Increased thirst and hunger in adult rats undernourished as infants: an alternative explanation

1. Rats were undernourished in early life by feeding their mothers a restricted quantity of a good-quality diet throughout lactation. Their undernutrition continued postweaning from 25 to 42 d of age, after which they were fed ad lib. Control rats were well nourished at all times.2. Behavioural assessment of thirst was carried out on adult males. These were deprived of water for 23 h/d throughout the period of testing. Compared to control rats, previously-undernourished (PU) rats pressed a lever at a higher rate in a Skinner box to gain a water reward, drank more frequently during their first 5 min in an unfamiliar cage, and tended to run more quickly down an alleyway for water. PU rats also drank more (/kg body-weighta0.75) of a quinine solution (1 g/l) when this was available to them ad lib. as their only source of fluid.3. A second group of rats was growth-retarded during gestation and the suckling and early postweaning periods. The rats had free access to food from 42 d of age. In adulthood their ad lib. food and water consumption was measured. PU males ate and drank more (/kg body-weight0.75) than control males.4. These results indicate that adult rats which have been undernourished in early life display increased thirst. An attempt is made to explain this finding, together with their previously-demonstrated enhanced hunger drive, purely in terms of gross anatomical and physiological differences.

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Thresholds of response to electric shock in previously undernourished rats

British Journal Of Nutrition ◽

10.1017/s0007114575000554 ◽

1975 ◽

Vol 34 (3) ◽

pp. 511-516 ◽

Cited By ~ 54

Author(s):

J. L. Smart ◽

T. S. Whatson ◽

J. Dqbbing

Keyword(s):

Electric Shock ◽

Early Life ◽

Shock Level ◽

The Other ◽

Male Rats ◽

Adult Males ◽

Pregnancy And Lactation ◽

Quality Diet ◽

Behavioural Tests

1. Rats were undernourished in early life by feeding their mothers a restricted quantity of a good-quality diet during pregnancy and lactation. All offspring were fed ad lib. from weaning. Behavioural tests were done using adult males.2. Thresholds of aversion to electric shock were determined in a rectangular box, one side of which was designated ‘live’ and the other ‘safe’ (o V side) for any particular shock level. Three 15 min sessions were given at each of five shock levels. Previously undernourished rats had a lower aversion threshold than controls. They spent more time than controls on the o V side at two intermediate levels of shock.3. Other male rats were subjected to six graded series of brief, unavoidable shocks. Previously undernourished rats responded to a greater total number of shocks than controls.4. These results support the hypothesis that previously undernourished rats have a lowered threshold of arousal.

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The effects of early life stress on context fear generalization in adult rats.

Behavioral Neuroscience ◽

10.1037/bne0000289 ◽

2019 ◽

Vol 133 (1) ◽

pp. 50-58 ◽

Cited By ~ 4

Author(s):

Nathalie D. Elliott ◽

Rick Richardson

Keyword(s):

Life Stress ◽

Early Life ◽

Early Life Stress ◽

Adult Rats ◽

Fear Generalization

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Early life maternal deprivation attenuates morphine induced inhibition in lateral paragigantocellularis neurons in adult rats

Brain Research Bulletin ◽

10.1016/j.brainresbull.2021.01.011 ◽

2021 ◽

Vol 169 ◽

pp. 128-135

Author(s):

Hossein Masrouri ◽

Maryam Azadi ◽

Saeed Semnanian ◽

Hossein Azizi

Keyword(s):

Early Life ◽

Maternal Deprivation ◽

Adult Rats

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Effect of Severe Undernutrition in Early Life on Growth, Brain Size and Composition in Adult Rats

Journal of Nutrition ◽

10.1093/jn/94.4.419 ◽

1968 ◽

Vol 94 (4) ◽

pp. 419-426 ◽

Cited By ~ 58

Author(s):

Helen A. Guthrie ◽

Myrtle L. Brown

Keyword(s):

Early Life ◽

Brain Size ◽

Adult Rats

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Abstract 403: Renal Denervation Reveals Renal Sympathetic Activation in Adult Rats Exposed to Early Life Stress

Hypertension ◽

10.1161/hyp.60.suppl_1.a403 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Analia S Loria ◽

Michael W Brands ◽

David M Pollock ◽

Jennifer S Pollock

Keyword(s):

