Changes In Ingestive Behavior Research Articles

Chronic liver disease and transplantation — uncovering the role of the liver in ingestive behaviour

The liver is an important metabolic sensor relaying humoral and neural signalling via the brain stem to the hypothalamus. The integration of this information in the higher centres ultimately controls the composition, duration and frequency of nutritional intake. In chronic liver disease, alterations in oxidative metabolism and impairment of the liver's metabolic role may affect changes in ingestive behaviour and nutritional status. In cirrhosis undernutrition is prevalent, whereas following transplantation rapid weight gain is observed. Liver transplant recipients lose all extrinsic hepatic innervation and the absence of humoral and neural responses relayed via hepatic afferents could affect energy homeostasis and contribute to weight gain. Recent in vivo work suggests that patients with hepatocellular cirrhosis have the greatest metabolic disturbances, poorest intakes and nutritional status when compared with patients with cholestatic cirrhosis. Stratification of patients by disease severity had no differential effect. Conversely following transplantation, patients' weights significantly exceed pre-illness values. Evidence suggests that these patients exhibit an energy economy and a shift to increased energy intake from fat. It may be postulated that the liver transplant procedure per se is implicated in development of obesity. The sensing of energy metabolism and food intake are likely to be different in liver cirrhosis and after transplantation. Changes in energy intake and body composition evident in liver cirrhosis and liver transplantation are consistent with its role as an energy sensor.

Diurnal patterns of intake rate by sheep grazing monocultures of ryegrass or white clover

The effects of time of day on the ingestive behaviour of groups of five sheep ( Ovis aries L.), grazing monocultures of ryegrass ( Lolium perenne cultivar ‘Parcour’) or white clover ( Trifolium repens cultivar ‘Kent Wild White’), were measured over periods of 1 h starting at 07:30, 11:30, 15:30 and 19:30 h in August. Grazing behaviour was monitored with an automatic recording system and intake rate was measured by weighing animals before and after grazing. Over the day, for grass and clover respectively, prehension biting rates decreased linearly from 85 to 68 and from 62 to 57 ± 7.4 (SED) bites min −1 and masticating rate increased from 71 to 90 and from 78 to 91 ± 5.6 (SED) chews min −1. Total jaw movements remained constant over the day but were greater on grass than clover ( P < 0.01) at 155 and 145 ± 3.4 (SED) jaw movements min −1. Bite masses also increased linearly from 30 to 51 for grass and from 56 to 107 for clover ± 15.2 (SED) mg dry matter (DM) per bite and differences between grass and clover were significant ( P < 0.001). Intake rates were significantly lower for grass than for clover (2.8 vs. 4.5 ± 0.18 (SED) g DM min −1; P < 0.001). There was an interaction between time of day and herbage species with intake rate increasing over the day from 2.5 to 3.2 and from 3.5 to 5.5 ± 0.67 (SED) g DM min −1 for grass and clover respectively. These changes in ingestive behaviour were associated with diurnal changes in the chemical composition of the two herbages. Herbage DM percentage increased from 07:30 to 19:30 h to a greater extent on grass (15–24%) than clover (12–18%, P < 0.001). WSC increased linearly from 15.6 to 18.3% for grass and from 5.4 to 7.3% of DM for clover ( P < 0.05). Starch content of the herbage also increased linearly from 3.0 to 4.1% for grass and 3.6–8.7% of DM for clover.

Ginsenoside Rg 1 modulates ingestive behavior and thermal response induced by interleukin-1β in rats

Effects of ginsenoside Rg, (Rg i), a major component of panax ginseng, on changes in ingestive behavior and rectal temperature induced by interleukin-1β (IL-1β) were investigated in rats. Intraperitoneal (ip) injection of IL-Iβ suppressed food and water intake and elevated rectal temperature. The suppressive effect of IL-1β on water intake was converted to an increase when 4.0 mM Rg 1 was continuously infused into the third cerebroventricle (ICV) at a rate of 0.966 μl/h. The elevation of rectal temperature induced by IL-1,Q was attenuated by lCV infusion of Rg 1 The feeding suppression caused by IL-1β was unaffected by ICV infusion of Rg 1. These results suggest that sustained ICV infusion of Rg 1 may modulate the effects of IL-1β on ingestive behaviors, i.e., increase in water intake and sustained decrease in food intake, resulting in a lowering of body temperature.

