Duration Of Water Deprivation Research Articles

Serotonin modulates the dehydration-induced changes in tolerance for bitter water

Drinking behavior is regulated by endogenous factors such as the hydration condition of animals and exogenous factors such as the taste of ingested fluids. These factors have been suggested to interact with each other via serotonergic (5-HT) signaling to regulate drinking behavior. In the present study, we examined how dehydration affects the intake of bitter water, which suppresses drinking behavior, via 5-HT signaling. Water deprivation increased water intake for 1h, depending on the duration of water deprivation. The intake of 1mM quinine, which is a bitter tastant, was lower than that of water in mice deprived of water for 24h but not 48h. We next examined the involvement of the dorsal raphe nucleus (DRN) and median raphe nucleus (MRN), which contain a large population of 5-HT neurons, in changing tolerance for quinine intake after water deprivation. The intake of quinine following water deprivation for 24h, but not 48h, increased the number of tryptophan hydroxylase-positive neurons expressing c-Fos in the DRN, but not in the MRN. Moreover, administration of paroxetine, a selective serotonin reuptake inhibitor, decreased the intake of quinine solution, but not water, in mice deprived of water for 48h, indicating that paroxetine treatment restored the aversion to quinine. These results suggest that unresponsiveness of 5-HT neurons in the DRN may be involved in the dehydration-induced increase in tolerance for bitter water.

Measuring thirst in broiler chickens

AbstractFreedom from thirst has been long considered of paramount importance for animal welfare, however a feasible and sensitive animal-based indicator to assess thirst, on-farm or at-slaughter, is not available. In this study, voluntary water consumption over time was investigated and validated as a non-invasive behavioural parameter for assessing thirst in broiler chickens. Thirty-two groups of four broilers were used in this study and the effect of three factors on water consumption from a test drinker was investigated: duration of water deprivation (0, 6, 12, or 24 h); familiarity with the test drinker, and age (35 or 37 days). Water consumption was measured after 30, 60, 90 and 120 min following the deprivation period. Water consumption increased with the length of the deprivation period and was greater in birds that had been habituated to the test drinker. The effect of familiarity was smaller for 24-h deprived groups compared to 6- and 12-h deprived groups. When birds were habituated to the drinker, they started to drink sooner than when the drinker was new. These findings illustrate the potential of simple, animal-based measures, such as water consumption over time to assess thirst in chickens and this behavioural test may form the basis of an on-farm test that could be included in integrated animal welfare assessment schemes.

Effects of Various Durations of Water Deprivation on Performance of Weaner Rabbits in a Sub-Humid Environment

2 Abstract: An experiment was conducted to assess the effects of various duration of water deprivation on performance of weaner rabbits in a sub-humid environment. Forty eight (48) nine-week old weaner rabbits of mixed breed and sex with an average initial weight of 622 ± 0.12g were used for the study which lasted 56 days There were four watering treatments such that water supply was restricted for 0, 6, 12 or 18 hours corresponding to 24, 18, 12 or 6 hours of access to water per day respectively. The rabbits were randomly assigned based on initial live weight and sex to the four watering treatments in a completely randomized design. Free water intake decreased linearly and significantly (P 0.05) on daily feed intake. There were significant (P<0.05) decreases in live weight gains, feed efficiency and water to feed ratio with increase in duration of water deprivation respectively. Mortality rate of about 16 and 33% were recorded among rabbits groups deprived of water for 12 and 18 hours per day respectively. Results of the study showed that for optimum growth performance, weaning rabbits should have access to free drinking water for a minimum period of 12 hours in a day. Key word: Water deprivation, weaner rabbits, sub-humid environment

Short Communication: Effect of increasing duration of water deprivation on feed intake, feed digestibility and body weight gain of Nganda sheep

Short Communication: Effect of increasing duration of water deprivation on feed intake, feed digestibility and body weight gain of Nganda sheep

Effect of partial water deprivation on the performance and carcass characteristics of broler chickens exposed to selected durations of water deprivation in the humid tropical environment

A study was conducted to assess the effects of partial water deprivation on the biologic performance and carcass qualities of broiler chickens raised in a humid tropical environment. There were 2 experiments involving the use of 280 and 500 broiler chickens of mixed sexes respectively. These birds were raised to 4 weeks of age and then subjected to selected durations of water deprivation treatments which lasted for 2 and 5 weeks respectively. Water deprivation exposure had no significant effect (P>0.05) on body weight, weight gain, feed intake, feed conversion ratio and mortality following 2 weeks of treatment in the first experiment. However, in the second experiment, when the birds were exposed to longer period of water deprivation (5 weeks), body weight and water consumption were significantly affected (P

