Neonatal maternal separation in male rats increases intestinal permeability and affects behavior after chronic social stress

2012 ◽  
Vol 105 (4) ◽  
pp. 1058-1066 ◽  
Author(s):  
E. Øines ◽  
R. Murison ◽  
J. Mrdalj ◽  
J. Grønli ◽  
A.M. Milde
Keyword(s):  
Intestinal Permeability ◽  
Social Stress ◽  
Maternal Separation ◽  
Male Rats ◽  
Chronic Social Stress ◽  
Neonatal Maternal Separation

Regulation of catecholamine-synthesizing enzymes in adrenals of Wistar rats under chronic stress

1993 ◽  
Vol 264 (5) ◽  
pp. R957-R962 ◽  
Author(s):  
V. Lemaire ◽  
M. Le Moal ◽  
P. Mormede
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Social Stress ◽  
Specific Activity ◽  
Sympathetic Innervation ◽  
Male Rats ◽  
Adrenal Weight ◽  
Inhibitory Influence ◽  
Chronic Social Stress ◽  
Sympathetic Nervous

We have shown previously that chronic social stress has differential effects on adrenal weight and on tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) specific activity, depending on the experimental design. To determine the role of the sympathetic nervous system and of the hypothalamo-pituitary-adrenocortical axis (HPAA) in these modifications, we studied the mechanisms of regulation of these parameters in basal conditions as well as in response to reserpine treatment and chronic social stress in the Wistar strain of rats. We found that the adrenal weight is mostly dependent on the activity of the HPAA, which is increased in male rats living in mixed-sex colonies. PNMT specific activity is regulated by splanchnic innervation, confirming that its induction by social instability is a consequence of sympathetic nervous system hyperactivity. The increase of TH specific activity, as seen in unstable, mixed-sex colonies, is not under sympathetic control. However, we show that the pituitary may exert a tonic inhibitory influence, dependent on the sympathetic innervation. These data confirm that the HPAA and the sympathetic nervous system may be independently triggered in chronic social stress conditions.

Neonatal maternal separation enhances phrenic responses to hypoxia and carotid sinus nerve stimulation in the adult anesthetized rat

2005 ◽  
Vol 99 (1) ◽  
pp. 189-196 ◽  
Author(s):  
Richard Kinkead ◽  
Roumiana Gulemetova ◽  
Aida Bairam
Keyword(s):  
Nerve Stimulation ◽  
Maternal Separation ◽  
Carotid Sinus ◽  
Ventilatory Response ◽  
Male Rats ◽  
Hypoxic Ventilatory Response ◽  
Carotid Sinus Nerve ◽  
Neonatal Maternal Separation ◽  
Carotid Sinus Nerve Stimulation ◽  
Series Of Experiments

In awake animals, our laboratory recently showed that the hypoxic ventilatory response of adult male (but not female) rats previously subjected to neonatal maternal separation (NMS) is 25% greater than controls (Genest SE, Gulemetova R, Laforest S, Drolet G, and Kinkead R. J Physiol 554: 543–557, 2004). To begin mechanistic investigations of the effects of this neonatal stress on respiratory control development, we tested the hypothesis that, in male rats, NMS enhances central integration of carotid body chemoafferent signals. Experiments were performed on two groups of adult male rats. Pups subjected to NMS were placed in a temperature-controlled incubator 3 h/day from postnatal day 3 to postnatal day 12. Control pups were undisturbed. At adulthood (8–10 wk), rats were anesthetized (urethane; 1.6 g/kg), paralyzed, and ventilated with a hyperoxic gas mixture [inspired O2 fraction (FiO2) = 0.5], and phrenic nerve activity was recorded. The first series of experiments aimed to demonstrate that NMS-related enhancement of the inspiratory motor output (phrenic) response to hypoxia occurs in anesthetized animals also. In this series, rats were exposed to moderate, followed by severe, isocapnic hypoxia (FiO2 = 0.12 and 0.08, respectively, 5 min each). NMS enhanced both the frequency and amplitude components of the phrenic response to hypoxia relative to controls, thereby validating the use of this approach. In a second series of experiments, NMS increased the amplitude (but not the frequency) response to unilateral carotid sinus nerve stimulation (stimulation frequency range: 0.5–33 Hz). We conclude that enhancement of central integration of carotid body afferent signal contributes to the larger hypoxic ventilatory response observed in NMS rats.

scholarly journals Meal patterns and hypothalamic NPY expression during chronic social stress and recovery

2010 ◽  
Vol 299 (3) ◽  
pp. R813-R822 ◽  
Author(s):  
Susan J. Melhorn ◽  
Eric G. Krause ◽  
Karen A. Scott ◽  
Marie R. Mooney ◽  
Jeffrey D. Johnson ◽  
...  
Keyword(s):  
Food Intake ◽  
Social Stress ◽  
Recovery Period ◽  
Ingestive Behavior ◽  
Meal Size ◽  
Male Rats ◽  
Dominant Male ◽  
Mrna Levels ◽  
Meal Patterns ◽  
Chronic Social Stress

