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The hypothalamo-hypophysial system of the lamprey, Lampetra fluviatilis L. II. The proximal neurosecretory contact region.

The proximal neurosecretory contact region (PNCR) of the lamprey, a homologue of the median eminence of tetrapods, was studied by light, fluorescence and electron microscopy. Paraldehyde fuchsin-positive neurosecretory fibers are seen mainly in the central part of the rostral subdivision of the PNCR. The Falck-Hillarp technique reveals a weak, mainly diffuse yellow-green fluorescence in the PNCR. The ultrastructure of the tanycyte layer of the PNCR is very similar to that in the neurohypophysis of the same species, although the funnel-shaped protrusions of the third ventricle in the rostral part of the PNCR are more frequent than in the neurophypophysis. Peptidergic A1 and A2 neurosecretory fibers are characterized by neurosecretory granules of 120-200 nm and 100-150 nm in diameter, respectively. Monoaminergic B type fibers contain granules 80-100 nm in diameter. Neurosecretory terminals and the vascular endfeet of tanycytes make contact with the basement membrane of the avascular connective tissue layer separating the PNCR from the hypophysial pars distalis. It is suggested that both peptide and monoamine neurohormones diffuse through the thick connective tissue septa into the underlying blood vessels which supply the pars distalis and thus affect the function of its glandular cells.

Animals↗

Immunocytochemical identification of alpha-endorphin-like material in neurones of the brain and corpus cardiacum of the blowfly, Calliphora vomitoria (Diptera).

A group of the 24-26 paraldehyde fuchsin-positive median neurosecretory cells (MNC) in the pars intercerebralis of the brain of the blowfly, Calliphora vomitoria, has shown immunoreactivity towards three different antibodies to alpha-endorphin, a peptide that corresponds to the amino acid sequence present between residues 61 and 76 of the precursor molecule, beta-lipotropin (beta-LPH). The immunoreactive material could be followed in axons within the median bundle, the tract through which neurosecretory material from the MNC is passed down to the corpus cardiacum (CC). The alpha-endorphin-immunoreactive material was observed leaving the CC in the cardiac-recurrent nerve, dorsal to the proventriculus, in the direction of the abdomen. The cells that contain the alpha-endorphin-like material are different from those of the MNC that contain insulin-, pancreatic polypeptide-, and gastrin/CCK-like peptides. This finding demonstrates the considerable complexity and peptidergic nature of the MNC and constitutes further evidence that morphinomimetic-like peptides are present in the nervous system of invertebrates.

Animals↗

Reinterpretation of the literature indicates differential sensitivities of long-sleep and short-sleep mice are not specific to alcohol.

This paper reviews the findings and conclusions of the literature pertinent to the Long-Sleep and Short-Sleep selectively-bred lines of mice and challenges the widely-held notion that the selective breeding program was successful in separating alleles for specific sensitivities to just alcohol. Rather, it is argued that these lines of mice were selected for differing activity of a more general process. Recent evidence, as well as reevaluated previous evidence, indicates that Long-Sleep mice are more sensitive to the soporific effects of three major classes of CNS depressants (alcohols, barbiturates, and benzodiazepines), as well as many other anesthesia-inducing compounds (adenosine, chloral hydrate, trichloroethanol, paraldehyde, nitrous oxide, enflurane, and isoflurane). Further, much evidence also supports the conclusion that most of these hypnotic-depressants and anesthetics could exert their soporific influence by a potentiation of GABA activity. The other characteristic of interest in this regard is susceptibility to convulsions. Short-Sleep mice have significantly lower thresholds to both flurothyl-induced and bicuculline-induced convulsions, as well as being more likely to suffer from paroxysms during ethanol withdrawal.

Animals↗

Immunohistochemical localization of gastrin-cholecystokinin-like material in the central nervous system of the migratory locust.

Brain, corpora cardiaca (CC)-corpora allata (CA) complex, suboesophageal ganglion, thoracic and abdominal ganglia of adults, larvae and embryos of Locusta migratoria have been immunohistochemically screened for gastrin cholecystokinin (CCK-8(s]-like material. In adult, numerous immunoreactive neurons and nerve fibres are located, with a marked symmetry, in various parts of the brain and throughout the ventral nerve cord. In the median part of the brain, cell bodies belonging neither to cellular type A1 nor A2 (following Victoria blue-paraldehyde fuchsin staining) are immunopositive; their processes terminate in the upper protocerebral neuropile. In lateral parts of the brain, external cell bodies send axons into CC and some up to CA, other internal have processes which terminate in the neuropile of the brain. Two of these latter cells react also with methionine-enkephalin antiserum. In the ventral nerve cord, in addition to numerous perikarya, immunoreactive arborizations terminate in the neuropile or in close association with the sheath, at the dorsal part of all ganglia. This CCK-8(s) distribution pattern is observed only at the two last larval instars, but is precociously detected in the abdominal nerve cord of embryos, one day before hatching.