Ondansetron, a selective 5-HT 3 receptor antagonist, reduces palatable food consumption in the nondeprived rat

This study investigated the effects of ondansetron, a selective 5-HT 3 receptor antagonist, on palatable food consumption in nondeprived male rats, under conditions of familiarity. The results showed that ondansetron (3.0–30 μg/kg, i.p.) significantly reduced food intake at each dose tested. The reduction in food intake was due not to a change in the rate of eating but to a reduction in the time spent eating. This, in turn, was due to a reduction in the mean duration of feeding bouts but not due to a change in the frequency of feeding bouts. Hence, the feeding-suppressant effect of ondansetron resulted from a quite specific alteration in the microstructural characteristics of feeding behaviour. In the 60-min observation period, ondansetron did not affect either locomotor activity or rearing, indicating that it did not have general excitatory or behavioural-suppressant effects. Following ondansetron, animals continued to show a typical decline in feeding over time, indicative of the development of within-meal satiety, but the level of feeding was reduced in such a way as to suggest that ondansetron enhances satiety. As a result, as feeding declined, the level of grooming which typically follows the end of feeding, was increased in ondansetron-treated animals. In a supplementary experiment, ondansetron had no effect on deprivation-induced feeding. Present evidence does not allow these data for a 5-HT 3 receptor antagonist to be easily accommodated into the major current hypothesis dealing with serotonergic control of feeding responses. Therefore, the role of 5-HT 3 receptor-mediated changes in ingestive behaviour requires further investigation.

Food deprivation- and palatability-induced microstructural changes in ingestive behavior

The effects of 17 h food deprivation and stimulation by five concentrations (0.05-0.8 M) of sucrose solutions on the licking behavior of rats were investigated. Food deprivation increased the intake of the three lowest concentrations (0.05, 0.1, and 0.2 M) but had no effect on the volume ingested of the two highest concentrations (0.4 and 0.8 M). Food deprivation had no significant effect on the duration of the meals of any of the sucrose solutions; rather it affected the rate of ingestion. In those cases where food deprivation did affect volume intake, it did so by increasing the initial rate of ingestion. Although food deprivation had no effect on the volume ingested of the two strongest concentrations of sucrose, it nevertheless affected the ingestive behavior by increasing the duration of the sustained periods of bursts of licking and decreasing their number. Deprivation also significantly decreased the rate of licking within these sustained bouts of licking. The results indicate that food deprivation can affect the ingestive behavior of rats in ways that are not revealed by measuring volumetric intake alone. The data also support the view that food deprivation increases the palatability of the test solutions.

Ingestive behavior and body temperature of pigeons during long-term cold exposure.

Pigeons well adapted to living in 21 degrees C ambient temperature (T(a)) were continuously exposed to cold T(a) for 6 days (Experiment 1) or 30 days (Experiment 2). The pigeons lived on a 12:12 L:D cycle where they could obtain short access to food and water at any time in the light phase by making 12 keypeck responses. Across the two experiments, the levels of cold exposure were 6 degrees C, 1 degrees C, and 0.6 degrees C. In cold, total daily food intake increased gradually across the first few days of the exposure, and the new level of food intake was inversely related to T(a). The daily ratio of total water drunk to total food eaten averaged approximately 1.3 in 21 degrees C, fell to approximately 1.0 on day 1 of cold exposure, and remained at that level for as long as 30 days. The day-night cycle in core body temperature was not changed by cold exposure. The bimodal temporal pattern of feeding in the light phase, which is characteristic of pigeons in moderate T(a), was preserved in the cold although the absolute level of feeding activity was enhanced. An analysis of the ways individual pigeons achieved total daily food intake by combining a number of feeding episodes with an average amount eaten per episode revealed considerable variation between birds, but a relatively constant feeding style within bird over time. In the colder temperatures used, however, the pigeons all increased the number of feeding episodes per day. The results provide the first detailed analysis of cold-induced changes in ingestive behavior in the pigeon and raise several questions about the behavioral expression of cold-sensitive regulatory processes.

