Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultrasonic vocalizations may be an expression of the affective pain response in laboratory animals. The present experiment compares the effects of morphine to the delta agonist, DPDPE (D-Pen2,D-Pen5 enkephalin) on a range of reflexive, behavioral and affective responses during an aggressive interaction. In experiment 1, naive female Long-Evans rats received morphine (0, 1, 3, 6, 10 micrograms ICV), or DPDPE (0, 30, 60, 100 micrograms ICV). In experiment 2, female rats were treated with naltrindole (1.0 mg/kg IP) 20 min before DPDPE (0, 60, 100 micrograms ICV). The following endpoints were measured: (1) latency to tail flick in response to heat stimuli; (2) high (33-65 kHz) and low (20-32 kHz) frequency ultrasonic and audible vocalizations; (3) defensive behavior; and (4) motoric activity. Following a brief exposure to attack, rats were threatened by the aggressor but protected from further attack by a large, wire mesh cage, thereby allowing for continued behavioral and vocal measurement without the risk of physical injury; video and audio recordings were made during the attack and then during a portion of the protected encounter (2 min). Morphine suppressed pain reactions varying in complexity from a spinal reflex, to an organized escape reaction, to an affective vocal response. The delta agonist, DPDPE, attenuated high frequency ultrasonic calling and tail flick responding. Defensive behaviors were also modulated by DPDPE at doses that had no effect on walking or rearing, indicating behavioral specificity. By contrast, doses of morphine that decreased defensive upright and escape also decreased motor activity. In female rats, morphine and DPDPE share a common profile of effects on a range of functional end-points, but DPDPE appears to modulate more selectively the reactions related to aversiveness without exerting sedative effects.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Delta opioid receptors: reflexive, defensive and vocal affective responses in female rats. 854 26

Taste-aversion (TA) learning was measured to determine whether exposure to high-voltage direct current (HVdc) static electric fields can produce TA learning in male Long Evans rats. Fifty-six rats were randomly distributed into four groups of 14 rats each. All rats were placed on a 20 min/day drinking schedule for 12 consecutive days prior to receiving five conditioning trials. During the conditioning trials, access to 0.1% sodium saccharin-flavored water was given for 20 min, followed 30 min later by one of four treatments. Two groups of 14 rats each were individually exposed to static electric fields and air ions, one group to +75 kV/m (+2 x 10(5) air ions/cm3) and the other group to -75 kV/m (-2 x 10(5) air ions/cm3). Two other groups of 14 rats each served as sham-exposed controls, with the following variation in one of the sham-exposed groups: This group was subdivided into two subsets of seven rats each, so that a positive control group could be included to validate the experimental design. The positive control group (n = 7) was injected with cyclophosphamide 25 mg/kg, i.p., 30 min after access to saccharin-flavored water on conditioning days, whereas the other subset of seven rats was similarly injected with an equivalent volume of saline. Access to saccharin-flavored water on conditioning days was followed by the treatments described above and was alternated daily with water "recovery" sessions in which the rats received access to water for 20 min in the home cage without further treatment. Following the last water-recovery session, a 20 min, two-bottle preference test (between water and saccharin-flavored water) was administered to each group. The positive control group did show TA learning, thus validating the experimental protocol. No saccharin-flavored water was consumed in the two-bottle preference test by the cyclophosphamide-injected, sham-exposed group compared to 74% consumed by the saline-injected sham-exposed controls (P < .0001). Saccharin-preference data for the static field-exposed groups showed no TA learning compared to data for sham-exposed controls. In summary, exposure to intense static electric fields and air ions did not produce TA learning as assessed by this particular design.
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PMID:Failure to produce taste-aversion learning in rats exposed to static electric fields and air ions. 855 31

Exposure to various aversive stimuli ('stressors') as well as positively-reinforcing stimuli has been shown to increase extracellular dopamine concentrations in terminal areas of the mesocorticolimbic dopamine system. The magnitude and site specificity of the dopaminergic response may depend on the nature of the aversive stimulus. In the present study, in vivo microdialysis was used to examine the effects of an ethologically relevant stressor, namely threat of social defeat, on dopamine concentrations in nucleus accumbens, striatum, and prefrontal cortex of freely-moving male Long-Evans rats. During the test session, dialysate and video recording samples were collected from previously-defeated 'intruder' rats in consecutive phases, while (1) in the home cage, (2) when placed in the empty, soiled cage of a resident rat which had previously defeated them, (3) when exposed to threat of defeat by the resident, and (4) when returned to their home cages. Control animals were not defeated; in this group of rats video recording and dialysate samples were obtained when they were placed into an empty, clean novel cage and later returned to their home cage. The results indicated that levels of dopamine were elevated to approximately 130% of baseline in nucleus accumbens and prefrontal cortex when rats were placed into either the resident or novel cage. In defeated intruders, extracellular dopamine levels in accumbens and prefrontal cortex were increased further (approximately 160% of baseline), during social threat; these biochemical changes were synchronous with high levels of orienting toward the resident but not with heightened motor activity. Extracellular dopamine levels in lateral striatum were not affected by either manipulation. These results suggest that altered accumbens and cortical extracellular dopamine concentrations during social threat are not secondary to motor activation but instead reflect increased attention to the provocative stimulus or attempts by the intruder to 'cope' with the stimulus.
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PMID:Social defeat stress selectively alters mesocorticolimbic dopamine release: an in vivo microdialysis study. 879 94

