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 1,567 records · Page 87Linked to original sources
PubMed1994

Bilateral destruction of the ventrolateral orbital cortex produces allocentric but not egocentric spatial deficits in rats.

Previous studies have implicated the ventrolateral orbital cortex (VLO) in spatial attention and orientation. Unilateral destruction of the VLO has been found to produce severe multimodal neglect to unilateral stimulation which is qualitatively quite similar to that found following unilateral destruction of either the medial agranular or posterior parietal cortices. A series of anatomical studies have shown that the VLO is reciprocally interconnected with both the medial agranular cortex and the posterior parietal cortex, which are involved in egocentric and allocentric spatial processing respectively. However, the role of the VLO in either egocentric or allocentric spatial processing has never been directly examined. The present study directly examined the role of the VLO in spatial learning by examining the effects of bilateral VLO destruction on performance in both egocentric (adjacent-arm maze task) and allocentric (cheeseboard task) spatial tasks. Subjects in either the cheese board task or the adjacent arm maze were given presurgical maze training and then were assigned to one of three surgical groups: a bilateral VLO group, a lesion control group which received bilateral destruction of the laterally adjacent lateral orbital cortex which has a quite different pattern of connectivity than the VLO, or a sham operated control group. The results indicated that the VLO operates were significantly impaired in the cheeseboard task (allocentric task) relative to controls, but displayed no deficits in the adjacent-arm maze (egocentric task), a pattern of results similar to those found for the posterior parietal cortex. The results of the present study strongly support the contention that the VLO is a component of the cortical circuitry for spatial processing in rodents.

Animals↗
PubMed1994

The prefrontal cortex and variants of sequential behaviour indications of functional differentiation between subdivisions of the rat's prefrontal cortex.

In two separate experiments we addressed the involvement of the rat's prefrontal cortex in mediation of the sequential ordering of the "components of behaviour". In both experiments the animals were required to operate two different and spatially distant manipulanda sequentially. While in the first experiment a light cue signalled which response would at any moment be appropriate no sensory cues offered procedural guidance during the second experiment. Both experiments focused on postoperative retention performance. In the first experiment we studied the consequences of ablation of the dorsal anteromedial cortex, the total anteromedial cortex and the suprarhinal cortex as compared to a sham operated control group. In the second experiment we compared a sham operated group to a group subjected to ablation of the total anteromedial cortex. While the proficiency of task performance was evaluated on the basis of the number of reinforcements obtained and the percentage of bar presses to be reinforced, additional analysis of behaviour included registration of the individual behavioural components and the sequential orders in which these were observed. The major findings were: (1) lesions within the anteromedial, prefrontal cortex (especially if including the ventral part of this region) are associated with significantly impaired performance of both the presently investigated tasks. (2) The demonstrated association between the anteromedial cortex and the mediation of the sequential arrangement of behavioural components does not seem to be secondary to changes in neither quality nor frequency of any individual behavioural component. (3) In the first experiment--where a cue light signalled which response would at any point in time be adequate--lesions within all parts of the prefrontal cortex (the suprarhinal as well as the anteromedial cortex) were associated with overproduction of errors, which in the behavioural sequence analysis had been characterized as "type B". We tentatively interpret such errors as reflecting a failure to utilize the visual cue offered by the signal lamp. Since lesions within all parts of the prefrontal cortex seem to be associated with "cue utilization" failures while only lesions involving the anteromedial cortex are reflected in impaired sequential arrangement of behavioural components the present studies seem to reflect a certain degree of functional specialization within the prefrontal cortex of the rat.

Animals↗
PubMed1994

Neuronal responses to photographs in the superior temporal sulcus of the rhesus monkey.