The contribution of gustatory nerve input to oral motor behavior and intake-based preference. I. Effects of chorda tympani or glossopharyngeal nerve section in the rat

Two-bottle intake tests and taste reactivity (TR) tests were used to reveal whether changes in ingestive behavior would follow bilateral section of either the chorda tympani (CT) or the glossopharyngeal (GP) nerve. Rats received two-bottle intake tests to compare 24-h ingestion of water to that of NaCl, MgCl 2, quinine, or sucrose. Prior to each long-term intake test, rats received a 1 min, 1 ml intraoral infusion of the same chemical stimulus. Ingestive and aversive oral motor responses elicited by these 1 ml infusions were videotaped and subsequently analyzed. GP-section did not alter quinine or sucrose preference; overall, preference of MgCl 2 and NaCl was also similar to controls. In contrast, TR tests in GP-sectioned rats revealed that most quinine, MgCl 2 and NaCl stimuli elecited significantly fewer aversive oral motor responses. In addition, the latency of aversive responses to these 3 chemical stimuli was increased for these rats. Intake-based preference tests failed to show any difference between rats with CT nerve section and controls. In TR tests, however, CT-sectioned rats displayed significantly fewer ingestive oral motor responses to NaCl, MgCl 2, and quinine than controls. Neither sucrose intake nor sucrose-elicited TR were altered by CT or GP nerve section. This report confirms the failure of long-term intake tests to uncover behavioral deficits following the section of gustatory nerves. In contrast, the use of a different behavioral test makes clear for the first time that gustatory nerve section has dramatic consequences on ingestive behavior. The examination of taste elicited oral motor behaviors reveals a coherent and nerve specific pattern of neurological deficit following peripheral nerve section.

Dopaminergic regulation of feeding behavior: I. Differential effects of haloperidol microinfusion into three striatal subregions

In the present study, the role of dopaminergic mechanisms within different striatal subregions in feeding behavior was examined in food-deprived (19 h) rats. Specifically, the dopamine (DA) antagonist haloperidol (0, 0.025, 0.25, 2.5 μg/0.5 μl) was infused bilaterally into the nucleus accumbens (N.Acc), the ventrolateral striatum (VLS), or the dorsolateral striatum (DLS), and a microanalysis of ingestive behavior and spontaneous motor behavior was carried out. When infused into the N. Ace, haloperidol increased feeding duration, food intake, and the average duration of a feeding bout. Locomotor activity and drinking behavior were reduced by N.Acc. haloperidol infusion. In contrast, feeding was attenuated when haloperidol was infused into the VLS. Drinking and locomotion were unaffected. Few changes in ingestive behavior were noted following DA-antagonist treatment of the dorsolateral site. It is hypothesized that DA transmission in the N.Acc. normally facilitates switching between different competing behaviors, that the VLS is critical for control of oral motor mechanisms, and that the DLS is minimally involved in modulating ingestive behavior.

Changes in Ingestive Behavior Induced by Intracranial Injection of Spermine.

Effect of intracranial injection of spermine on feeding and drinking behavior was studied in rats. A significant and long-term suppression of feeding and drinking behavior appeared when 30 nmol/hemisphere of spermine was bilaterally injected into the lateral hypothalamic area, substantia nigra or ventral noradrenergic bundle. Micro-injected spermine into the medial amygdaloid nucleus produced a weak and short-time but significant suppression of ingestive behavior. On the other hand, a significant increase in feeding and drinking behavior was observed when spermine was injected into the ventromedial hypothalamic nucleus. These results suggest that spermine inhibits neuronal activity of all the brain regions studied here.

Effects of β-funaltrexamine on ingestive behaviors in the rat

The effects of β-funaltrexamine (β-FNA), an irreversible μ-opioid receptor antagonist, were determined on water and food intake of non-deprived rats. Intracerebroventricular administration of 1.25 or 2.5 μg of β-FNA did not affect drinking or eating. However, 5.0 μg first transiently increased food intake and then reduced both water and food intake for at least 72 h. Locomotor activity was unaffected by 5.0 μg of β-FNA; thus, changes in ingestive behavior were not a secondary consequence of drug-induced behavioral stimulation or depression. The early increase in food intake may be due to the short lived and reversible κ-agonist activity of β-FNA. On the other hand, selective blockade of μ-opioid receptors appears sufficient to reduce the intake of water and food.