Neuroanatomy of the panic-respiration system

Drinking behavior is regulated by endogenous factors such as the hydration condition of animals and exogenous factors such as the taste of ingested fluids. These factors have been suggested to interact with each other via serotonergic (5-HT) signaling to regulate drinking behavior. In the present study, we examined how dehydration affects the intake of bitter water, which suppresses drinking behavior, via 5-HT signaling. Water deprivation increased water intake for 1 h, depending on the duration of water deprivation. The intake of 1 mM quinine, which is a bitter tastant, was lower than that of water in mice deprived of water for 24 h but not 48 h. We next examined the involvement of the dorsal raphe nucleus (DRN) and median raphe nucleus (MRN), which contain a large population of 5-HT neurons, in changing tolerance for quinine intake after water deprivation. The intake of quinine following water deprivation for 24 h, but not 48 h, increased the number of tryptophan hydroxylase-positive neurons expressing c-Fos in the DRN, but not in the MRN. Moreover, administration of paroxetine, a selective serotonin reuptake inhibitor, decreased the intake of quinine solution, but not water, in mice deprived of water for 48 h, indicating that paroxetine treatment restored the aversion to quinine. These results suggest that unresponsiveness of 5-HT neurons in the DRN may be involved in the dehydration-induced increase in tolerance for bitter water.

Expression of Fos immunoreactivity in rat brain during dehydration: effect of duration and timing of water deprivation

Water deprivation induces expression of the immediate early gene c- fos in specific brain regions, most likely as a result of the activation of cells that are responsive to changes in osmolality and/or blood volume. We hypothesized that the magnitude of c- fos expression would be a function of both the duration of water deprivation and the time of day at which the deprivation started. This study was designed to examine the pattern of Fos-like immunoreactivity (FLI) following water deprivation in rats under normal light/dark conditions (nLD) and reverse light/dark conditions (rLD). Rats were deprived of water but not food either for 0, 5, 16, 24 or 48 h. As expected, hematocrit ratio (HCT), osmolality (OSM), plasma renin activity (PRA) and weight loss increased as a function of duration of water deprivation. In non-deprived rats (0 h), very little FLI was observed in most brain regions. The number of cells showing FLI increased with duration of water deprivation in the supraoptic nucleus (SON), paraventricular nucleus (PVN), organum vasculosum laminae terminalis (OVLT), median preoptic nucleus (MnPO) and subfornical organ (SFO) in both nLD and rLD conditions. However, the pattern of FLI differed between nLD and rLD conditions. Compared to corresponding nLD groups after 5 or 24-h water deprivation, rLD groups had significantly more FLI in SON and PVN, and higher PRA and HCT. Also, weight loss and FLI in the MnPO were greater after 5 h, and FLI in the SFO was greater after 24 h under rLD compared to nLD conditions. Our findings indicate that the magnitude of c- fos expression, and change in weight and plasma parameters were a function of both the duration of water deprivation and the time of day at which the deprivation started. This may result from ingestion of food early in the deprivation periods during the rLD tests, thus producing greater change in osmolality and blood volume.

Neurones in the median preoptic nucleus projecting to the supraoptic nucleus are sensitive to hemodynamic changes and increase of plasma osmotic pressure in the rat

Water deprivation induces expression of the immediate early gene c-fos in specific brain regions, most likely as a result of the activation of cells that are responsive to changes in osmolality and/or blood volume. We hypothesized that the magnitude of c-fos expression would be a function of both the duration of water deprivation and the time of day at which the deprivation started. This study was designed to examine the pattern of Fos-like immunoreactivity (FLI) following water deprivation in rats under normal light/dark conditions (nLD) and reverse light/dark conditions (rLD). Rats were deprived of water but not food either for 0, 5, 16, 24 or 48 h. As expected, hematocrit ratio (HCT), osmolality (OSM), plasma renin activity (PRA) and weight loss increased as a function of duration of water deprivation. In non-deprived rats (0 h), very little FLI was observed in most brain regions. The number of cells showing FLI increased with duration of water deprivation in the supraoptic nucleus (SON), paraventricular nucleus (PVN), organum vasculosum laminae terminalis (OVLT), median preoptic nucleus (MnPO) and subfornical organ (SFO) in both nLD and rLD conditions. However, the pattern of FLI differed between nLD and rLD conditions. Compared to corresponding nLD groups after 5 or 24-h water deprivation, rLD groups had significantly more FLI in SON and PVN, and higher PRA and HCT. Also, weight loss and FLI in the MnPO were greater after 5 h, and FLI in the SFO was greater after 24 h under rLD compared to nLD conditions. Our findings indicate that the magnitude of c-fos expression, and change in weight and plasma parameters were a function of both the duration of water deprivation and the time of day at which the deprivation started. This may result from ingestion of food early in the deprivation periods during the rLD tests, thus producing greater change in osmolality and blood volume.