The activity of a total of 174 visual neurons in the superior temporal sulcus (mostly area TE) of rhesus monkeys was examined quantitatively using complex visual stimuli. Colored photographs of human faces (n = 411), monkeys (n = 308), and non-face objects (n = 35), as well as computer-generated graphics were presented as visual stimuli during a performance of a visual discrimination task. All neurons responded to a limited number of photographs. We quantified these stimulus-selective responses, using two kinds of selectivity indices. With the first index (SI1), we attempted to estimate how many stimuli produced a significant response. The mean value of SI1 was 0.63. About 31% of neurons had values of SI1 greater than 0.8. With the second index (SI2), we attempted to estimate how many stimuli could be distinguished from the stimulus that elicited the strongest activity. The mean value of the SI2 was 0.71. About 51% of neurons had values of SI2 greater than 0.8. About 66% of neurons had values of either SI1 or SI2 that were greater than 0.8, a value that corresponds to a selectivity of one out of five stimuli. We designated these neurons as stimulus-selective (SS) neurons. Of these SS neurons, 45% showed the best response to human faces. Similarly, 28.8% showed the best response to a photograph of monkeys. 7.5% to food, 8.8% to non-food and 10% to simple graphics, such as, a colored square or a circle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Arpeggio and fractionated digit movements used in prehension by rats.

Although it is well known that rats can use one limb to reach for and retrieve food, the way that the paw and digits are used to grasp the food has not been described. Using results obtained from a high speed videorecording procedure, the present study describes how small and large pieces of food are located by the paw and grasped with the digits in a reaching task. As the rat pronates a paw over food, the tips of digits 5 through 2 are successively placed and spread over the target area in an arpeggio movement. The target area is then palpated by downward movements of the palm. If food is not present, the paw is withdrawn without grasping. If food is contacted, the food is manipulated and grasped by the digits with grasp patterns that depend upon food size. Large food pellets are contacted with the pad of digit 3 and then grasped between digits 3 and 4. Small food pellets are first contacted with pad of digit 4 and are grasped between digits 4 and 5. Digit 5 can be partially flexed medially so that the food is held in a modified power grip between digits 4 and 5. The results show that rats use a whole paw movement to position the digits in an arpeggio fashion and they use fractionated digit movements to grasp food. The results are discussed in relation to the possible comparative and anatomical significance of the movements.

Animals↗
PubMed1994

Effects of intracranial injections of scopolamine on olfactory conditioning retrieval in the honeybee.

The role of the cholinergic system on learning abilities and memory performance has been investigated in the honeybee. The behavioural experiment was the olfactory conditioning of the proboscis extension reflex, elicited by an antennal sucrose stimulation. Intracranial scopolamine (0.5 mg/kg) or saline injections (0.25 microliter) were given at different times before or after a one trial learning session in order to interfere with acquisition of information, storage or recall processes. Neither scopolamine injections, ranging from 20 min to 5 min prior to the acquisition task, nor post-trial drug injections given in the same time-window, impaired the retention performance measured one hour after conditioning. Scopolamine injected 20 min after a learning session induced a time-dependent decrease of information retrieval, as was seen in retention testing performed from 5 min to one hour after injection. Then, the amnestic effect of intracranial scopolamine injection seems to be related to a specific and temporary inhibition of recall processes. We can conclude that, in the present task, muscarinic-like receptors are involved in information retrieval but not in acquisition or consolidation processes.

Animals↗
PubMed1994

Substance P decreases extracellular concentrations of acetylcholine in neostriatum and nucleus accumbens in vivo: possible relevance for the central processing of reward and aversion.

It has been shown that peripherally administered substance P has reinforcing effects and can promote functional recovery after unilateral partial lesion of the nigrostriatal system. Furthermore, peripheral injection of substance P induces an increase in extracellular striatal dopamine. To obtain further information about the central mechanisms of these properties we used the in vivo microdialysis technique to investigate changes in the extracellular concentrations of acetylcholine in neostriatum and nucleus accumbens after intraperitoneal (i.p.) administration of substance P or vehicle in freely moving rats. The i.p. administration of 50 micrograms/kg substance P induced a steady, long-lasting decrease in the extracellular concentrations of acetylcholine in neostriatum, while no changes were observed in the nucleus accumbens. In comparison, substance P in a dose of 250 micrograms/kg i.p. acutely decreased the extracellular levels of acetylcholine in both nuclei. Interestingly, after the administration of vehicle, an acute increase in acetylcholine levels was observed in the nucleus accumbens, but not in the neostriatum. This effect did not occur after the injection of substance P indicating that the neurokinin blocked the increase in acetylcholine levels induced by the vehicle injection. These effects of substance P on striatal acetylcholine are discussed with respect to their relationship with dopamine and endogenous opiates, and with respect to the functional role of substance P, such as in reward, aversion, motor activity, and functional recovery.

