| 1. |
- Bergvall, A H, et al.
(författare)
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An animal model for type 2 alcoholism? Alcohol consumption and aggressive behavior following lesions in the raphe nuclei, medial hypothalamus, or ventral striatum-septal area.
- 1996
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Ingår i: Physiology & behavior. - 0031-9384. ; 60:4, s. 1125-35
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Tidskriftsartikel (refereegranskat)abstract
- Given the conspicuous association between aggressive antisocial traits and alcoholism in men, we investigated whether or not a link between defensive aggressive behavior and homecage alcohol consumption could be demonstrated in the laboratory rat. This was accomplished by observing ethanol intake and hyperreactivity towards the experimenter in rats made hyperdefensive by brain lesions. Rats with medial hypothalamic electrocoagulations showed a remarkable degree of hyperdefensiveness, lasting throughout the entire 6-week postoperative period. Alcohol intake, on the other hand, was not different from sham-operated controls when the beverage was offered as a plain 6% solution or in a 0.2% saccharin vehicle. When subjected to the stress of food restriction, which enhances ethanol intake in normal rats, medial hypothalamic subjects actually decreased their alcohol consumption. Electrolytic lesions in the dorsal and median raphe brought about a transient increase in defensive aggression, but no alteration in ethanol drinking. Animals with ibotenic acid-induced extensive lesions to the ventral striatum and septal area were not only viciously aggressive, but also drank considerably more alcohol than controls. Ibotenic acid-lesioned rats did not respond to the saccharin or food-restriction conditions by increasing their alcohol intake further, perhaps because they drank at a maximal rate already during the plain ethanol-phase of the experiment. These observations show that basal forebrain dysfunction in the rat can give rise to excessive alcohol intake and heightened aggression, a constellation of behavioral symptoms observed in male type 2 alcoholics.
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| 2. |
- Bergvall, A H, et al.
(författare)
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In quest for a possible association between heightened social aggression and excessive alcohol drinking in the rat.
- 1996
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Ingår i: Physiology & behavior. - 0031-9384. ; 59:4-5, s. 807-12
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Tidskriftsartikel (refereegranskat)abstract
- Many clinical studies show that a sizeable proportion of male alcoholics are also inclined to act violently and aggressively. Given this association in humans, we asked whether a relationship exists between ethanol intake and aggressive behaviour in laboratory rats. In a first test of the hypothesis, we measured ethanol intake in male rats made aggressive by periodic contacts with sexually active females. Although the males became significantly more aggressive, there was no concomitant enhancement of alcohol consumption. In another experiment, observations of ethanol drinking in lactating rats exhibiting maternal aggression revealed no alteration in ethanol intake relative to nonlactating control females. However, because water intake was substantially elevated in the maternal rats, there was a net decrease in ethanol preference. The final experiment examined aggressiveness in chronically food-restricted male rats. In line with previous studies, this procedure increased ethanol drinking, but it did not enhance aggressive behaviour. It is concluded that, in our rats, there is no apparent association between the level of social aggression and the voluntary intake of ethanol in a two-bottle choice paradigm. The possibility remains, though, that alcohol drinking is better related to other forms of aggression, such as defensive or predatory aggression.
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| 3. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Alcohol responsiveness, hyperreactivity, and motor restlessness in an animal model for attention-deficit hyperactivity disorder.
