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 739 records · Page 41Linked to original sources

Role of the lipoxygenase/lyase pathway of host-food plants in the host searching behavior of two parasitoid species, Cotesia glomerata and Cotesia plutellae.

To elucidate the role of the plant lipoxygenase (LOX)/lyase pathway for host search behavior of two parasitic wasps attacking herbivorous larvae, an Arabidopsis mutant (all84) was isolated with a mutation somewhere in the LOX/lyase pathway. Detached leaves of the mutant were shown to release less (Z)-3-hexenal, a first green leaf volatile (GLV) product of the LOX/lyase pathway. The braconid larval parasitoids studied, Cotesia glomerata and Cotesia plutella, differ in their ability to discriminate among plant volatiles induced by feeding of lepidopteran hosts and nonhosts: C. plutella only responds to plant volatiles induced by hosts (Plutella larvae), whereas the response by the more generalist C. glomerata is not host specific. The Arabidopsis mutant all84 infested by Pieris larvae was less attractive to C. glomerata than Arabidopsis wild type (wt) infested by the host larvae. C. glomerata was attracted by two of the GLV biosynthesized through the LOX/lyase pathway, (E)-2-hexenal and (Z)-3-hexenyl acetate. However, attraction of C. plutellae to volatiles from Plutella-infested all84 plants did not differ from attraction to host-infested wt Arabidopsis. Both wasp species were arrested to the respective host-infested edge of the wt leaf by showing characteristic antennal searching behavior on the edge. In C. glomerata, the duration of this searching behavior at the infested leaf edge was significantly shorter on all84 plants than on wt plants. By contrast, the duration of the searching behavior of C. plutellae on the host-infested leaf edge of all84 was not significantly different from that on the wt leaf. These data suggest that the LOX/lyase pathway is directly involved in the production of attractants and arrestants important for host search behavior of the more generalist C. glomerata, but not for the specialist C. plutellae.

Animals↗

Nifedipine blocks retention of a visual discrimination task in chicks.

Reports that the dihydropyridine Ca2+ channel antagonists may facilitate memory led to the present study of the behavioral effects of nifedipine. Ninety-two 4-day-old male chicks received 0, 100 nM, 100 microM, or 10 mM nifedipine. Drugs were administered in volumes of 2 microliters into the fourth cerebral ventricle 5 min before training on a visual discrimination task. Nifedipine did not produce any detectable changes in behavior during acquisition trials. Retention, however, was impaired 24 h after training in the 100 nM and 100 microM nifedipine-treated chicks, which made significantly more errors than controls. Nifedipine did not affect the amount of time required to complete the task. No effects on body weight gain were detected, suggesting that the memory impairment was not due to a change in feeding behavior. These data are discussed in terms of the role of calcium-dependent processes in memory.

Animals↗

Somatosensory cell response to an auditory cue in a haptic memory task.

Neurons in the monkey's anterior parietal cortex (Brodmann's areas 3a, 3b, 1, and 2) have been reported to retain information from a visual cue that has been associated with a tactile stimulus in a haptic memory task. This cross-modal transfer indicates that neurons in somatosensory cortex can respond to non-tactile stimuli if they are associated with tactile information needed for performance of the task. We hypothesized that neurons in somatosensory cortex would be activated by other non-tactile stimuli signaling the haptic movements--of arm and hand--that the task required. We found such cells in anterior parietal areas. They reacted with short-latency activity changes to an auditory signal (a click) that prompted those movements. Further, some of those cells changed their discharge in temporal correlation with the movements themselves, with the touch of the test objects, and with the short-term memory of those objects for subsequent tactile discrimination. These findings suggest that cells in the somatosensory cortex participate in the behavioral integration of auditory stimuli with other sensory stimuli and with motor acts that are associated with those stimuli.

Animals↗

Experience-dependent changes in extracellular spike amplitude may reflect regulation of dendritic action potential back-propagation in rat hippocampal pyramidal cells.

Activity-dependent attenuations in extracellular spike amplitude have been shown to correlate with a decrease in the effectiveness with which somatic action potentials back-propagate into the dendritic arbor of hippocampal pyramidal cells. In this paper we demonstrate that activity-dependent attenuations in amplitude occur during behavior and that the amount of attenuation is reduced with an animal's experience in an environment. The observed reductions are caused by an animal's experience within a specific environmental context, are dependent on functional NMDA receptors, and are accompanied by an increase in the effective coupling of pyramidal cells and interneurons. These results provide an important step in linking together in vivo studies with in vitro data and suggest that mechanisms of plasticity engaged during behavior may be sufficient to alter the biophysical and integrative properties of hippocampal pyramidal cells.

