Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Appetitive Behavior”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
PubMed1986

Food-search behavior and its relation to the central excitatory state in the genetic analysis of the blow fly Phormia regina.

Dethier (1957) described an aspect of food-search behavior in Phormia regina as the blow fly dance. A hungry fly walks in relatively straight lines with its proboscis retracted until it encounters food (sucrose). After ingesting even a small amount of sucrose, the fly begins making frequent, tight turns, flexes its front tarsi to bring more chemosensory hairs into contact with the substrate and repeatedly extends and retracts its proboscis. Like the central excitatory state (CES), which causes an increase in proboscis extensions to water when a fly is stimulated with sucrose, the dance lasts longer in hungrier flies or with higher sucrose concentrations. It was considered that dance behavior might be an ethologically relevant manifestation of CES. In order to test this hypothesis, dance duration in lines selected for high- and low-CES levels was measured. As predicted, flies from the high-CES line danced longer than those from the low-CES line, and the CES-dance correlation in individual flies was high. This phenotypic correlation disappeared in the F2 generation of a cross between the high- and low-CES lines, a result indicating that the observed variations in CES and dance duration were not caused by the same set of genes. Further characterization of the underlying genetic system showed that several linked autosomal genes with digenic epistatic interactions and a complex pattern of maternal inheritance were responsible for the difference in dance durations between the high- and low-CES lines.

Animals↗
PubMed1994

Effects of neonatal decortication on the social play of juvenile rats.

The effects of radical neonatal decortication on the social play of juvenile rats, as well as the effects of neonatal ablation of frontal or parietal cortex, were examined in this series of experiments. When total decorticates were tested in like-lesioned pairs, the frequency of pinning was reduced by about 50% and their average pin durations were shorter. Nevertheless, the play of decorticates appeared essentially normal in general appearance, and did not differ from controls in a measure of overall play vigor using an electronic activity platform. Further, there were no differences in pin frequencies when controls and decorticates were paired together in cross-lesion testing. Separate tests of play solicitation behaviors did not detect any differences between controls and decorticates suggesting that play motivation was essentially intact after decortication. No deficits in pinning resulted from frontal ablations; however, pin durations were shorter in like-lesion testing. In cross-lesion testing, there was an increase in dorsal contacts and a trend toward shortening of pin durations. Parietal aspirations resulted in a 65% reduction in pin frequency, without substantially altering dorsal contacts. Anesthetization of the anterior surface of the animal's back with xylocaine reduced pinning in controls but eliminated pinning in parietals. Although the results generally indicate little participation of the neocortex in the instigation of rough-and-tumble play, the reliable numerical changes that were observed may be explained by apparent motor changes as well as reduced somatosensory sensitivity.

Aging↗
PubMed1997

The work costs of earning food as a determinant of patch leaving.

Foraging theorists have long emphasized the role of the energy (work) costs of food items on foraging behavior. However, few experiments have measured this variable or demonstrated that animals are indeed sensitive to work costs. Experiment 1 assessed whether rats (Long-Evans) can use the work costs of food to determine whether a food patch is exhausted. Rats performed a fixed amount of work for each food item (fixed-work [FW] schedule), but food was withheld unpredictably to simulate sudden patch depletion. It was found that rats left patches only when the work costs of unsuccessful searches (giving-up work) exceeded the prevailing work costs of food. The time and response costs of unsuccessful food searches (giving-up time and giving-up responses) were not predictive of patch leaving. Experiment 2 showed how rats regulated work in this paradigm by examining the role of exteroceptive stimuli connected with fulfilling the FW schedule.

Animals↗
PubMed1994

Internal clock and memory processes in animal timing.

Temporal control of behavior was investigated within the framework of an internal clock model. Pigeons were exposed to signaled fixed-interval 30-s trials mixed with extended unreinforced (baseline) trials. On unreinforced break trials, the signal was interrupted for a period of time after trial onset. In Experiment 1, comparisons between the peak time obtained on baseline and on break trials produced peak time shifts that were longer than those expected if the clock had stopped during the break but shorter than if the clock had reset. In Experiment 2, systematic manipulations of duration and location of breaks produced peak time shifts that were nonlinear functions of break duration and that varied linearly with break location. The obtained peak times were more consistent with a continuous memory decay model than with the stop-retain or the reset hypotheses.