Increased food intake after opioid microinjections into nucleus accumbens and ventral tegmental area of rat

The nucleus accumbens (ACC) and ventral tegmental area (VTA), two areas believed to subserve reinforcement and increases in locomotor activity produced by opioid microinjections, were examined for their involvement in opioid-produced changes in ingestive behavior. Opioids were infused bilaterally, and food and water intakes were measured for 1 h thereafter. Different morphine doses were administered and, with placements in globus pallidus and lateral ventricles as controls for diffusion, it was found that only ACC and VTA microinjections (0.1–10 nmol) produced dose-related increases in food intake. In both the ACC and VTA low doeses of morphine also produced increases in water intake while in ACC high doses produced a decrease. Administration of morphine and an enkephalin analogue (Tyr- d-Met-Gly-Phe(4-NO 2)-Pro-NH 2) at different depths in the ACC indicated that the increase in food intake occurred at a site separate from that of the decrease in water intake. Using levorphanol, dextrorphan and morphine mixed with naloxone, it was shown that the effects were due to activation of opioid receptors. Additional experiments demonstrated that food intake is increased by ACC morphine under different levels of deprivation, with different times of testing and with availabilities of various goal objects in addition to food. The effect also did not appear to under go development of tolerance or sensitization. It was concluded that there are sites in the ACC and VTA where increased activity of endogenous opioid peptide systems reliably increase food intake and it was hypothesized that these sites may contribute to changes in ingestive behavior after systemic morphine administration. Also, together with other effects produced by opioid by opioid microinjections into the ACC and VTA, the present findings suggest that increased opioid activity in these areas produce a pattern of behaviors similar to that produced in normal animals by food conditioned stimuli.

Brain and peripheral opioid peptides after changes in ingestive behavior.

The levels of dynorphin, alpha-neoendorphin and beta-endorphin immunoreactivity (ir-DYN, ir-alpha-NEO, ir-beta-E) were measured in the brain, pituitary and gut of rats subjected to a variety of manipulations. Water deprivation caused an increase in the ir-DYN and ir-alpha-NEO content in the hypothalamus and a decrease in the neurointermediate (NI) lobe of the pituitary. The ir-beta-E level decreased in the hypothalamus and anterior lobe of the pituitary, while it increased in the NI-pituitary. Food deprivation, as well as chronic fenfluramine (10-20 mg/kg) treatment increased, while acute muscimol (0.5 micrograms/10 microliter) treatment decreased the ir-beta-E, but not ir-DYN or ir-alpha-NEO content in the hypothalamus. The anterior pituitary content of ir-beta-E was increased after food deprivation and decreased after chronic fenfluramine treatment. However, the ir-DYN and ir-alpha-NEO contents in the duodenum were markedly increased after food deprivation, while chronic fenfluramine treatment led to a dramatic decrease in the ir-DYN content. These results suggest that the levels of opioid peptides in the brain, pituitary and gut may be differentially and independently affected by alteration of the ingestive behavior.

Changes in ingestive behavior, serum glucose and free fatty acids concentrations in rats following intracerebroventricular injection of spermine.

We examined the changes in ingestive behavior, serum glucose (Glc) and free fatty acids (FFA) concentrations in male rats following intracerebroventricular (i.c.v.) injection of spermine (SPM). In satiated rats, over a 53.3 nmol of SPM suppressed feeding and drinking behavior in a dose-dependent manner. The median suppressive dose was 90.8 nmol for feeding behavior and 68.3 nmol for drinking behavior. Spermidine also suppressed ingestive behavior but the potency was appreciable weak compared to that of SPM, and the occurrence of the maximal suppression was observed 2-3 days later than that of SPM. The most significant anorexia and adipsia induced by SPM appeared between 16 and 36 hr after i.c.v. administration. SPM (180 nmol) produced a biphasic increase in serum Glc concentration. The 1st peak was at 1 hr and the other peak was 24 hr after the dosing. The same dose of SPM elevated serum FFA concentrations gradually, and the maximal increase appeared 24 hr after the injection. As less than a 120 nmol dose of SPM did not alter serum Glc and FFA concentrations, there seems to be no causal relation between SPM-induced anorexia, and changes in serum Glc and FFA concentrations. Nevertheless, the findings that a very small dose of SPM produced anorexia and adipsia support the possibility that SPM may play some functional role in the brain.

