Light-Evoked Neural Activity in the Intermediate Lobe of the Pituitary of Rana pipiens: Electrophysiological Evidence for a Neural Pathway Linking the Eyes With the Pars Intermedia

1974 ◽  
Vol 15 (5) ◽  
pp. 267-280 ◽  
Author(s):  
D.C. Dawson ◽  
C.L. Ralph
Keyword(s):  
Neural Activity ◽  
Rana Pipiens ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Neural Pathway ◽  
Electrophysiological Evidence

Serotonin sets the day state in the neurons that control coupling between the optic lobe circadian pacemakers in the cricketGryllus bimaculatus

2002 ◽  
Vol 205 (9) ◽  
pp. 1305-1314 ◽  
Author(s):  
A. S. M. Saifullah ◽  
Kenji Tomioka
Keyword(s):  
Neural Activity ◽  
Receptor Agonist ◽  
Serotonin Receptor ◽  
Optic Lobe ◽  
Neural Pathway ◽  
Gryllus Bimaculatus ◽  
Dependent Inhibition ◽  
Serotonin Receptor Antagonist ◽  
Time Dependent Inhibition ◽  
Circadian Pacemakers

SUMMARYThe bilaterally paired optic lobe circadian pacemakers of the cricket Gryllus bimaculatus mutually exchange photic and circadian information to keep their activity synchronized. The information is mediated by a neural pathway, consisting of the so-called medulla bilateral neurons,connecting the medulla areas of the two optic lobes. We investigated the effects of serotonin on the neural activity in this coupling pathway. Spontaneous and light-induced electrical activity of the neurons in the coupling pathway showed daily variations, being more intense during the night than the day. Microinjection of serotonin or a serotonin-receptor agonist,quipazine, into the optic lobe caused a dose- and time-dependent inhibition of spontaneous and light-induced responses, mimicking the day state. The amount of suppression was greater and the recovery from the suppression occurred faster during the night. Application of metergoline, a non-selective serotonin-receptor antagonist, increased spontaneous activity and light-evoked responses during both the day and the night, with higher effect during the day. In addition, metergoline effectively attenuated the effects of serotonin. These facts suggest that in the cricket's optic lobe, serotonin is released during the daytime and sets the day state in the neurons regulating coupling between the bilaterally paired optic lobe circadian pacemakers.

Neurosecretory innervation of the pituitary of the eels Anguilla and Conger I. The structure and ultrastructure of the neuro-intermediate lobe under normal and experimental conditions

1966 ◽  
Vol 250 (768) ◽  
pp. 311-327 ◽  
Keyword(s):  
Sea Water ◽  
Synaptic Contact ◽  
Type A ◽  
White Background ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Experimental Conditions ◽  
Synaptic Junctions ◽  
Neurosecretory Fibre ◽  
Structure And Ultrastructure

Three kinds of neurosecretory fibre (Types A 1 , A 2 and B) are present in the neural component of the neuro-intermediate lobe of the eel pituitary. These fibres do not in the main make any direct contact with the pars intermedia cells, but they are separated by only a narrow extravascular channel, into which both elements discharge their products. Type A neurosecretory fibres do, however, make direct synaptic contact with pituicytes which resemble ependyma and surround finger-like extensions of the infundibular recess. That these contacts are functional is indicated by the fact that their frequency is related to changes in the environment. When eels are placed on an illuminated white background the synaptic junctions between Type A 2 neurosecretory fibres and pituicytes are very frequent. Similar synaptic junctions between A 1 fibres and pituicytes were only found in animals which had been recently transferred from fresh water to sea water. A possibility that the pituicytes play some part in a feed-back from the pituitary to the hypothalamus is discussed.

Interleukin-1β stimulates cell proliferation in the intermediate lobe of the rat pituitary gland

1994 ◽  
Vol 140 (3) ◽  
pp. 337-341 ◽  
Author(s):  
H Stępień ◽  
G Żerek-Mełen ◽  
S Mucha ◽  
K Winczyk ◽  
J Fryczak
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Pituitary Gland ◽  
Molecular Forms ◽  
Brdu Incorporation ◽  
Immunocytochemical Staining ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Intermediate Cell ◽  
Receptor Antibody

Abstract Interleukin-1 (IL-1) is a multifunctional monokine which possesses an impressive array of diverse actions relating to the function of the immune system. IL-1 is present and formed locally in the brain as demonstrated by biochemical and immunocytochemical methods. Various immunomodulatory and neuroendocrine effects of IL-1 have been reported, including induction of several morphological changes in the endocrine cells of experimental animals and humans. IL-1 is present in two molecular forms (IL-1α and IL-1β) that activate specific receptors for IL-1. In the present study we investigated the possible effect of recombinant human IL-1α and IL-1β and recently cloned anti-human IL-1 receptor antibody (M10) on cell proliferation in the anterior and the intermediate lobe of the pituitary gland of the rat. In vivo labelling with bromodeoxyuridine (BrdU) and immunocytochemical staining with anti-BrdU monoclonal antibody were used as a sensitive index of cell proliferation. IL-1β was found to stimulate dose-dependently (0·1–10 μg/kg body weight) incorporation of BrdU into pituitary intermediate cell nuclei, and positive correlation between the tested doses of IL-1β and BrdU-labelling index was noted (r=0·89; P<0·01). This IL-1β-induced stimulation of pituitary pars intermedia cell proliferation was receptor specific, since stimulation was blocked by anti-IL-1 receptor antibody. On the other hand, recombinant human IL-1α did not affect BrdU incorporation and the proliferation of pituitary pars intermedia cells. In addition, neither of the cytokines tested in the same experimental conditions showed any effect on the cell growth of the pituitary pars anterior. These results suggest that IL-1β may be involved in the regulation of the cell growth of the pituitary intermediate lobe in rats. Journal of Endocrinology (1994) 140, 337–341