Action Potentials↗

A population of pedal-buccal projection neurons associated with appetitive components of Aplysia feeding behavior.

Backfills of the cerebral-buccal connective (CBC) of Aplysia californica revealed a cluster of five to seven pedal-buccal projection neurons in the anterolateral quadrant of the ventral surface of each pedal ganglion. Intra- and extracellular recordings showed that the pedal-buccal projection neurons shared common electrophysiological properties and synaptic inputs. However, they exhibited considerable heterogeneity with respect to their projection patterns. All pedal-buccal projection neurons that were tested received a slow excitatory postsynaptic potential from the ipsi- and contralateral cerebral-pedal regulator (C-PR) neuron, a cell that is thought to play a key role in the generation of a food-induced arousal state. Tests were conducted to identify potential synaptic follower neurons of the pedal-buccal projection neurons in the cerebral and buccal ganglia, but none were detected. Finally, nerve recordings revealed projections from the pedal-buccal projection neurons in the nerves associated with the buccal ganglion. In tests designed to determine the functional properties of these peripheral projections, no evidence was obtained supporting a mechanosensory or proprioceptive role and no movements were observed when they were fired. It is proposed that peripheral elements utilized in consummatory phases of Aplysia feeding may be directly influenced by a neuronal pathway that is activated during the food-induced arousal state.

Animals↗

Ca2+/calmodulin system: participation on rat sexual hypothalamic differentiation.

Modifications of male rat hypothalamic sexual differentiation after neonatal administration of drugs that participate on the Ca2+/calmodulin system (haloperidol, trifluoperazine, penfluridol, pimozide, and verapamil) were studied. Pups treated 72 h after birth were behaviorally tested on day 120 of extrauterine life. Five tests for homotypical behavior were conducted. Afterwards animals were castrated and tested twice for heterotypical (female) behavior under replacement hormonal therapy. Fifty percent (80% in the case of pimozide) of all treated males showed lordotic behavior compared with none of the controls. Haloperidol (39%, lordosis quotient) and pimozide (40%, lordosis quotient) were more active than the others. Results obtained with verapamil were not statistically different from the controls. Pimozide was the most active agent influencing the appetitive masculine behavior (mount latency, intromission latency, and postejaculatory interval). Verapamil was more efficient than the rest of the drugs on the consummatory behavior (mount latency, intromission frequency, interintromission interval, and ejaculatory latency). Our results support the participation of the Ca2+/calmodulin system in hypothalamic sexual differentiation and in the differential modulation of the masculine and feminine behavioral patterns.

Animals↗

Cuttlefish (Sepia officinalis: Cephalopoda) hunting behavior and associative learning.

Because most learning studies in cephalopods have been performed on octopods, it remains unclear whether such abilities are specific to octopus, or whether they correlate with having a larger and more centrally organized brain. To investigate associative learning in a different cephalopod, six sexually mature cuttlefish (Sepia officinalis) participated in a counterbalanced, within-subjects, appetitive, classical conditioning procedure. Two plastic spheres (conditioned stimuli, CSs), differing in brightness, were presented sequentially. Presentation of the CS+ was followed 5 s later by a live feeder fish (unconditioned stimulus, US). Cuttlefish began to attack the CS+ with the same type of food-acquisition seizures used to capture the feeder fish. After seven blocks of training (42 presentations of each CS) the difference in seizure probability between CS+ and CS- trials more than doubled; and was found to be significantly higher in late versus early blocks. These results indicate that cuttlefish exhibit autoshaping under some conditions. The possible ecological significance of this type of learning is briefly discussed.

Animals↗

"Central arousal" and sexual responsiveness in the snail, Helix aspersa.