Animals↗

The microanatomy and fine structure of the rostellum of Hymenolepis diminuta.

The microanatomic arrangement of the muscular, nervous, and excretory systems as well as the organization of the tegument are described for the rostellum of Hymenolepis diminuta. An inner circular and an outer longitudinal layer of muscle comprise the rostellar capsule, delimiting the rostellum from the scolex proper. A similar muscular arrangement surrounds an apical invagination of the rostellar tegument, the anterior canal. Elements of the excretory and nervous systems enter the rostellum basally through a discontinuous region of the capsule. Although excretory canals extend into the rostellum, flame cells and their associated collecting ducts are absent. The rostellar nervous system is comprised of a single bilateral pair of ganglia, which provide motor innervation of the anterior canal, and the circular muscles of the rostellar capsule; it also receives dendrites from apical uniciliate sensory receptors. The tegument lining the anterior canal and covering the apical rostellum is syncytial and continuous with the tegument of the scolex proper. Twelve to 15 cytons are radially arranged around the anterior canal. They stain selectively with paraldehyde-fuchsin between days 3 and 35 postinfection, but are clearly tegumental, not neurosecretory elements. The appearance of ovoid granules in the rostellar tegumentary cytons coincides with the onset of fuchsinophilia, but the granules persist despite the subsequent loss of this staining characteristic. Intact granules are secreted into the lumen of the anterior canal, although their function has not been ascertained.

Animals↗

Immunocytochemical localization of an insulin-like substance in the synganglion of the tick Ornithodoros parkeri (Acari: Argasidae).

Immunocytochemical staining based on the peroxidase-antiperoxidase method has shown that some neurosecretory cells (NSC) in the synganglion of the adult female tick Ornithodoros parkeri react with an antibody to bovine insulin. There are 18 regions of paraldehyde fuchsin-positive NSC of which three regions showed specific insulin-like immunoreactivity: anterolateral cheliceral, anteromedial stomodeal and posterior opisthosomal. Immunoreactivity can also be found in the extracellular surface of the neurilemma of the synganglion. This suggests a possible neurohemal site and release of neurohormone in a diffuse manner.

Animals↗

Immunohistochemical and electron microscopic changes in the endocrine pancreas after thymectomy.

This study showed that six months after adult thymectomy blood glucose level in rats was significantly lower compared to that of control animals. The low glucose level found in thymectomized rats was accompanied by structural changes in the pancreatic islets. Electron microscopy and paraldehyde fuchsin (PAF) stained paraffin sections revealed partial degranulation of B-cells.

Animals↗

The origin of pharmacopsychology: Emil Kraepelin's experiments in Leipzig, Dorpat and Heidelberg (1882-1892).

This historical review shows that the early history of cognitive psychopharmacology, originally labelled as "pharmacopsychology", is closely linked to developments in experimental psychology and academic psychiatry. At the beginning of his scientific career, the German psychiatrist Emil Kraepelin (1856-1926) joined Wilhelm Wundt's laboratory of experimental psychology at the University of Leipzig. Although Kraepelin was fired from his clinical position at the university's psychiatric hospital, he completed his habilitation, the German equivalent of Ph.D., and started a series of pharmacological investigations in healthy volunteers using common recreational drugs (alcohol, coffee, tea) or medicinal products (amyl nitrite, chloral hydrate, chloroform, ethyl ether, morphine, paraldehyde) together with innovative psychological tasks. This paper reviews Kraepelin's pharmacopsychological research and his methodological innovations, providing translations, for the first time, from original papers, his monograph On the Modulation of Simple Psychological Processes by Some Medicines and from other sources. Kraepelin's contributions to psychopharmacology and clinical neuropsychology were far ahead of his time and his conceptual achievements have been largely neglected by modern psychiatry and cognitive neuroscience.

History, 19th Century↗

Presentation and management of eclampsia.