Life Stress ◽

Early Life ◽

Renal Denervation ◽

Early Life Stress ◽

Male Rats ◽

Renal Nerves ◽

Adult Rats ◽

Baseline Conditions ◽

Control Sham ◽

Renal Sympathetic

We previously reported that maternal separation (MS), a model of early life stress, does not modify baseline blood pressure in adult rats, but increases sensitivity to hypertensive stimuli. Under baseline conditions, adult male rats exposed to MS have significantly reduced glomerular filtration rate (GFR). Acute phenylephrine-induced reductions in renal blood flow is significantly attenuated in rats exposed to MS compared to control rats. Furthermore, norephinephrine (NE) content was increased in renal cortex of MS rats compared to control rats (p<0.05). These data indicate that MS induces increased renal sympathetic outflow. Thus, we hypothesized that renal denervation will normalize GFR in rats exposed to MS. Male WKY rat pups were separated from their mothers for 3 hrs/day during the morning hours from day 2 to 14 of life. Male non-separated littermates served as control rats. Experiments were performed in 300-320 g adult rats. Denervation (DnX) was performed mechanically stripping all visible renal nerves followed by topical phenol (10%) on the renal artery. Control-sham, MS-sham, control-DnX, and MS-DnX rats were instrumented with catheters in the femoral vein and abdominal aorta. Rats were placed in metabolic cages, connected to swivels, and allowed to recover for 4-5 days. Sodium intake was clamped at 2.8 mEq/day in both groups by combining sodium deficient diet and 24 hr/day 0.9% iv saline infusion (20 ml/day). GFR was determined by plasma clearance of [125I]iothalamate in the conscious state. During baseline conditions, MAP was not different between control-sham and MS-sham rats (99±4 vs 97±2 mmHg, respectively). MAP was reduced in both control-DnX and MS-DnX rats (91±2 mmHg and 83±3 mmHg, p<0.05, respectively) compared with the respective sham group. The reduction in MAP tended to be greater in MS than in control rats (-9±1 and -14±2 mmHg, p=0.074). DnX did not modify GFR in control rats (sham: 3.1±0.1 ml/min vs DnX: 3.5±0.4 ml/min). However, DnX significantly increased GFR in rats exposed to MS (sham: 2.4±0.2 ml/min vs DnX: 3.8±0.4 ml/min, p<0.05). These data support our hypothesis that MS induces increased renal sympathetic tone to reduce GFR in MS male rats, and may contribute to the exacerbated response to hypertensive stimuli observed in MS rats.

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Behaviour of Rats During Selfinitiated Pauses in Feeding and Drinking, and during Periodic Response-Independent Delivery of Food and Water

Quarterly Journal of Experimental Psychology ◽

10.1080/14640748008401839 ◽

1980 ◽

Vol 32 (3) ◽

pp. 459-472 ◽

Cited By ~ 9

Author(s):

T. J. Roper

Keyword(s):

Good Predictor ◽

Temporal Pattern ◽

Baseline Level ◽

Fixed Time ◽

Interreinforcement Interval ◽

Free Access ◽

Periodic Response ◽

Access To Food ◽

Schedule Induction

In Experiment I rats deprived of either food or water were given free access to food or water respectively, and their behaviour was observed during self-imposed pauses in feeding or drinking. In Experiment II food or water were delivered according to fixed-time 30-s and fixed-time 60-s schedules, and the behaviour of the rats was observed during the interreinforcement intervals imposed by these schedules. In both experiments the temporal pattern of those activities that occurred during pauses in eating differed from the pattern of activities occurring during pauses in drinking; and with both food and water the temporal pattern of activities during self-imposed pauses in consummatory behaviour in Experiment I proved a good predictor of the pattern of activities during schedule-imposed interreinforcement intervals in Experiment II. This suggests that intermittent schedules permit the occurrence of those activities that are normally closely associated with the consummatory behaviour in question. In Experiment II certain activities that occurred towards the end of the interreinforcement interval were found to be enhanced relative to baseline level, but there was no enhancement of activities occurring near the beginning of the interval. This is contrary to Staddon's (1977) account of schedule-induced behaviour, and suggests that schedule-induction is not as common as has sometimes been supposed.