Animals↗
PubMed1980

Autoshaping and food acquisition in mice: a genetic analysis.

A genetic analysis was undertaken for a number of quantitative behavioral characters that were hypothesized to be components in a generalized feeding pattern. These measures included open-field activity, rate of food ingestion, and rate of development of an autoshaped operant response. Four strains of inbred laboratory mice were used as subjects in a diallel cross design. Standard analytical procedures, including the Hayman analysis of variance and the Jinks variance-covariance diagram, were used to interpret the data. The results were evaluated in terms of the contribution of fitness provided by each of the measured characters. It is concluded that both the various open-field measures and the food-consumption measure were of some importance in the evolutionary history of the mouse. The autoshaping measures, on the other hand, showed a pattern of inheritance that differed from the other measures and offered no clear interpretation of their evolutionary significance.

Animals↗
PubMed2003

Increased water intake by rats maintained on high NaCl diet: analysis of ingestive behavior.

To determine the temporal relation between the ingestion of dry food containing 8% NaCl and the increased daily consumption of water that occurs when rats eat this diet, rats were placed in specially designed cages linked to microprocessors that allowed the continuous monitoring of food and water ingestion. The increase in water intake was found to result from increases both in number and size of individual drinking bouts. Approximately 75% of the water intake was consumed in drinking bouts that occurred less than 5 min after feeding. Indeed, rats rarely consumed 8% NaCl diet without also drinking water in the same ingestive episode, and the volume of water they drank was proportional to the food intake in that episode. These and other observations suggest that ingestion of the high salt diet stimulated thirst rapidly. As such, they are consistent with previous reports that visceral osmoreceptors (or Na(+)-receptors) detect osmolytes passing through the gastrointestinal tract and provide an early stimulus of thirst in rats that precedes large increases in systemic plasma osmolality.

Animals↗
PubMed1993

Experience with milk and an artificial nipple promotes conditioned opioid activity in the rat fetus.

Milk promotes activity in the kappa opioid system of the rat fetus and reduced responsiveness in a behavioral bioassay of cutaneous sensitivity. In this study, E20 rat fetuses were presented with an artificial nipple (CS) and intraoral infusions of milk (US) to condition opioid activity. Paired presentations of the CS and US resulted in conditioned changes in perioral cutaneous sensitivity, which was not evident in groups exposed to the CS alone, US alone, or explicitly unpaired presentations of US and CS. Selective opioid antagonists administered between conditioning and testing revealed that reexposure to the nipple resulted in activation of the endogenous opioid system. The nipple promoted activity at mu, not kappa, opioid receptors. Conditioned opioid activity to an artificial nipple in the fetus, which lacks experience with milk or other suckling stimuli, implies that conditioned changes in the endogenous opioid system of the newborn rat may develop quickly during the first suckling episodes.

Animals↗
PubMed1984

Food-motivated behavior in rats with cortico-basomedial amygdala damage.

Twelve rats with amygdala damage (CBM) and 20 sham-operated controls were tested in several food-related situations. The CBM rats showed a longer latency to eat than controls in a novel environment due to more pronounced exploration. In the competition for food, CBM rats lost 85% of encounters with controls. Immediately after the contest, when allowed to eat singly, CBM rats displayed a higher persistence of alimentary responses to an emptied cup than did controls, presumably because they experienced more losses in the food competition. Both groups were equally able to overcome obstacles on the way to food, which suggests similar alimentary motivation. The only direct indication of a lowered responsiveness to hunger in CBM rats was 24-hr-fasting-induced hypophagia. The results of this study indicate the involvement of the cortico-basomedial amygdaloid region in the control of relations between alimentary and other motivations. The contribution of eventual changes of food motivation in the postoperative alteration of this balance is discussed.

Amygdala↗
PubMed1997

Effects of ibotenic acid-induced loss of neurons in the medial prefrontal cortex of rats on behavioral vigilance: evidence for executive dysfunction.

