Role of the paraventricular nucleus in controlling the frequency of milk ejection and the facilitatory effect of centrally administered oxytocin in the suckled rat

ABSTRACT The milk-ejection reflex was studied in anaesthetized, lactating Wistar rats in order to evaluate the contribution of the paraventricular nucleus (PVN) to the patterning of milk ejection and the facilitatory action of centrally administered oxytocin. In the first series of experiments, radiofrequency lesions were performed and centred: (1) antero-dorsal to the PVN, damaging parts of the medial septum and anterior hypothalamus; (2) in the PVN, such that much of the parvocellular division was destroyed, but parts of the magnocellular division remained intact; or (3) in the PVN, destroying both parvocellular and magnocellular divisions. Suckling tests performed before and after lesioning showed that the milk-ejection interval was significantly increased (decreased frequency) after lesioning in groups 2 and 3, but that milk-ejection amplitude was significantly decreased only in group 3. These results suggest that damage to the parvocellular division of the PVN affects milk-ejection frequency, but that damage to the magnocellular PVN only affects amplitude. Subsequent tests on rats injected into the PVN with the neurotoxin N-methyl-d,l-aspartate revealed a fall in the amplitude and frequency of milk ejection, similar to that after complete radiofrequency lesions of the PVN. In the second series of experiments, the facilitatory action of centrally administered oxytocin (1 mU, 2.2 ng) was examined in animals bearing either sham or complete PVN lesions. In both groups, intracerebroventricular injection of oxytocin was able to increase the frequency of milk ejections, although the incidence of milk ejection was lower in the pre- and post-injection period in the PVN-lesioned animals. In conclusion, the parvocellular component of the PVN may be an important site for regulating milk-ejection frequency, possibly mediated by its centrally projecting oxytocin neurones. However, the PVN does not appear to be the principle target site by which central oxytocin exerts its facilitatory effect on the frequency of milk ejection. Journal of Endocrinology (1990) 125, 467–475

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MESENCEPHALIC AREAS CONTROLLING PULSATILE OXYTOCIN RELEASE IN THE SUCKLED RAT

Journal of Endocrinology ◽

10.1677/joe.0.0910233 ◽

1981 ◽

Vol 91 (2) ◽

pp. 233-244 ◽

Cited By ~ 42

Author(s):

T. S. JUSS ◽

J. B. WAKERLEY

Keyword(s):

Medial Geniculate Body ◽

Milk Ejection ◽

Ventral Tegmentum ◽

Irregular Pattern ◽

Oxytocin Release ◽

Medial Geniculate ◽

Radiofrequency Lesions ◽

Milk Ejection Reflex ◽

Bilateral Lesions ◽

And Control

Experiments were performed on anaesthetized lactating rats to investigate the effects of radiofrequency lesions of the mesencephalon on the milk-ejection reflex. In lesioned and control rats, intramammary pressure recordings were used to estimate oxytocin release (number and relative amplitude of the intermittent milk-ejection responses) during a 3-h suckling test with ten pups. Bilateral lesions (diameter 0·5–1·5 mm) of the lateral tegmentum (near the brachium of the inferior colliculus and medial geniculate body) seriously disrupted the milk-ejection reflex, reducing the number of rats ejecting milk (two out of ten v. all 12 controls, P<0·001) and the amount of oxytocin they released (1·35±0·35 (s.e.m.) v. 15·52±2·19 mu. for controls, P<0·05). Unilateral lesions of the lateral tegmentum also impaired milk ejection and, if the suckling stimulus was restricted only to the contralateral nipples, oxytocin release was virtually abolished. Bilateral lesions placed more medially in the intermediate tegmentum were far less disruptive (eight out of nine rats ejected milk), though the amount of oxytocin released in this group (8·64±1·88 mu.) was still significantly (P<0·05) lower than controls. All rats with lesions of the central grey (nine) or ventral tegmentum (eight) displayed reflex milk ejection, as did those with multiple lesions of the tectum, central grey and ventral tegmentum (seven); in these three groups the amounts of oxytocin released (13·88±2·68, 13·10±1·90 and 11·04±1·95 mu. respectively) did not differ significantly from controls. Damage to the ventral tegmentum produced an irregular pattern of milk ejection characterized by occasional abnormally short (<2 min) milk-ejection intervals, though the overall number of responses in 3 h was less than that of controls (20·83±1·82 v. 14·50±1·30 mu., P<0·05). In conclusion, these results delineate two mesencephalic areas of particular importance in the milk-ejection reflex: (a) the lateral tegmentum, which appears to be concerned with transmission of the suckling stimulus from the contralateral nipples and is indispensable for oxytocin release, and (b) the ventral tegmentum which, although not an essential component of the reflex, may contribute to the timing of the intermittent milk-ejection responses.

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The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis

Nutrients ◽

10.3390/nu13041337 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1337

Author(s):

Joseph Yusin ◽

Vivian Wang ◽

Susanne M. Henning ◽

Jieping Yang ◽

Chi-Hong Tseng ◽

...

Keyword(s):

Allergic Rhinitis ◽

Nasal Spray ◽

Placebo Tablet ◽

Group 4 ◽

Cytokine Levels ◽

Before And After ◽

Group 3 ◽

Nasal Steroid ◽

Group 2 ◽

Broccoli Sprout

Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures.