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Changes in body composition attendant on force feeding

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.5.965 ◽

1959 ◽

Vol 196 (5) ◽

pp. 965-968 ◽

Cited By ~ 129

Author(s):

Clarence Cohn ◽

Dorothy Joseph

Keyword(s):

Body Weight ◽

Metabolic Pathways ◽

Male Rats ◽

Free Access ◽

Carbohydrate Diet ◽

Experimental Animals ◽

Force Feeding ◽

Feeding Regimen ◽

Ad Libitum ◽

Access To Food

Normal young adult male rats were either force-fed or allowed to eat ad libitum a moderate carbohydrate diet for 3–4 weeks. The force-fed animals were given either the amount of diet consumed by the animals eating ad libitum (pair-fed) or 80% of this amount (underfed). After a 2-week period of observation, we found that the rats eating ad libitum gained 65 gm of body weight, the pair-fed, force-fed 62 gm and the underfed, force-fed 40 gm. On the basis of the water, fat and protein content of the skin, viscera and carcass of control animals killed at the beginning of the feeding regimen and of similar constituents of the experimental animals after 2 weeks of feeding, the composition of the newly formed tissues of the various groups of animals consisted of the following: a) the rat with free access to food—water = 67.8%, fat = 7.8% and protein = 22.4%; b) the pair-fed, force-fed animal—water = 55.5%, fat = 23.6% and protein = 17.7%; c) the underfed, force-fed animal—water = 64.4%, fat = 7.9% and protein = 20.0%. The ratio of calories retained in newly formed tissue to the calories ingested over the 2-week period was 11.9% for the animals eating ad libitum, 20.6% for the pair-fed, force-fed animals and 9.5% for the underfed, force-fed rats. Force feeding appears to change intermediary metabolic pathways in the direction of increased ‘efficiency’ with resultant greater fat deposition.

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Abstract 008: Early Life Stress Induces Renal Pro-inflammatory Immune Responses

Hypertension ◽

10.1161/hyp.66.suppl_1.008 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Carmen De Miguel ◽

Dao H Ho ◽

Analia S Loria ◽

Ijeoma Obi ◽

Jennifer S Pollock

Keyword(s):

Immune Response ◽

Life Stress ◽

Early Life ◽

Maternal Separation ◽

Immune Cell ◽

Early Life Stress ◽

Adult Rats ◽

Activation Markers ◽

Ifn Gamma ◽

Inflammatory Status

We previously reported that maternal separation (MatSep), an animal model of early life stress, sensitizes rats to pro-hypertensive stimuli in adulthood. We hypothesized that MatSep induces a renal pro-inflammatory immune response. Immune cell populations and expression of cytokines were assessed by magnetic bead isolation, FACS analysis, ELISA and RT-PCR in adult male MatSep and normally-reared littermate control rats. Circulating and renal mononuclear or T cell numbers were similar between control and MatSep rats (n=4-11/group, p>0.05). Both groups presented similar percentages of circulating macrophages and T H , T C , and T reg cells (n=4, p>0.05). However, the percentage of circulating B cells was significantly decreased in MatSep rats (23.7±1.2% vs. 20.1±0.7%; n=4, p<0.05). Pro-inflammatory cytokine IL-1Beta was significantly elevated in kidneys from MatSep rats (4.4±0.5 vs. 7.9±1.0 pg/mg prot; n=7-8/group; p<0.05). However, IFN-gamma, IL-6, and IL-4 were not different between control and MatSep rats. To further assess the immune system in MatSep and control rats, we acutely challenged adult rats with lipopolysaccharide (LPS; 2 mg/kg; i.v., 14 h). LPS significantly elevated renal expression of pro-inflammatory chemokine receptors (CCR3, CCR4, CXCR4), cytokines (IFN-gamma, CCL3, CCL4, IL-16), and activation markers (CD40, CD40lg) in MatSep rats (4 to 6 fold increase; n=5/group, p<0.05), suggesting that MatSep induces an exaggerated pro-inflammatory renal immune response to LPS. In conclusion, early life stress induces a renal pro-inflammatory status in adulthood that leads to sensitization to further immune challenges. Funded by P01 HL 69999 to JSP, NIH T32 DK007545 to CDM, F32 HL 116145 to DHH and K99/R00 HL 111354 to ASL.

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