In molluscs, a "central arousal" system is thought to positively modulate both an animal's level of activity and its behavioral responsiveness. This hypothesis is examined in Helix aspersa by testing the relationships between activity, feeding, and sexual behavior. Activity, feeding, and mating exhibit parallel daily rhythms. Snails are most active, and eat and mate most frequently, during scotophase and the first 3 h of photophase. Handling and injections of serotonin (5 x 10(-7) m/kg body wt) increase general activity. Inducing activity during late photophase increases food consumption, but it does not induce sexual activity. Moreover, serotonin and handling have no effect on sexual arousal; treated snails show no increase in genital eversion stage and require the same length of courtship as controls. If snails are sexually deprived, increasing activity in late photophase does increase copulation frequency, but snails do not copulate more frequently than do unhandled snails tested during early photophase. These results suggest that while manipulations thought to increase central arousal do increase activity and responsiveness to food stimuli, they do not directly affect sexual proclivity or sexual arousal. Moreover, the relationship between feeding and sexual behavior differs between Helix and Aplysia. This difference between the two species may be related to the differences in their reproductive strategies.

Animals↗

The metabotropic glutamate 2/3 receptor agonist LY404039 reduces alcohol-seeking but not alcohol self-administration in alcohol-preferring (P) rats.

Metabotropic glutamate (mGlu) receptors have been shown to mediate a number of behaviors including emotionality and responsivity to stress as demonstrated by efficacy in preclinical and clinical studies. The objective of this study was to assess the effects of the mGlu2/3 receptor agonist LY404039 (LY) on operant ethanol (EtOH) self-administration during alcohol seeking (pavlovian spontaneous recovery, PSR), alcohol relapse (alcohol deprivation effect, ADE), and maintenance responding for alcohol. Adult alcohol-preferring (P) rats were trained in 2-lever operant chambers to self-administer 15% EtOH (v/v) and water on a concurrent fixed-ratio 5-fixed-ratio 1 (FR5-FR1) schedule of reinforcement in daily 1h sessions. After at least 10 weeks of daily 1 h sessions, rats underwent seven extinction sessions, followed by 2 weeks of no manipulation, and then rats were tested for the expression of an EtOH PSR for four sessions. Rats were then given a week in their home cage before being returned to the operant chambers with access to EtOH and water (alcohol relapse). Finally, the effects of LY upon maintenance EtOH and water responding were assessed once stable responding was reestablished. The mGlu2/3 receptor agonist LY404039 reduced responding on the EtOH in the PSR test. LY also reduced the expression of an alcohol deprivation effect (ADE) during relapse, but did not reduce EtOH responding under maintenance conditions. The results of this study demonstrate that activating mGlu2/3 receptors inhibits the expression of alcohol seeking and relapse behavior without altering alcohol self-administration behavior.

Alcohol Drinking↗

Hygienic behavior of the honey bee (Apis mellifera) is independent of sucrose responsiveness and foraging ontogeny.

Hygienic behavior in honey bees is a behavioral mechanism of disease resistance. Bees bred for hygienic behavior exhibit an increased olfactory sensitivity to odors of diseased brood, which is most likely differentially enhanced in the hygienic line by the modulatory effects of octopamine (OA), a noradrenaline-like neuromodulator. Here, we addressed whether the hygienic behavioral state is linked to other behavioral activities known to be modulated by OA. We specifically asked if, during learning trials, bees from hygienic colonies discriminate better between odors of diseased and healthy brood because of differences in sucrose (reward) response thresholds. This determination had to be tested because sucrose response thresholds are susceptible to OA modulation and may have influenced the honey bee's association of the conditioned stimulus (odor) with the unconditioned stimulus (i.e., the sucrose reward). Because the onset of first foraging is also modulated by OA, we also examined whether bees from hygienic colonies differentially forage at an earlier age compared to bees from non-hygienic colonies. Our study revealed that 1-day- and 15- to 20-day-old bees from the hygienic line do not have lower sucrose response thresholds compared to bees from the non-hygienic lines. In addition, hygienic bees did not forage at an earlier age or forage preferentially for pollen as compared to non-hygienic bees. These results support the idea that OA does not function in honey bees simply to enhance the detection of all chemical cues non-selectively or control related behaviors regardless of their environmental milieu. Our results indicate that the behavioral profile of the hygienic bee is sculpted by multiple factors including genetic, neural, social and environmental systems.

Animals↗

Mesotelencephalic dopamine system and reproductive behavior in the female rat: effects of ventral tegmental 6-hydroxydopamine lesions on maternal and sexual responsiveness.