scholarly journals Testing the Efforts Model of Simultaneous Interpreting: An ERP Study

2017 ◽  
Author(s):  
Roman Koshkin ◽  
Yury Shtyrov ◽  
Alex Ossadtchi
Keyword(s):  
Working Memory ◽  
Neural Activity ◽  
Event Related Potential ◽  
Auditory Stimuli ◽  
Simultaneous Interpretation ◽  
Simultaneous Interpreting ◽  
Electrophysiological Evidence ◽  
Task Irrelevant ◽  
Different Levels

AbstractWe utilized the event-related potential (ERP) technique to study neural activity associated with different levels of working memory (WM) load during simultaneous interpretation (SI) in an ecologically valid setting. The amplitude of N1 and P1 components elicited by task-irrelevant tone probes was significantly modulated as a function of WM load but not the direction of interpretation. Furthermore, the latency of the N1 increased insignificantly with WM load. The P1 latency, however, mostly did not depend on either WM load or direction of interpretation. Larger negativity under lower WM loads suggests deeper processing of the auditory stimuli, providing tentative electrophysiological evidence in support of the Efforts Model of SI. Relationships between the direction of interpretation and median WM load are also discussed.

Memoirs: A Study of the Histology of the Pituitary Gland of the Skate

1936 ◽  
Vol s2-78 (312) ◽  
pp. 637-651
Author(s):  
N. H. HOWES
Keyword(s):  
Pituitary Gland ◽  
Ventral Surface ◽  
Anterior Region ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Pars Tuberalis ◽  
Ventral Lobe ◽  
Pars Anterior

1. The structure of the pituitary of the adult skate is described. 2. This gland shows two distinct regions of growth which can be correlated with increase of size of the animal. 3. The pars anterior can be subdivided into three regions differing by the staining reactions of their constituent cells: (a) an anterior region where deep-purple chromaphil cells are found; (b) a middle, where they are faintly basiphil; and (c) a posterior, where they are mainly acidophil. 4. It is suggested that these regions are homologous with the pars tuberalis, basiphil, and oxyphil areas respectively of the pars anterior of the mammalian pituitary. 5. The oxyphil cells show an iodine-leucobase reaction similar to that given by the oxyphil cells of the ox pituitary. 6. The ventral lobe is a completely separate structure from the pars intermedia, although it may run along the ventral surface of the latter for some distance. 7. The histology of the neuro-intermediate lobe is described.

Beta-adrenergic stimulation of the release of ACTH- and LPH-related peptides from the pars intermedia of the rat pituitary gland

1981 ◽  
Vol 97 (3) ◽  
pp. 343-351 ◽  
Author(s):  
F.J. H. Tilders ◽  
M. Post ◽  
S. Jackson ◽  
P.J. Lowry ◽  
P. G. Smelik
Keyword(s):  
Pituitary Gland ◽  
Cortical Cell ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Spontaneous Release ◽  
Adrenergic Stimulation ◽  
Similar Time ◽  
In Vitro Superfusion ◽  
Rat Pituitary

Abstract. The intermediate lobe of the rat pituitary gland produces a series of peptides related to ACTH and LPH. The spontaneous and isoproterenol-stimulated release of such peptides was studied during in vitro superfusion of rat neurointermediate lobes with Krebs-Ringer medium. Products released into the superfusion medium were quantified by direct measurement or after chromatography on Sephadex G-50. ACTH bioactivity was determined by use of adrenal cortical cell suspension assay. In addition, NH2-terminal ACTH, CO2H-terminal ACTH, α-MSH and β-endorphin radioimmunoassays were used. The results show that 1. neurointermediate lobes of rats secrete spontaneously various ACTH- and LPH-related peptides in amounts proportional to the amounts in which these peptides are found in extracts of the neurointermediate lobe; 2. the β-adrenergic agonist, isoproterenol, stimulated the spontaneous release of various peptides, including α-MSH, ACTH, CLIP, glycosylated CLIP, and β-endorphin-like peptides; 3. isoproterenol induced a dose-dependent (10−9–10−7 m), parallel increase in the release of α-MSH and ACTH following similar time courses and showing indentical EC50 values (about 10−8 m). Although the spontaneous release of α-MSH and ACTH from rat neurointermediate lobes is not strictly coupled under the conditions used in this study, isoproterenol seems to affect the spontaneous release of these peptides to the same relative extent.

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