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Neuroendocrine Control of the Milk Ejection Reflex

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(83)82072-4 ◽

1983 ◽

Vol 66 (10) ◽

pp. 2226-2235 ◽

Cited By ~ 17

Author(s):

Gordon T. Goodman ◽

Clark E. Grosvenor

Keyword(s):

Milk Ejection ◽

Neuroendocrine Control ◽

Milk Ejection Reflex

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Lesion and electrophysiological studies on the hypothalamic afferent pathway of the milk ejection reflex in the rat

Neuroscience ◽

10.1016/0306-4522(92)90211-j ◽

1992 ◽

Vol 50 (4) ◽

pp. 877-883 ◽

Cited By ~ 30

Author(s):

S. Takano ◽

H. Negoro ◽

K. Honda ◽

T. Higuchi

Keyword(s):

Afferent Pathway ◽

Milk Ejection ◽

Electrophysiological Studies ◽

Milk Ejection Reflex

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Eco-Friendly Dye-free Coloration Technology for Wool Based on Fenton Reagent Pretreatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.3327 ◽

2011 ◽

Vol 239-242 ◽

pp. 3327-3330 ◽

Cited By ~ 2

Author(s):

Yan Ling Sui ◽

Yong Zhu Cui

Keyword(s):

Nitric Acid ◽

Emission Reduction ◽

Optimal Conditions ◽

Fenton Reagent ◽

Saving Energy ◽

Before And After ◽

Series Of Experiments

The wool was pretreated with Fenton reagent in this paper, on this basis, 4-hydroxy benzaldehyde and concentrated nitric acid were used to discuss the dye-free coloration deeply. It was analyzed comparatively through a series of experiments on the wool before and after Fenton reagent pretreatment, and the effects of concentrations, temperature and time on the coloration were further discussed. The experiment indicated that, compared with untreated wool, the color of wool with Fenton reagent pretreatment was deeper and the coloration rate was quicker. It realized good coloration at lower temperatures, which achieved the goal of saving energy and emission reduction. The optimal conditions were that concentrations of 4-hydroxy benzaldehyde and concentrated nitric acid were 2.5% and 3% respectively, reacting time was 90min, and reacting temperature was 70°C.

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Sleep is not a prerequisite for the milk ejection reflex in the pig

Experimental Brain Research ◽

10.1007/bf00238817 ◽

1981 ◽

Vol 43 (1) ◽

Cited By ~ 18

Author(s):

D.A. Poulain ◽

F. Rodriguez ◽

F. Ellendorff

Keyword(s):

Milk Ejection ◽

Milk Ejection Reflex

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μ-Opioid modulation in the rostral solitary nucleus and reticular formation alters taste reactivity: evidence for a suppressive effect on consummatory behavior

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00142.2011 ◽

2011 ◽

Vol 301 (3) ◽

pp. R690-R700 ◽

Cited By ~ 9

Author(s):

Nicole R. Kinzeler ◽

Susan P. Travers

Keyword(s):

Reticular Formation ◽

Neural Control ◽

Suppressive Effect ◽

Neutral Stimulus ◽

Endogenous Opioids ◽

Facilitatory Effect ◽

Consummatory Behavior ◽

Taste Reactivity ◽

Before And After ◽

Ventral Border

The neural control of feeding involves many neuromodulators, including the endogenous opioids that bind μ-opioid receptors (MORs). Injections of the MOR agonist, Damgo, into limbic and hypothalamic forebrain sites increase intake, particularly of palatable foods. Indeed, forebrain Damgo injections increase sucrose-elicited licking but reduce aversive responding (gaping) to quinine, suggesting that MOR activation may enhance taste palatability. A μ-opioid influence on taste reactivity has not been assessed in the brain stem. However, MORs are present in the first-order taste relay, the rostral nucleus of the solitary tract (rNST), and in the immediately subjacent reticular formation (RF), a region known to be essential for consummatory responses. Thus, to evaluate the consequences of rNST/dorsal RF Damgo in this region, we implanted rats with intraoral cannulas, electromyographic electrodes, and brain cannulas aimed at the ventral border of the rNST. Licking and gaping elicited with sucrose, water, and quinine were assessed before and after intramedullary Damgo and saline infusions. Damgo slowed the rate, increased the amplitude, and decreased the size of fluid-induced lick and gape bouts. In addition, the neutral stimulus water, which typically elicits licks, began to evoke gapes. Thus, the current results demonstrate that μ-opioid activation in the rNST/dorsal RF exerts complex effects on oromotor responding that contrast with forebrain effects and are more indicative of a suppressive, rather than a facilitatory effect on ingestion.

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Cavitation Erosion of HVOF Coatings

Thermal Spray 1996: Proceedings from the National Thermal Spray Conference ◽

10.31399/asm.cp.itsc1996p0153 ◽

1996 ◽

Author(s):

R. Schwetzke ◽

H. Kreye

Keyword(s):

Erosion Rate ◽

Cavitation Erosion ◽

Metallic Alloys ◽

Erosion Mechanism ◽

Hvof Coatings ◽

Coating Composition ◽

Before And After ◽

Series Of Experiments ◽

The Individual ◽

Scanning Electron

Abstract The proposed paper reports a series of experiments to investigate the cavitation erosion mechanism of HVOF coatings. Vibratory cavitation erosion tests according to ASTM G 32 have been carried out with several HVOF coatings including cermets, oxides and metallic alloys. The steady state erosion rate for each coating was determined and the effect of coating composition and microstructure on the erosion rate was investigated. The morphology and microstructure of the various coatings before and after cavitation testing were analyzed by means of light optical and scanning electron microscopy in order to study the erosion mechanism. The results demonstrate that HVOF coatings of NiCrFeBSi, WC-17Co, Cr3C2-25NiCr and Cr2O3 can exhibit a rather high resistance against cavitation erosion and should be considered for application as a protective surface layer against cavitation. Furthermore, it is shown that cavitation testing can provide a useful tool to study and characterize the bond strength between individual splats as well as the brittleness of the individual phases present in the coating.

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