing methods, genetic interference techniques and transgenic technology have enabled us to get a first glimpse into the molecular network underlying the development of a cnidarian nervous system—in particular the nervous system of the anthozoan Nematostella vectensis. It appears that much of the genetic network of the nervous system development is partly conserved between cnidarians and bilaterians, with Wnt and bone morphogenetic protein (BMP) signalling, and Sox genes playing a crucial part in the differentiation of neurons. However, cnidarians possess some specific characteristics, and further studies are necessary to elucidate the full regulatory network. The work on cnidarian neurogenesis further accentuates the need to study non-model organisms in order to gain insights into processes that shaped present-day lineages during the course of evolution.     

The effects of ionic lanthanum and hypertonic physiological salines on the nervous systems of larval and adult stick insects.

The effects of the electron-opaque tracer ionic lanthanum in various concentrations and of hyperosmotic physiological salines on the nervous system of the stick insect, Carausius morosus, have been studied. Examination of the experimentally treated tissues revealed that the diffusion barrier to the exogenous tracer was maintained in all cases in the adult central and peripheral nervous systems, but not in the hatchling. When hatchling nervous tissues were incubated in 50 mM ionic lanthanum in phyerosmotic physiological saline, the tracer readily infiltrated all the extracellular spaces between axons and glia of all components of the nervous system examined. No difference was noted in this regard between fed and unfed hatchlings, Further, in all cases examined of adults and hatchlings, lanthanum readily surrounded those neurosecretory axons which are found in the neutral lamella, or extracellular nerve sheath, of the insect. The possible meanings of these variations in hatchling and adult nervous systems and in the accessibility of different elements of the nervous system to exogenous ionic lanthanum are discussed.     

Neuromorphologic aspects of experimental herpetic infection

At intracerebral, intracutaneous, intracorneal and intraneural ways of infection with herpes simplex to mice and rabbits it has been stated immunomorphologically and electron microscopically that reproduction of the virus has been observed in various cells of the nervous system and accompanied with appearance of certain dystrophic changes in them. Reproductivity of the disease, duration of the incubation period, spread of the pathological process, successiveness of the lesion in the nervous system structures are determined by neurotropism of the strain and by the infection variant. The subclinical course of the infection does not exclude a productive reproduction of the virus in sensitive cells and corresponding morphologic equivalent. Inflammatory-dystrophic changes in the nervous tissue are always wider than the virus fixation zone. Reveal of the virus antigen and viral particles usually overtakes the appearance of infective-allergic reactions. The electron microscopic investigations prove that a whole cycle of the virus reproduction in the nervous system cells is possible. A predominant reveal of the viral particles in the axoplasma of the nervous fibers emphasizes the importance of the axonal way for penetration of the virus into the nervous system. The complex experimental-morphological investigation is an adequate model for studying pathogenesis and pathomorphology of the herpetic infection.     

Nerve growth factor and neuronal cell death

The regulation of neuronal cell death by the neuronotrophic factor, nerve growth factor (NGF), has been described during neural development and following injury to the nervous system. Also, reduced NGF activity has been reported for the aged NGF-responsive neurons of the sympathetic nervous system and cholinergic regions of the central nervous system (CNS) in aged rodents and man. Although there is some knowledge of the molecular structure of the NGF and its receptor, less is known as to the mechanism of action of NGF. Here, a possible role for NGF in the regulation of oxidant--antioxidant balance is discussed as part of a molecular explanation for the known effects of NGF on neuronal survival during development, after injury, and in the aged CNS.     

Localisation of histamine-immunoreactivity in specific neurones of the gastropod CNS including a cell which has been identified as histaminergic

Immunohistochemical procedures revealed the occurrence of histamine-like immunoreactivity in specific neurones in the gastropod nervous system. Positive staining was also associated with a characterised neurone known from previous biochemical studies to contain histamine. The proof of the restriction of histamine to specific neurones and the availability of a suitable antiserum to localise the amine makes it possible to examine the role of the compound in different nervous systems.     

MicroRNA与神经系统重大疾病

目前有研究证实microRNA参与了神经系统生长发育和生理功能的调控,它也与可塑性障碍性疾病、神经系统退行性疾病、神经系统肿瘤、脑血管疾病等重大疾病的发生发展相关．随着microRNA研究领域的发展,一些重大神经系统疾病的相关发病机制将有可能被阐释．     

The supramedullary cells of the teleost Coris julis (L.): a noradrenergic neuronal system

This study, carried out on Coris julis (Labridae), is a contribution to the immunocytochemical characterization of fish supramedullary neurons. The significance of these giant cells has been debated since the beginning of the twentieth century. Our research provides the first evidence for a noradrenergic feature of this neuronal system. The possible role of supramedullary neurons as components of the autonomic nervous system is discussed. Moreover, the present results, taken together with our previous studies, surmise that this the first known case of colocalization of a neuropeptide (gastrin/CCK-like) and noradrenaline in the nervous system of teleosts.     

Central nervous system involvement in experimental Trypanosomiasis cruzi.

A review of the available literature on central nervous system involvement in experimental trypanosomiasis cruzi is undertaken. From a critical analysis of 26 works on experimental infections with Trypanosoma cruzi (23 on the acute phase, 2 on the chronic phase, and one describing sequentially both phases), all supported by neuropathologic studies, it can be concluded that: 1) central nervous system involvement during the acute phase, in the form of encephalitis in multiple foci, with variable intensity of the parasitism and inflammatory changes, is frequent and well documented; 2) in animals with more severe central nervous system involvement death occurs as a result of the brain lesions or acute chagasic myocarditis, the latter being always present; 3) in animals with more discrete brain involvement death during the acute phase is due to complications not related to the nervous system, among which congestive heart failure secondary to acute chagasic myocarditis, a condition that is always present, regardless of whether or not the central nervous system is infected; 4) it is possible that in surviving animals that had mild encephalitis the inflammatory changes from the acute phase usually regress as the infection progress to the chronic phase.