Rats were trained in a previously validated task for the assessment of sustained attention, or vigilance. This task required the animals to discriminate between signals of variable lengths and non-signal events by making an appropriate lever press. The performance of sham-lesioned animals in this task was characterized by a signal-length dependent number of hits. Also, approximately 70 percent of the non-signals were correctly rejected. Ibotenic acid-induced lesions of the medial prefrontal cortex decreased the relative number of hits and correct rejections and, in essence, resulted in random lever selection. The lesion did not affect the number of omissions or side bias. Furthermore, the performance of lesioned animals was insensitive to the detrimental effects of distractors. The effects of the lesions do not support an interpretation in terms of sustained attention. Rather, the pattern of the lesioned animals' performance is speculated to reveal a fundamental disruption of decisional processes, reminiscent of the executive dysfunctions observed in patients with damage to ventromedial prefrontal areas or with schizophrenia.

Animals↗
PubMed1985

An electromyographic analysis of electrically-evoked prey-catching behavior by means of stimuli applied to the optic tectum in the Japanese toad.

As a step toward elucidating the tectal-controlling functions for generating the prey-catching motor pattern, electrically-evoked "snapping" (the final consummatory phase of the prey-catching sequence) by means of stimuli applied to the optic tectum was analyzed using electromyographic methods in freely-moving Japanese toads. Electromyographic activities were recorded from the following 7 muscles in the head region (the presumed "snapping"-related muscles): M. depressor mandibulae, M. temporalis, M. sternohyoideus, M. geniohyoideus, M. genioglossus, M. hyoglossus, and M. submentalis. It was found that the characteristic activities evoked in these muscles were associated with jaw/tongue movements during the electrically-evoked "snapping". All of these muscles, except for sternohyoideus and geniohyoideus muscles, were activated in an all-or-nothing manner which corresponded to the elicitation of the electrically-evoked "snapping". It was suggested that such an all-or-nothing character may reflect an all-or-nothing property of the neuronal circuits for generating the prey-catching motor-pattern.

Animals↗
PubMed1992

Food granules elicit heavy drinking in polydipsic rats independently of meal duration.

Excessive drinking, in rats made polydipsic on intermittent delivery of food pellets, is inversely related to the time the rat spends with its head in the feeder, early in the interfood interval. In a sensitization model, this explains why food textures that induce more oral activity, e.g., powder, do not elicit drinking. This hypothesis was examined by coding the behavior of polydipsic rats and varying the duration of the meal delivered in each interval, while holding texture constant. Polydipsic rats were presented with pellets, food granules, or food powder. The food granules were dispensed over periods lasting 1, 14, 21, and 28 s. All food deliveries were of the same mass. The food was delivered periodically at 60-s intervals in each condition. The 14 rats in the experiment served as their own controls by experiencing every condition. The food granule conditions induced the expected increases in feeding early in the interval. However, instead of progressively reducing drinking, the excessive drinking simply occurred later in the interval. By contrast, the powder condition resulted in the immediate elimination of polydipsia. The results suggest that food texture elicits excessive drinking independently of temporal factors and that elicitation of the sensitized drinking response must depend on other factors.

Animals↗
PubMed2000

Loss of the innate cortical engram for action patterns used in skilled reaching and the development of behavioral compensation following motor cortex lesions in the rat.

Damage to the motor cortex of the rat (Rattus norvegicus) impairs skilled movements used in reaching for food with the contralateral forepaw. Nevertheless, there is substantial recovery in success over a two-week postsurgical period. The profile of behavioral recovery is believed to reflect the eventual normalization of behavior, but this idea has not been explicitly examined. The present experiments examined postsurgical reaching success and reaching movements as a function of (1) lesion type, (2) lesion size, (3) lesion location, (4) depletion of forebrain noradrenaline, and (4) presurgical and postsurgical experience. The results show that at least two separate processes contribute to recovery in postsurgical performance. The early postsurgical period was characterized by extreme difficulties in making reaching movements. The experiments suggest that this initial impairment was due to the loss of the innate cortical engram that supports the action patterns used for skilled movements. Subsequent recovery in reaching success was not due to the reacquisition of normal movements, but was due rather to the use of compensatory movements. The results are discussed in relation to the idea that true recovery from motor cortex injury will require that damaged neurons and their connections be rescued or replaced.