The effects of lesions to the mesolimbic dopamine system on maternal and sexual behaviors in the female rat was assessed. Rat dams that were given ventral tegmental area microinfusions of 6-hydroxydopamine (6-OHDA) during lactation showed a persistent deficit in pup retrieval but were not impaired with respect to nursing, nest building, or maternal aggression. In addition, 6-OHDA-lesioned females failed to respond to amphetamine by showing locomotor hyperactivity. Administration of the dopamine blocker raclopride to neurologically intact dams also inhibited pup retrieval but had no effect on nursing. Females given 6-OHDA during pregnancy appeared completely unresponsive to pups, whereas no maternal deficits were seen in females that received 6-OHDA 8 weeks before parturition. Proceptive (hopping and darting) and receptive (lordosis) components of sexual behavior, assessed after ovariectomy and exogenous steroid hormone treatment, were not affected by mesolimbic 6-OHDA lesions.

Animals↗

Cognitive functions and aging in the dog: acquisition of nonspatial visual tasks.

Old, middle-aged, and young dogs were compared on discrimination and reversal learning and on acquisition of a delayed-nonmatching-to-sample (DNMS) test of recognition memory. DNMS acquisition was acquired more rapidly by young dogs. Reversal deficits were found between aged mixed-breed dogs and young beagles, but not between old and young beagles. Aged beagles also showed unexpected deficits in reward approach and object approach learning. Aged mixed-breed dogs did not show deficits in reward approach and object approach learning, but they learned the discrimination task more slowly than the age-matched beagles. A detailed analysis of response patterns indicated that once present, the development of side preferences contributed to deficits of old dogs in discrimination learning. In the discrimination reversal, old dogs were more persistent in responding to the previously rewarded stimulus object. Findings suggest that the dog, like other species, shows age-dependent deterioration in cognitive function, the extent of deterioration is a function of both task and previous experience, and at least part of the deterioration is a result of increased behavioral rigidity. Results also indicate that it is important to control for breed differences and previous experience.

Aging↗

Role of the dorsomedial striatum in behavioral flexibility for response and visual cue discrimination learning.

These experiments examined the effects of dorsomedial striatal inactivation on the acquisition of a response and visual cue discrimination task, as well as a shift from a response to a visual cue discrimination, and vice versa. In Experiment 1, rats were tested on the response discrimination task followed by the visual cue discrimination task. In Experiment 2, the testing order was reversed. Infusions of 2% tetracaine did not impair acquisition of the response or visual cue discrimination but impaired performance when shifting from a response to a visual cue discrimination, and vice versa. Analysis of the errors revealed that the deficit was not due to perseveration of the previously learned strategy, but to an inability to maintain the new strategy. These results contrast with findings indicating that prelimbic inactivation impairs behavioral flexibility due to perseveration of a previously learned strategy. Thus, specific circuits in the prefrontal cortex and striatum may interact to enable behavioral flexibility, but each region may contribute to distinct processes that facilitate strategy switching.

Animals↗

Genetic determinants of susceptibility to the rewarding and other behavioral actions of cocaine.

The role of genotype as a determinant of biologically based inter-individual differences in vulnerability to substance abuse has received little systematic investigation except in the case of alcohol. This report describes the use of an animal model, the inbred mouse, to identify and to characterize variants with inherently altered susceptibilities to the rewarding and other behavioral actions of cocaine. Among a battery of nine inbred strains chosen solely for their genetic diversity, genetic polymorphisms commonly occurred which altered the potency and/or efficacy of cocaine to induce conditioned place preference, oral self-administration, motor activity activation, seizures and lethality. These changes in cocaine sensitivity generally were of a behavior-specific and pharmacodynamic nature. One strain, DBA/2J, found to be markedly hyporesponsive to the rewarding action of cocaine, also was hyporesponsive to the rewarding effects of amphetamine, etonitazene, phencyclidine, caffeine and procaine. We speculate that this strain has an inherent generalized appetitive defect. The frequent occurrence and large magnitude of inherent phenotypic changes in cocaine responsiveness which we have identified among inbred mouse strains now permits an analytical genetic study of processes underlying cocaine-mediated reinforcement.

Animals↗

Differential effects of omission contingencies on various components of Pavlovian appetitive conditioned responding in rats.