Three hundred forty-seven cases of eclampsia were managed at the University College Hospital (UCH), Ibadan, Nigeria from 1977 to 1986 (9.3 per 1000 deliveries). Thirty-one percent of seizures occurred antenatally, 46.2% during labor and 23.2% postnatally. Only 5% first occurred in the hospital. Seizures were controlled with diazepam, lytic cocktail (chlorpromazine, pethidine and phenergan), sodium amylobarbitone, paraldehyde and bromethol. Maternal mortality was 2.9%, and perinatal mortality 193 per 1000, respectively. Prevention of avoidable factors (absent or poor antenatal care and prolonged labor) by the provision of comprehensive antenatal care will reduce the incidence of eclampsia. Improvement in management facilities prior to transfer to referral centers, the use of magnesium sulfate or diazepam to control seizures and the avoidance of hypotonic solutions and 50% glucose during therapy will reduce morbidity and mortality.

Adolescent↗

Crystallization and X-ray data collection on human growth hormone.

Single crystals of natural sequence human growth hormone have been grown from media containing ethanol, acetone or paraldehyde. Recombinant growth hormone in its native and desamidated form and pituitary hormone have been crystallized. A full native set of diffraction data extending to 3.5 A resolution has been obtained with synchrotron radiation for crystals of recombinant human growth hormone grown from ethanol. The identity of the material in these crystals has been established by anion-exchange chromatography.

Chromatography, Ion Exchange↗

Effect of hypnotics on mice genetically selected for sensitivity to ethanol.

It was previously shown that the rate of disappearance of blood ethanol was identical for two lines of mice selectively bred for differences in sleep-time after ethanol administration. The ED50 values for the loss of righting response with ethanol were significantly different at 3.64 g per kg for the SS line and 1.65 g per kg for the LS line. In the present study the mean sleep time is 367 sec for SS mice and 9342 sec for LS mice. The ED50 values remain essentially the same as previously reported. Unchanged LD50 values for ethanol, however, are not different at 4.8 g per kg for the SS and 4.5 g per kg for the LS line of mice. The ED50 value for loss for righting response following administration of methanol, butanol and t-butanol is approximately 2 fold greater for the SS line of mice than for the LS line. The ED50 values for sodium pentobarbital or ether in the 2 lines of mice for loss of righting response are virtually identical. In addition, the sleep-time values obtained after the administration of pentobarbital, chloral hydrate, trichloroethanol and paraldehyde are not significantly different. These data indicate that while the SS and LS lines of mice differ in central nervous system sensitivity to ethanol, methanol, butanol and t-butanol it is implied that they do no differ in central nervous system sensitivity to other hypnotic agents tested. Proof of this latter suggestion awaits determination of metabolic rates, and brain levels of these other depressants.

Animals↗

Rectal administration of antiepileptic drugs in children.

This article reviews the current literature describing the use of rectally administered antiepileptic drugs. Individual antiepileptic drugs are discussed in regard to efficacy, toxicity, and rate of absorption. Absorption occurs through passive diffusion; therefore, solutions are absorbed most quickly. Paraldehyde, diazepam, secobarbital, and valproic acid are used when rapid effect for termination of prolonged or serial seizures is desired. Valproic acid, lorazepam, carbamazepine, and phenytoin all can be used for maintenance therapy.

Administration, Rectal↗

Fine structure of the Caenorhabditis elegans secretory-excretory system.

The secretory-excretory system of C. elegans, reconstructed from serial-section electron micrographs of larvae, is composed of four cells, the nuclei of which are located on the ventral side of the pharynx and adjacent intestine. (1) The pore cell encloses the terminal one-third of the excretory duct which leads to an excretory pore at the ventral midline. (2) The duct cell surrounds the excretory duct with a lamellar membrane from the origin of the duct at the excretory sinus to the pore cell boundary. (3) A large H-shaped excretory cell extends bilateral canals anteriorly and posteriorly nearly the entire length of the worm. The excretory sinus within the cell body joins the lumena of the canals with the origin of the duct. (4) A binucleate, A-shaped gland cell extends bilateral processes anteriorly from cell bodies located just behind the pharynx. These processes are fused at the anterior tip of the cell, where the cell enters the circumpharyngeal nerve ring. The processes are also joined at the anterior edge of the excretory cell body, where the excretory cell and gland are joined to the duct cell at the origin of the duct. Secretory granules may be concentrated in the gland near this secretory-excretory junction. Although the gland cells of all growing developmental stages stain positively with paraldehyde-fuchsin, the gland of the dauer larva stage (a developmentally arrested third-stage larva) does not stain, nor do glands of starved worms of other stages. Dauer larvae uniquely lack secretory granules, and the gland cytoplasm is displaced by a labyrinth of large, transparent spaces. Exit from the dauer stage results in the return of active secretory morphology in fourth-stage larvae.