In the present study, we examined meal patterns during and after exposure to the visible burrow system (VBS), a rodent model of chronic social stress, to determine how the microstructure of food intake relates to the metabolic consequences of social subordination. Male Long-Evans rats were housed in mixed-sex VBS colonies (4 male, 2 female) for 2 wk, during which time a dominance hierarchy formed [1 dominant male (DOM) and 3 subordinate males (SUB)], and then male rats were individually housed for a 3-wk recovery period. Controls were individually housed with females during the 2-wk VBS period and had no changes in ingestive behavior compared with a habituation period. During the hierarchy-formation phase of VBS housing, DOM and SUB had a reduced meal frequency, whereas SUB also had a reduced meal size. However, during the hierarchy-maintenance phase of VBS housing, DOM meal patterns did not differ from controls, whereas SUB continued to display a reduced food intake via less frequent meals. During recovery, DOM had comparable meal patterns to controls, whereas SUB had an increased meal size. Hypothalamic neuropeptide Y (NPY) mRNA levels were not different between these groups during the experimental period. Together, the results suggest that exposure to chronic social stress alters ingestive behavior both acutely and in the long term, which may influence the metabolic changes that accompany bouts of stress and recovery; however, these differences in meal patterns do not appear to be mediated by hypothalamic NPY.

Neonatal stress and attenuation of the hypercapnic ventilatory response in adult male rats: the role of carotid chemoreceptors and baroreceptors

2010 ◽  
Vol 299 (5) ◽  
pp. R1279-R1289 ◽  
Author(s):  
Frédéric S. Dumont ◽  
Richard Kinkead
Keyword(s):  
Adult Male ◽  
Maternal Separation ◽  
Ventilatory Response ◽  
Respiratory Control ◽  
Pressure Change ◽  
Male Rats ◽  
Arterial Blood ◽  
Carotid Bodies ◽  
Neonatal Maternal Separation ◽  
Underlying Mechanisms

Neonatal maternal separation (NMS) is a form of stress that disrupts respiratory control development. Awake adult male rats previously subjected to NMS show a ventilatory response to hypercapnia (HCVR; FiCO2 = 0.05) 47% lower than controls; however, the underlying mechanisms are unknown. To address this issue, we first tested the hypothesis that carotid bodies contribute to NMS-related attenuation of the HCVR by using carotid sinus nerve section or FiO2 manipulation to maintain PaO2 constant (iso-oxic) during hypercapnic hyperpnea. We then determined whether NMS-related augmentation of baroreflex sensitivity contributes to the reduced HCVR in NMS rats. Nitroprusside and phenylephrine injections were used to manipulate arterial blood pressure in both groups of rats. Pups subjected to NMS were separated from their mother 3 h/day from postnatal days 3 to 12. Control rats were undisturbed. At adulthood, rats were anesthetized [urethane (1g/kg) + isoflurane (0.5%)], and diaphragmatic electromyogram (dEMG) was measured under baseline and hypercapnic conditions (PaCO2: 10 Torr above baseline). The relative minute activity response to hypercapnia of anesthetized NMS rats was 34% lower than controls. Maintaining PaO2 constant during hypercapnia reversed this phenotype; the HCVR of NMS rats was 45% greater than controls. Although the decrease in breathing frequency during baroreflex activation was greater in NMS rats, the change observed within the range of pressure change observed during hypercapnia was minimal. We conclude that NMS-related changes in carotid body sensitivity to chemical stimuli and/or its central integration is a key mechanism in the attenuation of HCVR by NMS.

Repeated neonatal maternal separation alters morphine-induced antinociception in male rats

2001 ◽  
Vol 54 (6) ◽  
pp. 649-654 ◽  
Author(s):  
Mikhail Kalinichev ◽  
Keith W Easterling ◽  
Stephen G Holtzman
Keyword(s):  
Maternal Separation ◽  
Male Rats ◽  
Neonatal Maternal Separation

Impact of Experimental Chronic Social Stress on Biliary Bile Acid Content in Male Rats

2018 ◽  
Vol 9 (2) ◽  
pp. 127-133
Author(s):  
A.M. Liashevych ◽  
I.I. Tubalceva ◽  
Yevdokiya M. Reshetnik ◽  
Oleksandr V. Bondarenko ◽  
Stanislav P. Veselsky ◽  
...  
Keyword(s):  
Bile Acid ◽  
Acid Content ◽  
Social Stress ◽  
Male Rats ◽  
Chronic Social Stress ◽  
Biliary Bile Acid

Dietary choline during periadolescence attenuates cognitive damage caused by neonatal maternal separation in male rats