Five experiments with rat subjects investigated the effects of omission and partial reinforcement contingencies on five individual behaviors evoked by visual and auditory conditioned stimuli paired with a food unconditioned stimulus. The effects of omission depended on the behavior on which that contingency was placed: One behavior was eliminated, one was unaffected, and three were reduced relative to the performance of yoked controls. Partial reinforcement resulted in lower frequencies of three behaviors and higher frequencies of two behaviors, compared with performance under consistent reinforcement. A partial reinforcement extinction effect was noted with one behavior but not with the others. These results are related to the possible role of instrumental conditioning contingencies in generating conditioned behavior in this appetitive conditioning preparation and to the independence of individual components of a complex conditioned response.

Animals↗

Differential involvement of NMDA, AMPA/kainate, and dopamine receptors in the nucleus accumbens core in the acquisition and performance of pavlovian approach behavior.

Stimuli paired with primary rewards can acquire emotional valence and the ability to elicit automatic, Pavlovian approach responses that have been shown to be mediated by the nucleus accumbens. The present experiment investigated the effects of infusions of glutamatergic or dopaminergic receptor antagonists into the core of the nucleus accumbens on the acquisition and performance of Pavlovian discriminated approach to an appetitive conditioned stimulus. Rats were trained on an autoshaping task in which a conditioned stimulus (CS+; a lever) was inserted into the operant chamber for 10 sec, after which a food pellet was delivered. Presentation of another lever (CS-) was never followed by food. Subjects developed a conditioned response of approaching and contacting the CS+ selectively, although food delivery was not in any way contingent on the animals' response. A triple dissociation in the effects of AP-5, LY293558 [(3SR, 4aRS, 6RS, 8aRS)-6-[2-(iH-tetrazol-5-yl)ethyl]-1,2,3,4,4a,5,6,7,8,8a-decahydroiso-quinoline-3-carboxylic acid], and alpha-flupenthixol infused into the nucleus accumbens core on the acquisition and performance of this conditioned response was observed. The AMPA/kainate receptor antagonist LY293558 disrupted discriminated approach performance but not acquisition, as evidenced by increased approaches to the CS-. In contrast, the NMDA receptor antagonist AP-5 impaired only the acquisition, but not performance, of autoshaping whereas the dopamine D1/D2 receptor antagonist alpha-flupenthixol decreased approaches to the CS+ during both acquisition and performance. The data are discussed with reference to dissociable interactions of these receptor types with limbic cortical and dopaminergic afferents to the nucleus accumbens core during the acquisition and expression of Pavlovian conditioned approach.

2-Amino-5-phosphonovalerate↗

The role of cytokines in the behavioral responses to endotoxin and influenza virus infection in mice: effects of acute and chronic administration of the interleukin-1-receptor antagonist (IL-1ra).

Following infection with influenza virus, animals display decreased locomotor activity and feeding behavior and loss of body weight. It has been suggested that these effects may be mediated by cytokines, such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha), induced by the infection. To assess the potential role of IL-1, we tested the ability of a naturally occurring IL-1-receptor antagonist (IL-1ra) to antagonize the changes in feeding behavior induced by IL-1, endotoxin (lipopolysaccharide, LPS), and infection with influenza virus. Feeding behavior was assessed by measuring the daily intake of food pellets and sweetened milk in a 30-min period. Acute injection of IL-1 beta decreased milk intake, but mouse IL-6 and mouse TNF-alpha did not. However, TNF-alpha decreased food pellet intake slightly, especially when it was injected at the beginning of the dark phase. The reductions in milk intake induced by mouse IL-1 beta were largely prevented by IL-1ra pretreatment (100 micrograms/mouse i.p.). The LPS-induced reductions in milk intake were attenuated, but not blocked, by IL-1ra treatment (300 micrograms/mouse). LPS still induced significant decrements in the presence of the antagonist. In influenza virus-infected mice, IL-1ra was administered either by repeated subcutaneous (s.c.) injections, or by continuous s.c. infusion from osmotic minipumps. These IL-1ra treatments produced small, but statistically significant, attenuations of the depression in milk and food pellet intake in the virus-infected mice. In several experiments, IL-1ra treatment increased the survival of influenza virus-infected mice. Thus the attenuation of the hypophagia may have been caused by this IL-1ra-induced increase in survival. The results suggest that IL-1 contributes to sickness behavior induced by LPS and influenza virus infection, but it is not the only factor involved.

Animals↗