Acetylcholine↗
PubMed1994

Differential effects of lesions of the dorsomedial and dorsolateral caudate-putamen on reaction time performance in rats.

In order to investigate the role of the dorsomedial and dorsolateral caudate-putamen (CPu) in movement initiation of rats, we examined the effects of quinolinic acid lesions (30 nmol in 1 microliter) in these striatal subregions in a simple reaction time task. Results show that lesions of the dorsomedial, but not of the dorsolateral CPu increased reaction times. These findings provide further evidence for a functional heterogenity of the CPu and demonstrate an involvement of the dorsomedial CPu in processes related to rapid initiation of responses.

Animals↗
PubMed1996

Unilateral amygdala inactivation after training attenuates memory for reduced reward.

This experiment examined the effects of unilateral inactivation of the amygdalae on memory for reduction in reward magnitude. Male Sprague-Dawley rats with bilateral cannulae in the amygdala were trained to run a straight alley for ten 45-mg food pellets. On Day 10, half the animals were shifted to a 1 pellet food reward and half continued to receive 10 pellets. After the shift, the shifted animals displayed a marked increase in response latencies. Immediately following training on Day 10, the animals received bilateral intra-amygdala infusions (0.5 microliter/side) of phosphate buffer or 2% lidocaine in one amygdala simultaneously with infusion of buffer in the other amygdala. On Day 11, the shifted animals given bilateral buffer infusions displayed an increase in response latencies greater than that of the unshifted groups or the shifted groups given lidocaine unilaterally. On Day 12, the runaway latencies of the Shifted Vehicle group remained significantly higher than those of the Unshifted Vehicle group and the Shifted Unilateral Lidocaine-Right group but were not significantly different from those of the Shifted Unilateral Lidocaine-Left group. Also, the latencies of the Shifted Unilateral Lidocaine-Left group were significantly longer than those of the Shifted Unilateral Lidocaine-Right group. These findings indicate that post-shift inactivation of only one amygdala can attenuate the response to reward reduction. These results are consistent with previous evidence that the right amygdala may be more involved than the left in consolidation of memory storage for aversive experience.

Amygdala↗
PubMed1988

Sham drinking of glucose solutions in rats: some effects of hydration.

Sham-drinking patterns were observed in rats with oesophageal fistulae and gastric cannulae. In rats both food- and water-deprived at test, first-session sham intake was an inverted U-shaped function of glucose concentration (the preference-aversion pattern). Sham intake at low and high extremes rose with repeated exposure, so that the function flattened. When the rats were hydrated by a gastric water preload, sham intake of glucose at low concentrations was much reduced, whereas sham intake at high concentrations was little affected, so that the function became monotonic increasing. This time sham intake rose with repeated testing at high concentrations, but not low ones, so that the function steepenned. At low concentrations, the low sham intakes reflected a rapid termination of the sham-drinking bout. This does not reflect a delayed effect of the gastric water load, for introducing a further delay between load and drinking test did not enhance the effect. Finally, an intragastric load of isotonic NaCl was less effective than water in suppressing sham drinking, just as it is less effective in inhibiting thirst. We conclude: (1) sham drinking is terminated by an accumulation of orosensory feedback; and (2) the taste presented to the mouth, and the animal's hydrational status, jointly determine the amount of such feedback that is necessary to end the ingestive bout.

Animals↗
PubMed1988

Glucose sham drinking in the rat: satiety for the sweet taste without the sweet taste.

In rats sham drinking through oesophageal fistulae, sham intake of a dilute glucose solution (0.25 M) is greatly reduced, but not abolished, by an intragastric water preload. Since no further fluid enters the body, the early cessation of sham drinking must reflect a purely oral control, set by hydrational status. We show that lapping after the water load is abolished if the rat has sham-drunk appreciable quantities before the load is delivered. This is true even if the initial sham drinking is of plain water, with no sweet taste. Therefore, (1) the effect of the preload is to set the total quantity of oral feedback required to end the sham drinking bout; and (2) the necessary oral feedback is provided by the lapping response itself. It does not depend upon gustation.