Odor-Based Runway Performance of Rats as A Function of Type of Reinforcer and Multiple Deprivation Conditions

Two experiments examining the development of odor-based double-alternation patterning under concurrent food and water deprivation, but food versus water reinforcement, are reported. In both experiments patterning was established only by animals receiving food reinforcement. Shifting type of reinforcer (i.e., food to water, and vice versa) resulted in an immediate and pronounced change in performance (Experiment 1). Increasing the duration of water deprivation (Experiment 2) produced an increase in general performance level, but did not result in the development of patterning by water-reinforced animals. These results would appear to be supportive of an ethologically based interpretation, such as optimal foraging theory.

Daily behavioral manipulation increases the total immunoreactive serum neurophysin concentrations irrespective of the duration of water deprivation in rats.

The daily training of rats in a two-compartment test box is sufficient to involve an increase in the total immunoreactive serum neurophysin concentrations when compared to totally undisturbed controls. Furthermore, this training is capable of masking the differences in neurophysin concentrations usually seen in unmanipulated rats after different durations of water deprivation. To interpret these high neurophysin levels, we speculatively suggest the existence of hypothalamic compensatory biosynthetic mechanisms which would induce the formation and/or the release of neurophysin pools under stress. Additionally, we propose that some subnuclei of the paraventricular nuclei are the neuroanatomical substratum of these mechanisms.

Facilitation or impairment of learning by d-amphetamine as a function of stimuli.

Water-rewarded spatial discrimination learning was studied in rats injected with either d-amphetamine sulphate or physiological saline 15 min prior to the first of two training sessions. The effect of a light which functioned as a reward and/or as a distraction in the testing situation was examined. Amphetamine was found to facilitate learning by enhancing the reward value of light onset and also to impair learning by enhancing the distraction of light onset. The effects of amphetamine were found to interact with the duration of water deprivation preceding the first training session. Factors responsible for the controversy concerning amphetamine's influence on learning were implicated.

The effects of water and food deprivation on the heart rate of rats

The heart rate (HR) of male hooded rats was recorded in a nonhome cage for three weeks. Then they were deprived of water (Group 1, N = 6) or food (Group 2, N = 6) up to 96 h. HR was recorded at 8 h, 24 h, 48 h, 72 h, and 96 h of deprivation. The HR of Group 1 increased linearly with the duration of water deprivation, while that of Group 2 showed an inverse U-shaped function. These functions suggest that HR is influenced by two concomitant conditions: dehydration and metabolism.

Water intake of the rat with food present following different durations of water deprivation.

burk, & Rollins, 1966), the intake function might be different when food is present during the drinking period. The experiment reported here explored this possibility. The procedure followed that of the previous study, with the exception that food was present during the drinking period. Briefly, 60 naive male albino rats were matched into 10 water-deprivation conditions on the basis of mean daily water intake during an ad Libitum base period. The deprivation conditions were: 0, 12, 24, 36, 48, 72, 96, 120, 144, and 168 hr. A 2-hr. drinking period for all Ss was set from 7:00 AM to 9:00 AM on the last day of an %day deprivation period. Water was removed from the 6 Ss in each group at the appropriate number of hours before the common drinking period. All Ss had access to food during deprivation; food also was available during the drinking period. The water-intake function obtained was similar in shape to the function reported earlier (Dufort & Abrahamson, 1966); intake increased up co 48 hr. deprivation and was stable thereafter with only minor upward fluctuations at 96 hr. and 168 hr. Analysis of variance yielded an effect of length of deprivation (P < .001). Duncan's test showed that intake did not vary significantly for groups deprived for 48 hr. or longer, but significant differences (P < .05) were found among groups deprived for 0, 12, 24, and 36 hr. and those deprived for 48 hr. or longer. The results also showed an approximately 20% greater intake than was found earlier. Thus, while the asymptote of the intake function was reached at 26 to 27 ml. in the earlier srudy, the asymptotic intake was in the 30 to 31 ml. range in this study. These resulcs support other evidence showing greater water intake in the presence of food; the shape of the intake-deprivation function is not affected by presence or absence of food.

Water intake of the rat as a function of duration of water deprivation.

Water intake in a 2-hr. period was measured for groups of rats deprived of water either 0, 12, 24, 36, 48, 72, 96, 120, 144, or 168 hr. The intake function appeared to reach a maximum value at 48 hr., suggesting that intake is not a useful measure of the effects of long durations of water deprivation.