CHANGES IN INGESTIVE BEHAVIOR, SERUM GLUCOSE AND FREE FATTY ACIDS CONCENTRATIONS IN RATS FOLLOWING INTRACEREBROVENTRICULAR INJECTION OF SPERMINE

AbstractWe examined the changes in ingestive behavior, serum glucose (Glc) and free fatty acids (FFA) concentrations in male rats following intracerebroventricular (i.c.v.) injection of spermine (SPM). In satiated rats, over a 53.3 nmol of SPM suppressed feeding and drinking behavior in a dose-dependent manner. The median suppressive dose was 90.8 nmol for feeding behavior and 68.3 nmol for drinking behavior. Spermidine also suppressed ingestive behavior but the potency was appreciably weak compared to that of SPM, and the occurrence of the maximal suppression was observed 2–3 days later than that of SPM. The most significant anorexia and adipsia induced by SPM appeared between 16 and 36 hr after i.c.v. administration. SPM (180 nmol) produced a biphasic increase in serum Glc concentration. The 1st peak was at 1 hr and the other peak was 24 hr after the dosing. The same dose of SPM elevated serum FFA concentrations gradually, and the maximal increase appeared 24 hr after the injection. As less than a 120 nmol dose of SPM did not alter serum Glc and FFA concentrations, there seems to be no causal relation between SPM-induced anorexia, and changes in serum Glc and FFA concentrations. Nevertheless, the findings that a very small dose of SPM produced anorexia and adipsia support the possibility that SPM may play some functional role in the brain.

An analysis of ingestive behaviour and activity of cattle under field conditions

A modified vibracorder was used to record the time spent by cattle in grazing and ruminating under field conditions for 24-h periods in autumn and winter during 3 consecutive years. An unmodified vibracorder device was also used to obtain concurrent information about walking, loafing and resting time. Three major influences were examined: the size of the field, the seasonal changes of grass availability and the weather. The time spent walking was correlated ( r = 0.92) to that of grazing and the time of their onset (and reset) was correlated ( r = 0.89) to the corresponding times of sunrise (and sunset). An excess of time spent walking compared with that of grazing was found in both the 0.5 and 3 ha fields but the circadian pattern of grazing was disrupted when cattle were restricted to the small area. When the cows were turned into the large field both walking and loafing were transiently increased due to the novelty of the environment. Then the time spent walking but not loafing decreased from November to March in relation with the lower amount of grass available. A further reduction in time spent walking was observed for windy weather. It is concluded that the size of the field and weather interact with the circadian patterns of both walking and grazing while the seasonal changes in ingestive behaviour are due to the amount and quality of grass available.

Synergistic action of p-chloroamphetamine and fluoxetine on food and water consumption patterns in the rat

The distribution of eating, drinking and body weight changes during the 24 hr day were examined following brain 5-HT depletion with p-chloroamphetamine (PCA). Following a baseline period, measurements of food and water intakes and body weights were recorded 1, 2, 3, 6, 12, 20 and 24 hr following PCA, 5.0 mg/kg, or saline. Other animals were pretreated with fluoxetine, 10.0 mg/kg, prior to either PCA or saline in an attempt to block the PCA effects. The results indicate acute hypophagia, hypodipsia, and body weight losses. These decreases were not influenced by the time of day when PCA was administered. Pretreatment with fluoxetine enhanced rather than blocked these effects. No long term changes in ingestive behavior were seen. These results are discussed with respect to the possible role of 5-HT in the control of ingestive behavior.