This study was performed to examine ethanol self-administration in rats bred for different sensitivities to the sedative effects of alcohol [the Colorado High Alcohol Sensitive (HAS) and Low Alcohol Sensitive (LAS) rats]. Four rats from each replicate line of the HAS and LAS rats (n = 16) were obtained from the University of Colorado, and initiation to self-administer ethanol by the sucrose-substitution procedure was attempted. Before the initiation procedure was conducted, home-cage ethanol intake and preference ratio did not differ between LAS and HAS rats. During the initiation procedure, the LAS rats came to self-administer 10% ethanol (v/v) at similar levels as outbred Wistar rats initiated with the same procedure (approximately 0.4 g/kg/session). The HAS rats, however, failed to initiate (approximately 0.08 g/kg/ session after completing the sucrose-substitution procedure) and lever pressing was reduced even more in the HAS rats when the ethanol concentration presented was > 10% (v/v). Three of the eight HAS rats stopped lever pressing completely when the ethanol concentration was raised to 15%. After initiation, home-cage preference ratio differed significantly between the LAS and HAS rats (LAS > HAS, p < 0.03). That the LAS rats did not consume greater amounts of ethanol compared with outbred Long-Evans or Wistar rats is contrary to our hypothesis, based on recent human data suggesting that a lower sensitivity to ethanol could result in increased alcohol intake. The finding that the HAS rats could not be initiated, while selectively bred ethanol nonpreferring rats can, is also contrary to our hypothesis. Further studies related to ethanol self-administration with the HAS line could provide important information related to the genetics of alcohol nonacceptance.
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PMID:Initiation of ethanol self-administration by the sucrose-substitution method with HAS and LAS rats. 880 Mar 84

The effect of social confrontation on the susceptibility to metastatic development was studied in rats. An intruder male Fischer 344 (F344) was introduced to a male-female Long-Evans pair and the behavior was recorded during the first 30 min of a 7-h confrontation session. Mammary tumor cells (MADB106), syngeneic to the inbred F344 rat, were injected i.v. to the intruder 1 h after the beginning of the confrontation session, and the lung retention of tumor cells was determined 24 h later. In this tumor model, metastases develop only in the lungs. Retention of tumor cells and the consequent development of lung colonies are known to be highly controlled by the activity levels of natural killer cells during the first 24 h after tumor inoculation but not later. Twenty of the 21 intruders were attacked by resident males and 19 displayed submissive behavior. A significant increase in lung tumor retention was evident in intruders compared to both control groups: home cage and new environment. The magnitude of this increase was higher in intruders that frequently displayed submissive behavior (indicating social defeat). Pretreatment with the beta-adrenergic antagonist, butoxamine, reduced the effects of social confrontation by approximately 50%, and adrenal demedullation almost abolished it without significantly affecting the social interaction. These findings suggest that the nature of intruder-resident interaction, rather than being subdominant or exposure to an unfamiliar environment, has a marked influence on the intruder's susceptibility to metastatic development. These effects of social confrontation seem to be mediated by adrenergic mechanisms, possibly via adrenergic influence on NK function and distribution.
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PMID:Social confrontation and tumor metastasis in rats: defeat and beta-adrenergic mechanisms. 880 76

The effects of amygdala lesions on passive avoidance of drinking (dPA) and social interactions in a resident-intruder test were examined in two experiments that utilized different lines of Long-Evans hooded rats. The lesions were fairly well restricted to the rostral half of the central nucleus (rACe), or the cholinergically richly innervated basolateral nucleus (ABL) or the medial nucleus (AMe) of the amygdala. In both experiments, dPA deficits indicating disturbances in fear conditioning or fear expression were found with ABL and rACe lesions. The rACe lesions produced a greater deficit. AMe lesions caused no dPA deficit at all, which contrasts with the mild PA deficits reported by others employing larger lesions extending to the cortical nucleus and, perhaps, damaging the central nucleus. Social behavior was not affected by the lesions in any clear manner. In rats from a long-standing home colony, rACe lesions increased a behavior of plowing and kicking the wood-chip cage bedding during social encounters, and AMe lesions increased lateral defense behaviors. Both effects are paradoxical, suggesting increased anxiety in the fear-deficient rACe rats and increased defense with AMe lesions, despite several previous reports of decreased defense. In the second experiment, rats purchased from a supplier showed no lesion effects during social interactions; like the control group, all three lesion groups exhibited increases in offense associated with cohabitation with a female. The ABL lesions, particularly, had no effect comparable to the decreased offense recently reported to occur following neurotoxin lesions.
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PMID:Effects of small amygdala lesions on fear, but not aggression, in the rat. 897 32