Animals↗
PubMed1991

Chocolate craving and liking.

Liking and craving for chocolate and related substances were surveyed in a sample of University of Pennsylvania undergraduates (n = 249) and their parents (n = 319). Chocolate was highly liked in all groups, with a stronger liking by females. Chocolate is the most craved food among females, and is craved by almost half of the female sample (in both age groups). Although this craving is related to a sweet craving, it cannot be accounted for as a craving for sweets. About half of the female cravers show a very well defined craving peak for chocolate in the perimenstrual period, beginning from a few days before the onset of menses and extending into the first few days of menses. There is not a significant relation in chocolate craving or liking between parents and their children. The current motivation for chocolate preference seems to be primarily, if not entirely, sensory. Liking for chocolate correlates significantly with liking for sweets and white chocolate. The liking for the sensory properties could originate in innate or acquired liking based on the sweetness, texture and aroma of chocolate, or it could be based in part on interactions between the postingestional effects of chocolate and a person's state (e.g., mood, hormone levels). Based on correlational data, we find little evidence for a relation between addiction to chocolate or the pharmacological (e.g., xanthine-based) effects of chocolate and the liking for chocolate.

Adolescent↗
PubMedDate not supplied

Effects of anti-CCK-8 antiserum on acquisition and retrieval by mice in an appetitive task.

Endogenous cholecystokinin (CCK) was blocked in the posterior cingulate cortex of BALB/c mice using a local injection of anti-CCK-8 antiserum, and memory effects were tested using Go-No Go visual discrimination conditioning. Injection of 0.4 microliter of anti-CCK-8 antiserum diluted to 1:10, 10-15 min before each session, produced substantial learning impairment on the discrimination task. But when injections were stopped, animals began to learn the task normally, showing that the anti-CCK antiserum effect was reversible. When the antiserum was administered at the same dose before a single test session 14 days after the end of the initial training, the retrieval process was also disturbed. These results show that cingulate cholecystokinin is essential for memory processes and suggest that cholecystokinin octapeptide may be a neuromodulator of the thalamo-cingulate pathway of Papez's circuit, which is involved in memory processes.

Animals↗
PubMedDate not supplied

Dynorphin(1-13) impairs memory formation for aversive and appetitive learning in chicks.

The opioid peptide dynorphin(1-13) impairs memory formation in chicks (5). We examined whether this occurs for both aversively and appetitively motivated learning. Four-day-old chicks were injected with dynorphin(1-13) into the intermediate medial hyperstriatum ventrale and trained on either a peck avoidance (PA) or an appetitive discrimination (AD) task; 2-day-old chicks were trained on PA. In 2-day-old chicks, dynorphin was amnestic for PA at 0.01, 0.03, or 0.1 mM. In 4-day-old chicks, dynorphin impaired memory formation for PA at 0.1 mM, and for AD training at 0.03 mM. Thus, similar doses of dynorphin impair memory formation for both appetitive and aversive conditioning.

Animals↗
PubMed1992

Dopamine functions in appetitive and defensive behaviours.