Animals↗
PubMed1992

Perceptual bisection in rats: the effects of physostigmine, scopolamine and pirenzepine.

The effects of cholinergic drugs on three different perceptual bisection tasks were studied in rats. Physostigmine (0.056-0.56 mg/kg), a reversible anticholinesterase, produced dose-dependent decrements in discriminability (A'), but did not affect the bisection point (BP) in visual duration, auditory duration, and auditory intensity bisection tasks. This finding is consistent with results previously obtained in an auditory duration bisection task with an irreversible anticholinesterase, diisopropyl phosphofluoridate. Scopolamine (0.075-0.422 mg/kg), a muscarinic cholinergic-receptor antagonist, produced dose-dependent decrements in both A' and BP in visual and auditory duration bisection tasks. The behavioral antagonism between physostigmine (0.56 mg/kg) and scopolamine (0.075-0.237 mg/kg) was studied in the visual and auditory duration bisection tasks. The BP was not affected by physostigmine alone or in combination with scopolamine, except at the largest dose of scopolamine, which produced a reliable decrement in the BP. A', however, was equally decreased by physostigmine alone and all combinations of physostigmine and scopolamine. Pirenzepine (1, 3 and 10 mg/kg), a selective high-affinity M1 muscarinic antagonist, had no effect on A' or the BP in the duration bisection tasks, suggesting changes in perception produced by muscarinic antagonists do not involve the M1 receptor subtype. The similar drug effects in different sensory modalities (visual and auditory) and perceptual systems (subjective duration and loudness) suggest that cholinergic drugs may affect perceptual mechanisms responsible for sensory coding, such as the output of a neural generator.

Animals↗
PubMed1989

Ingestion of environmentally contaminated Lake Ontario salmon by laboratory rats increases avoidance of unpredictable aversive nonreward and mild electric shock.

To determine what behavioral changes are caused by consumption of Lake Ontario salmon, a 30% diet of Lake Ontario or control Pacific Ocean salmon was fed to rats for 20 days. In Experiments 1 and 2 (preference-for-predictability E-maze test), rats fed Lake Ontario salmon developed a preference for predictable food rewards more quickly than did the control rats. In Experiments 3 (passive avoidance) and 4 (conditioned suppression), rats fed Lake Ontario salmon suppressed responding to food far more after the introduction of mild electric shocks than did control rats. All results supported the hypothesis that ingestion of Lake Ontario salmon, contaminated with polychlorinated biphenyls, mercury, lead, etc., increases the reactivity of rats to aversive events. The results were successfully simulated by DMOD, a mathematical model of learning, using the assumption that rats fed Lake Ontario salmon find unpredictable nonreward and mild shock more aversive.

Animals↗
PubMed2005

Host-seeking strategies of mosquito disease vectors.

Disease transmission by arthropods normally requires at least 2 host contacts. During the first, a pathogen (nematode, protozoan, or virus) is acquired along with the blood from an infected vertebrate host. The pathogen penetrates the vector's midgut and infects a variety of tissues, where replication may occur during an extrinsic incubation period lasting 3-30, days depending on vector and parasite physiology and ambient temperature. Following salivary-gland infection, the pathogen is usually transmitted to additional susceptible vertebrate hosts during future probing or blood feeding. The host-seeking strategies used by arthropod vectors can, in part, affect the efficiency of disease transmission. Vector abundance, seasonal distribution, habitat and host preference, and susceptibility to infection are all important components of disease-transmission cycles. Examples of 3 mosquito vectors of human disease are presented here to highlight the diversity of host seeking and to show how specific behaviors may influence disease-transmission cycles. In the African tropics, Anopheles gambiae s.s. is an efficient vector of human malaria due to its remarkably focused preference for human blood. Aedes aegypti is the main vector of dengue viruses in the New and Old World tropics and subtropics. This mosquito has evolved a domestic lifestyle and shares human habitations throughout much of its range. It prospers in settings where humans are its main source of blood. In south Florida, Culex nigripalpus is the major vector of St. Louis encephalitis (SLE) and West Nile (WN) viruses. This mosquito is opportunistic and blood feeds on virtually any available vertebrate host. It serves as an arboviral vector, in part, due to its ability to produce large populations in a short period of time. These 3 host-seeking and blood-feeding strategies make the specialist, as well as the opportunist, equally dangerous disease vectors.