Animals↗

Ultrastructure of neurosecretory cells in the pars intercerebralis of Rhodnius prolixus (Hemiptera).

Six neuron types are distinguished in the pars intercerebralis of the starved fifth instar of Rhodnius prolixus. All neuron types contain electron dense secretory granules derived from Golgi complexes which are of characteristic size and morphology in each type. The neuron types are not thought to represent stages in a secretory cycle. The variety of neuron types described is related to that revealed by staining sections of the same cells with paraldehyde fuchsin. Active synthesis of neurosecretory granules continues throughout starvation and the lysosomal system appears to be involved in the continual degradation of secretory granules. Some of the variations in granule morphology observed may be a consequence of granule fusion and the importance of cytoplasmic events in the development of neurosecretory granules is discussed.

Animals↗

Pharmacotherapy of mental illness--a historical analysis.

The history of pharmacotherapy of mental illness can be divided into three periods. Introduction of morphine, potassium bromide, chloral hydrate, hyoscine, paraldehyde, etc., during the second half of the 19th century (first period), led to the replacement of physical restraint by pharmacological means in behavior control. Introduction of nicotinic acid, penicillin, thiamine, etc., during the first half of the 20th century (second period), led to significant changes in the diagnostic distribution of psychiatric patients; psychoses due to cerebral pellagra, and dementia due to syphilitic general paralysis virtually disappeared from psychiatric hospitals, and the prevalence of dysmnesias markedly decreased. Treatment with therapeutically effective drugs of mania, schizophrenia, depression, bipolar disorder, generalized anxiety disorder, panic disorder, obsessive compulsive disorder, Alzheimer's disease, etc., during the second half of the 20th century (third period), brought to attention the heterogeneity of the populations within the diagnostic categories of schizophrenia and depression. Introduction of the first set of psychotropics and the spectrophotofluorimeter during the 1950s triggered the development of neuropsychopharmacology. Introduction of genetic technology for the separation of receptor subtypes in the 1980s opened the path for the "tailoring" of psychotropic drugs by the dawn of the 21st century, to receptor affinities.

Animals↗

Status epilepticus: management and outcome of 107 episodes.

Morbidity and mortality from status epilepticus might be reduced by attention to recommended management protocols. We studied our experience of 107 episodes of status epilepticus in 43 patients over a 5-year period. Overall mortality was 2% and permanent sequelae developed in 11 cases (10%). Although hospital admission was rapid, treatment could be initiated more quickly in the community (P < 0.0001). However treatment given before admission did not significantly reduce the duration of status (median difference 38 minutes, 95% C.I., 24 to 55 minutes). Diazepam was the first line treatment in 98 episodes, chlormethiazole and phenytoin were used in 27 and 18 episodes, respectively. Paraldehyde was used in 12 episodes. Midazolam was used in the intensive care setting in two cases. Clonazepam, lorazepam, lignocaine and phenobarbitone were not used at all. There was a marked failure to adhere to the recommended management protocols.

Adolescent↗

Hymenolepis nana: the fine structure of the 'penetration gland' and nerve cells within the oncosphere.

The fine structure of the oncosphere of Hymenolepis nana has been investigated by transmission and scanning electron microscopy, together with light microscope observations of JB-4 embedded material. The outer surface of the oncosphere is covered by an epithelial layer, termed the embryonic epithelium. Cell types present within the oncosphere include the penetration gland cell, oncoblast, or hook-forming cells, nerve cells, muscle cells (both somatic and hook), and undifferentiated 'stem' cells. The penetration gland is a large, U-shaped structure, situated in the anterior region of the oncosphere, and filled with secretory granules of 2 distinct morphological types. Histochemically, the secretory material yields reactions characteristic of an acid mucopolysaccharide. A proteinaceous-substance and small amounts of glycogen are also present. Up to 4 pairs of ducts from the penetration gland have been observed. They pass through the basal lamina and the epithelial layer to open against the polar filament layer at the anterior end of the oncosphere. Nerve cells are described in a cestode oncosphere for the first time. The cells are paraldehyde-fuchsin-positive and show a high level of secretory activity, as evidenced by the large numbers of dense-cored vesicles produced by the Golgi apparatus in the perikarya; consequently, they are tentatively regarded as possible neurosecretory cells. The vesicles are transported down the axon to be stored in specialized swollen axon terminals, which form definite junctions with the muscle cells.

Animals↗