The data reviewed here are compatible with the hypothesis that telencephalic dopamine activity is elicited by motivationally significant stimuli which in turn creates a neural state in which animals are more prepared to respond to significant stimuli in the environment. This analysis may be viewed as extensions of both the sensorimotor hypothesis, which depicts dopamine as potentiating the ability of stimuli to elicit responses (Clody and Carlton, 1980; Marshall et al., 1974; White, 1986) and of the incentive motivational hypothesis, which emphasizes the importance of dopamine in responding to stimuli that serve as signals of biologically significant events (Blackburn et al., 1989a; Crow, 1973; Mogenson and Phillips, 1976). In addition, we have sought to emphasize that not all responses are equally dependent upon the integrity of forebrain dopamine activity. Some responses, such as ingestion of standard foods by hungry animals, copulation, and escape, are relatively impervious to dopamine disruption. Further, once other behaviours, such as avoidance or appetitive operant responses, have been acquired, they can be maintained at an initially high rate despite perturbation of dopamine systems, although performance deteriorates with repeated testing. This analysis has emerged from the joint consideration of how both appetitive and defensive behaviours are influenced by dopamine antagonists, along with an examination of dopamine release during sequences of behaviour. The data reviewed suggest that dopamine is involved in fundamental psychological processes through which environmental stimuli come to exert control over certain aspects of behaviour. In the future, as knowledge in this field advances, there will have to be an integration of the literature on dopamine and motivation with the literature on dopamine and motor systems. We expect that dopamine release will be seen as a mechanism by which important environmental cues, of innate or learned significance, lead to a general enhancement of motor skeletal responses directed towards distal cues. We conclude with a caveat: Caution must be exercised when attempting to infer a general role of any neurotransmitter in motivated behaviour based on the study of a limited number of motivational systems. Although neurotransmitter pathways may figure prominently in the control of certain behaviours, it is incorrect to think of neurotransmitters as having a single role in behaviour. However, when comparative analyses reveal a common thread among different motivational systems, as is becoming apparent for the general role of mesotelencephalic dopamine pathways in behaviour, then the goal of generating coherent and comprehensive theory concerning a neurotransmitter's function in behaviour will begin to be realised.(ABSTRACT TRUNCATED AT 400 WORDS)

Aggression↗
PubMed1980

Emotional correlates of selection for avoidance learning in rats.

The Roman high-avoidance (RHA) and low-avoidance (RLA) strains of rats were tested and compared with Maudsley reactive (MR) and non-reactive (MNR) strains to assess the relative contributions of emotionality and conditionability to differences between the two Roman strains. The RHA learned significantly faster in active avoidance, but slightly slower in passive avoidance, significantly faster in acquisition of an active approach task, but slighty slower in extinction of active approach tasks despite extensive adaptation and gentling. The RHA showed more 'rearing', more activity in the open field and more variety-seeking. Crossing with MNR showed the RHA less reactive in the open field. Results show RLA equivocal in conditionability, more emotional, and perhaps less active.

Animals↗
PubMed1990

Some behavioural effects of captopril in rats.

1. Effects of inhibition of angiotensin converting enzyme (ACE, EC 3.4.15.1) in brain on psychomotor, exploratory, stereotyped and cognitive behaviour in rats were investigated. To inhibit brain ACE captopril (D-3-mercaptopropanoyl-L-proline) was given orally (p.o., 50 mg/kg) or intracerebroventricularly (i.c.v., 5 micrograms/rat). 3. Captopril given p.o. but not i.c.v. significantly enhanced stereotypy, overall number of conditioned avoidance responses, and decreased blood pressure. 4. No statistically significant influence of captopril given by either route on the number of crossings, rearings and bar approaches in the open field, performance of passive avoidance and number of correct choices as well as the speed of running for food in the T-maze was observed. 5. In conclusion, a small decrease of the activity of nigrostriatal dopaminergic system caused by the decrease of AII and/or increase of bradykinin, substance P, enkephalins and neurotensin in brain resulting from ACE inhibition is postulated.

Administration, Oral↗
PubMed1993

Administration of LHRH analog can improve working memory in aged female rats.

We had previously found that an age-related deficit in working memory appeared in middle-aged females, possibly related to their ageing reproductive system. This experiment investigates the effect of administering an analog of luteinizing hormone-releasing hormone (LHRH), D-Trp6-LHRH, to 22-mo-old female rats submitted to successive trainings in a water-reinforced matching to sample task since the age of three months. Animals were injected SC with a long-lasting microcapsule formulation (800 micrograms/kg continuously releasing 5 micrograms D-Trp6-LHRH per day for at least 28 days). The action of the analog on ovary weight and estradiol and progesterone levels was also studied. Administration of D-Trp6-LHRH counteracted the deleterious effect of age on performance and inhibited ovary function. However, hormone plasma levels were not modified. These results suggest that the hypothalamo-ovarian axis might be implicated in memory deficits of middle-aged females.

Aging↗