2015 ◽  
Vol 20 (6) ◽  
pp. 327-335 ◽  
Author(s):  
Hayarelis Moreno Gudiño ◽  
Diamela Carías Picón ◽  
Isabel de Brugada Sauras
Keyword(s):  
Maternal Separation ◽  
Male Rats ◽  
Neonatal Maternal Separation ◽  
Dietary Choline

Neonatal maternal separation induces sex-specific augmentation of the hypercapnic ventilatory response in awake rat

2007 ◽  
Vol 102 (4) ◽  
pp. 1416-1421 ◽  
Author(s):  
Sophie-Emmanuelle Genest ◽  
Roumiana Gulemetova ◽  
Sylvie Laforest ◽  
Guy Drolet ◽  
Richard Kinkead
Keyword(s):  
Tidal Volume ◽  
Maternal Separation ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Male Rats ◽  
Lower Tidal Volume ◽  
Hypercapnic Ventilatory Response ◽  
Specific Effects ◽  
Awake Rat ◽  
Neonatal Maternal Separation

Neonatal maternal separation (NMS) is a form of stress that exerts persistent, sex-specific effects on the hypoxic ventilatory response. Adult male rats previously subjected to NMS show a 25% increase in the response, whereas NMS females show a response 30% lower than controls ( 8 ). To assess the extent to which NMS affects ventilatory control development, we tested the hypothesis that NMS alters the ventilatory response to hypercapnia in awake, unrestrained rats. Pups subjected to NMS were placed in a temperature- and humidity-controlled incubator 3 h/day for 10 consecutive days (P3 to P12). Control pups were undisturbed. At adulthood (8 to 10 wk old), rats were placed in a plethysmography chamber for measurement of ventilatory parameters under baseline and hypercapnic conditions (inspired CO2 fraction = 0.05). After 20 min of hypercapnia, the minute ventilation response measured in NMS males was 47% less than controls, owing to a lower tidal volume response (22%). Conversely, females previously subjected to NMS showed minute ventilation and tidal volume responses 63 and 18% larger than controls respectively. Although a lower baseline minute ventilation contributes to this effect, the higher minute ventilation/CO2 production response observed in NMS females suggests a greater responsiveness to CO2/H+ in this group. We conclude that NMS exerts sex-specific effects on the hypercapnic ventilatory response and that the neural mechanisms affected by NMS likely differ from those involved in the hypoxic chemoreflex.

scholarly journals The Influence of Corvitin on the Cholates Content in the Male Rats’ Liver under the Conditions of Chronic Social Stress

2021 ◽  
Vol 6 (4) ◽  
pp. 186-192
Author(s):  
A. M. Liashevych ◽  
◽  
І. S. Lupaina ◽  
M. Yu. Makarchuk ◽  
◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Social Stress ◽  
Experimental Studies ◽  
Male Rats ◽  
Blood Cholesterol ◽  
Cognitive Test ◽  
Secretory Function ◽  
Research Activity ◽  
Chronic Social Stress

The creation of universally effective and safe correctors of biliary secretion disorders is becoming more timely. There is an urgent need for scientists to find drugs that would correct blood cholesterol levels and metabolism in liver effectively and without limiting side effects. The purpose of the study was to investigate the possibility of using corvitin to correct stress-induced biliary disorders of the liver of male rats. Materials and methods. The article looks at recent research dealing with changes in the bile acid composition of outbred male rats’ bile under chronic social stress (social defeat in daily male confrontations, 14 days) when using Corvitin (1 mg/kg, intragastrically, 7 days). Chronic social stress was created by daily agonistic interactions between animals. The state of memory and the level of research activity in the object recognition test (cognitive test) were also studied. The main fractions of conjugated bile acids (taurocholic, taurohenodeoxycholic and taurodeoxycholic, glycocholic, glycochenodeoxycholic and glycodeoxycholic and free ones – cholic, chenodeoxycholic and deoxycholic) were determined by the method of thin layer chromatography of bile. Results and discussion. Chronic social stress leads to a slight increase in the overall activity of the experimental animals, but significantly impairs the processes of recognition and memory. Social stress significantly inhibits the processes that ensure the synthesis, biotransformation and transport of bile acids in the bile. Also, chronic social stress causes changes in bile production, which reduce the solubilization properties of bile and increase the risk of lithogenesis. Conclusion. The use of Corvitin simultaneously with the simulation of experimental social stress normalized the biliary secretory function of the liver, which indicates a high potential for the use of Corvitin as a corrective factor in chronic social stress. Corvitin used by us in the conditions of experimental social stress to some extent corrected the content of bile acids in the liver of male rats, which indicates the ability of this drug to interfere with the metabolism of cholate in liver cells, in the mechanisms of bile acid transport. Correction of stress-induced pathologies of liver bile-secretory function by Corvitin requires further thorough experimental studies

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