Nicotine has been shown to maintain intravenous self-administration behaviour in humans and laboratory animals. However, factors critical in the initiation of nicotine self administration are not well defined. In particular genetic differences and effects of pre-exposure to nicotine have not been examined. Male Sprague-Dawley or Long-Evans rats were surgically prepared with indwelling jugular catheters and 3 days later received chronic injections of nicotine (0.4 mg/kg SC) or vehicle (saline, 1 ml/kg) for 7 days in their home cage. The next day, 2-h daily test sessions were initiated, during which rats were given the opportunity to nose-poke for nicotine infusions (0.015, 0.03 or 0.06 mg/kg per infusion) under a one-response fixed-ratio (FR-1) schedule of reinforcement with a 20-s time out after each infusion. One hole was defined as active while pokes in the other hole were recorded but had no scheduled consequence. The response requirement was increased progressively to five (FR-5) over successive sessions. Both saline- and nicotine-pretreated Sprague-Dawley rats showed a preference for the active hole, while only the saline-pretreated Long-Evans rats acquired the self-administration as defined by significant differences between responding in the active versus the inactive holes. The Fisher (F344) and Lewis inbred strains also failed to acquire self-administration of nicotine under these conditions. With Sprague-Dawley and Long-Evans rats that acquired the self-administration, and showed stable levels of maintained responding for nicotine, substituting saline for the nicotine or pretreating with mecamylamine (2.0 mg/kg SC) extinguished the behaviour. When dose per infusion was varied, an inverted U-shaped dose-response curve was obtained. These results support previous reports that nicotine can serve as a reinforcer in rodents and demonstrate that environmental factors such as prior nicotine exposure or genetic factors such as rat strain can affect acquisition of nicotine self-administration.
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PMID:Nicotine self-administration in rats: strain and nicotine pre-exposure effects on acquisition. 912 61

Mother-infant interaction was observed in Long-Evans and Fischer 344 rats after fostering within or across strains. Interactions immediately following introduction of foster pups to the cage as well as undisturbed interactions with resident litters were examined. Some differences were related to alien status, some to strain of pups, and others to strain of dams. Greater responsiveness to pups of the maternal strain was exhibited in retrieval and body licking. Long-Evans pups received more crouching from dams of both strains 3-12 days postpartum, perhaps because they are significantly larger. Regardless of pup strain, Long-Evans dams engaged in more maternal licking than did F344 dams, and this was more likely directed to the anogenital region. Dams of both strains were more likely to lick male than female pups, regardless of pup strain. The strain difference in maternal licking is consistent with adult strain differences in water and salt appetite and may contribute developmentally to the superior copulatory performance of Long-Evans males.
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PMID:Mother-infant interactions in two strains of rats: implications for dissociating mechanism and function of a maternal pattern. 914 6

Electrolytic lesions aimed at the suprachiasmatic nuclei (SCN) were made in male Long-Evans rats. Body temperature (Tb), activity, and drinking were monitored continuously in a 12-h light:12-h dark (12:12 LD) cycle at an ambient temperature of 23 degrees C. Large SCN lesions eliminated activity and drinking rhythms and abolished or reduced the circadian rhythm of Tb. The Tb responses of the rats were measured in L after exposure to cold and injection of lipopolysaccharide (LPS), a fever-producing drug, and in both L and D during a 30-min exposure to a novel cage. Rats with SCN lesions (SCNX) maintained their Tb as well as did controls during 2-h exposure to 2 degrees C. They also showed the expected increases in Tb in response to novelty and LPS. Nevertheless, there were differences between SCNX rats and other rats. When measured 9 h after LPS injection, SCNX rats had lower Tb in D than did sham-lesioned or intact rats or rats with lesions that missed the SCN. This is not surprising; the Tb of SCNX rats does not go as high as that of intact rats in D. However, it was surprising that at night SCNX rats increased their Tb in response to novelty (lights on in the test situation), whereas normal rats did not. For some reason, light inhibits the Tb rise to novelty in normal rats but does not do so in rats with SCN lesions.
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PMID:Suprachiasmatic nuclei lesions do not eliminate homeostatic thermoregulatory responses in rats. 918 34

The influence of proximal olfactory cues on place learning and memory was tested in two different spatial tasks. Rats were trained to find a hole leading to their home cage or a single food source in an array of petri dishes. The two apparatuses differed both by the type of reinforcement (return to the home cage or food reward) and the local characteristics of the goal (masked holes or salient dishes). In both cases, the goal was in a fixed location relative to distant visual landmarks and could be marked by a local olfactory cue. Thus, the position of the goal was defined by two sets of redundant cues, each of which was sufficient to allow the discrimination of the goal location. These experiments were conducted with two strains of hooded rats (Long-Evans and PVG), which show different speeds of acquisition in place learning tasks. They revealed that the presence of an olfactory cue marking the goal facilitated learning of its location and that the facilitation persisted after the removal of the cue. Thus, the proximal olfactory cue appeared to potentiate learning and memory of the goal location relative to distant environmental cues. This facilitating effect was only detected when the expression of spatial memory was not already optimal, i.e., during the early phase of acquisition. It was not limited to a particular strain.
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PMID:Olfactory cues potentiate learning of distant visuospatial information. 932 57


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