Aedes↗
PubMed1995

Pyrogens specifically disrupt the acquisition of a task involving cognitive processing in the rat.

In addition to changes in body temperature and other metabolic and physiological responses corresponding to immune activation, pyrogens can induce profound behavioral changes referred to collectively as sickness behavior. One feature of sickness behavior, sometimes reported in clinical settings, but rarely exposed to experimental analysis, is depressed cognitive functioning. The present series of five experiments sought to demonstrate the existence of specific cognitive deficits in rats, independently of any confounding performance effects of pyrogen injections. The behavioral task used, called autoshaping, consisted of presenting hungry Wistar rats with a stimulus (introduction of a retractable lever) that predicted food delivery. Control rats quickly learned to press the lever, although this response does not influence the probability of food delivery. When pyrogens (250 micrograms/kg lipopolysaccharide, 4 micrograms/rat interleukin-1 beta, or 300 mg/rat yeast) were injected to rats during acquisition of this task, they severely disrupted acquisition while the pyrogen was active. The same treatments were, however, without effect on performance when injected later, when performance had stabilized. It is argued that these results demonstrate specific, performance-independent effects of pyrogens on the cognitive processes needed for the acquisition of this task. The results are discussed in terms of the relationship between these effects and the cytokines induced in the brain by pyrogens, and in terms of the exact nature of the cognitive process likely to be affected.

Animals↗
PubMed1992

Influence of anterior subdiaphragmatic vagotomy and TPN on rat feeding behavior.

Total parenteral nutrition (TPN) inhibits food intake and feeding behavior. Whether caloric sensory function of the liver contributes to this food intake and feeding behavior regulation via vagal-afferent innervation was tested after performing anterior hepatic vagotomy or sham operation in rats infused with a TPN solution providing 100% of daily energy needs, given continuously for 4 days. Food intake, meal number, size, duration, meal and intermeal sniffs, and eating activity were measured using an automated computerized rat eater meter (ACREM). TPN infusion resulted in a significant decrease of food intake and feeding indexes in both groups. The vagotomized rats showed a significantly higher food consumption, achieved by greater meal frequency, larger meal size, and longer meal duration. Thus, vagotomized rats consumed more than their controls by eating larger meals more often and of longer duration. Data suggest that anterior hepatic vagotomy interrupts hepatic caloric sensory feedback loop, diminishing inhibitory vagal effects on food intake with TPN, leading to an overall increase in food intake.

Afferent Pathways↗
PubMed1987

Effects of neuroleptic drugs, clonidine and lithium on the expression of conditioned behavioral excitation in rats.

Rats with a history of daily (21 days) amphetamine (2.5 mg/kg) treatment showed enhanced activity when under placebo in their amphetamine-associated environment. We found that this conditioned effect was reduced by haloperidol (0.06; 0.125; 0.25 mg/kg), pimozide (0.25; 0.5 mg/kg) and sulpiride (8; 16; 32 mg/kg) but only at doses similar to or, in the case of pimozide, higher than those required to antagonize the unconditioned stimulant effects of amphetamine (2.5 mg/kg). Conversely, we observed that clonidine (7; 15; 30; 60 micrograms/kg) or lithium regimen (between days 15 and 21) leading to lithium plasma levels of 1.3 +/- 0.1 mEq/l, abolished amphetamine-conditioned hyperactivity but did not affect the unconditioned stimulation of amphetamine or locomotor activity in control rats. Moreover, we found that hyperactivity induced by the daily anticipation of food delivery shared identical pharmacological sensitivity with the behavioural excitation produced by a conditioning history with amphetamine. In light of the antimanic properties of lithium and clonidine and the ability of this latter drug to reduce noradrenergic transmission, our findings raise the possibility that incentive activity may model noradrenergic-dependent aspects of mania.

Animals↗