Changes in ingestive behavior following interruption of a noradrenergic projection to the paraventricular nucleus: Histochemical and neurochemical analyses

Histochemical investigation of the paraventricular nucleus (PVN) identified the tractus filiformis lateralis (TF) as a major noradrenergic preterminal pathway to the PVN. Bilateral knife cuts transecting the TF resulted in a discrete deafferentation of 56% of the noradrenergic input to the PVN region. TF transection also resulted in hypophagia and hypodipsia during the first four days after surgery. A marked hyperdipsia developed between postoperative Days 11 and 13 and persisted until sacrifice on Day 17. The results suggest that the TF contains a noradrenergic system which innervates the PVN and is involved in mediation of ingestive behaviors.

A note on changes in ingestive behaviour of sheep following shearing

The grazing behaviour and herbage intake of sheep grazing at four stocking rates were recorded before and after shearing in winter in Southern Australia. Following shearing, grazing time was reduced but intake of organic matter per hour increased at all stocking rates even though the amount of feed available was very low at the highest stocking rate. Energy balance was maintained at the three lowest stocking rates. At the highest stocking rate, the sheep were in poor condition and spent more time sheltering; time spent grazing was greatly reduced, energy balance was not maintained and 40% of the sheep died.

Ingestion affected by the oral environment: The role of gustatory adaptation on taste reactivity in the rat

Three experiments were performed to determine (1) the time course of changes in ingestive behavior associated with oral infusion of taste substances, and (2) the possible role of changes in the tonic chorda tympani response in the behavioral effect of oral infusion. Experiments 1 and 2 examined 2 different procedures with a variety of sapid solutions to detect alterations in ingestion following oral adaptation. Decrements in Na-saccharin licking were found over a 2-hr period of continuous Na-saccharin stimulation suggesting that gustatory adaptation in the rat extends over a considerable time period and that the effect of the infusion was to alter the incentive motivation properties of the sapid substance. Experiment 3 sought an altered tonic responsivity of the chorda tympani nerve which might correlate with the decrement in ingestion seen in Experiment 2. No evidence of a neural decrement over a 2-hr time was found and it was concluded that central processes were probably involved in the behavioral adaptation found in the second experiment.

The Development of Social Behavior Patterns in the Mouse, in Relation To Natural Periods 1)

1. This paper consists of a descriptive study of the post-natal behavioral development of the house mouse, with particular emphasis on its social aspects. 2. Observations were made on ten litters, including 60 mice from four different inbred strains, up to the age of 30 days. Nine litters were raised in transparent laboratory mouse boxes, and the tenth was raised in a larger box with a more complex environment. 3. Important developmental changes which affect the nature of social relationships were found at 4 days, 12 days, and approximately 25 days. On this basis the early development of the mouse was divided into four natural periods. 4. These periods are described in detail from the viewpoint of sensory, motor, and psychological capacities, and the appearance of important patterns of social behavior. 5. During the Neonatal Period (I) the mice are naked and largely helpless, and the predominant activities are ingestive and contactual behavior. There is no reaction to sound or sight, nor an indication of learning capacity. 6. The Transition Period (II) is characterized by rapid development of sensory, motor and psychological capacities which provide the basis for future change in social behavior patterns. The period is marked by the appearance of epimeletic behavior (grooming) and an increase in investigative behavior. Other social behavior patterns remain much as before. 7. The Socialization Period (III) begins with all sense organs functional, so that the animal is for the first time in complete contact with the social environment. Motor development is rapid, and the animals give evidence of great sensivity to frightening stimuli. All the characteristic social behavior patterns of adults appear in some form during this period, and at its end one of the last neonatal patterns, nursing, disappears. The dominant behavior patterns are investigative and epimeletic (grooming). 8. During the Juvenile Period (IV) fighting behavior appears, and its end is marked by the first appearance of adult sexual behavior. 9. Certain physiological changes are correlated with overt changes in behavior. Reactions to electroshock change at 4 and 12 days. Changes in the growth curve occur with changes in ingestive behavior, which in turn is correlated with the opening of the eyes at about 12 days. 10. There is evidence that reactions to sound appear early in the Transition Period, but the startle reaction does not appear until near its close. 11. Further study is needed of the development of the capacity for simple associative learning, which on present evidence may appear early in the Transition Period. 12. When the mouse is compared with other forms it is found that the order of behavioral events varies considerably between different species, and that the order appears to be correlated with the nature of social organization typical of the species. 13. The development of behavior in the mouse is discussed with reference to possible critical periods in the development of social relationships.