- 1999
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Ingår i: Psychopharmacology. - 0033-3158. ; 146:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Attention-deficit hyperactivity disorder and related pervasive developmental disorders constitute risk factors for adult alcohol abuse and antisocial behaviours, including violent offending.The present study assessed alcohol responsiveness and hyperemotionality in neonatally 6-OHDA-treated rats, which provides an animal model for attention-deficit hyperactivity disorder.Male Wistar rats were given intracerebroventricular 6-OHDA (100 microg/5 microl) or vehicle (saline-ascorbic acid) on postnatal day 3. In adulthood, we measured motor activity, defensive behaviours and ethanol responsiveness.6-OHDA resulted in depletions of brain catecholamine levels. The experimental animals were markedly hyperactive, showed increases in active defensive behaviours (fleeing) and decreases in passive defensive responses (freezing) in response to an sudden auditory signal. In tests for reactivity to the experimenter (i.e. defensiveness to innocuous stimuli), 6-OHDA rats were hyperreactive in comparison to controls. With regard to home cage 6% ethanol and water consumption, there were no differences between experimental and control rats. However, 6-OHDA rats displayed a remarkable resistance to the motor-impairing effect of alcohol (0.5-1.0 g/kg, IP). A similar hyposensitivity to the motor-suppressive effect of diazepam (5.0 mg/kg, IP) was also found.The present results show that adult rats exposed to 6-OHDA as neonates are motorically restless, unusually prone to respond defensively to innocuous stimuli, and considerably less sensitive to the intoxicating effects of ethanol and diazepam.
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| 4. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Amphetamine-induced hyperactivity: differences between rats with high or low preference for alcohol.
- 1995
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Ingår i: Alcohol (Fayetteville, N.Y.). - 0741-8329. ; 12:4, s. 363-7
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Tidskriftsartikel (refereegranskat)abstract
- This study determined the relationship between ethanol intake and spontaneous and amphetamine-induced locomotor activity. Locomotion was studied in high-preferring (HP; > 70% of total fluid intake consumed as alcohol) and low-preferring (LP; < 20% of total fluid intake consumed as alcohol) male Wistar rats with free access to water and a 6% (v/v) ethanol solution for 3 weeks. Following an alcohol-free 3-week period, the animals were tested for spontaneous motor activity for 1 h. One week later, locomotion was recorded in the same activity boxes following a subcutaneous injection with d-amphetamine sulfate (1 mg/kg). For determination of plasma levels of corticosterone, blood samples were taken immediately after each of the two tests for locomotor activity. There was no difference between HP and LP rats with regard to spontaneous locomotor activity. Neither were there any differences in plasma levels of corticosterone between the groups. Amphetamine stimulated locomotion in both HP and LP rats, but to a significantly greater extent in HP animals. Both groups had higher blood levels of corticosterone after the amphetamine test than after the drug-free test, but the corticosterone increase was significantly larger in the HP than in the LP rats. These data indicate that the same neural substrate (e.g., the mesocorticolimbic dopamine system) may mediate important aspects of both ethanol drinking and amphetamine responsiveness. Individual differences in the properties of this substrate may account for the finding that ethanol drinking and amphetamine responsiveness covary. A possible explanation for this association may be that prior consumption of ethanol sensitizes the neural substrate responsible for amphetamine-induced hyperactivity.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 5. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Consequence of long-term exposure to corticosterone or dexamethasone on ethanol consumption in the adrenalectomized rat, and the effect of type I and type II corticosteroid receptor antagonists.
- 1995
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Ingår i: Psychopharmacology. - 0033-3158. ; 117:2, s. 216-24
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Tidskriftsartikel (refereegranskat)abstract
- The daily fluid intake of male Wistar rats with simultaneous access to 6% ethanol and water was determined during a baseline period (1 week), following adrenalectomy (1 week) and for 3 weeks following SC implantation of hormone pellets containing corticosterone (CORT) or dexamethasone (DEX). Ethanol consumption dropped during the first week of adrenalectomy (ADX) but increased again in the absence of hormone replacement to reach preoperative levels during the ensuing weeks. The CORT treatment, which produced plasma hormone levels similar to the 24-h mean concentration of adrenally intact rats, not only reversed the effect of ADX on alcohol consumption but also enhanced it to levels above those observed in intact rats. Water intake was not affected by the CORT treatment. DEX implants stimulated water intake, but did not enhance the drinking of ethanol. SC injections of RU 28318 (type I corticosterone receptor antagonist; 10 mg/kg) or mifepristone (RU 38486; type II receptor antagonist; 25 mg/kg) at the beginning and halfway through three daily, 6-h tests failed to affect ethanol drinking in adrenally intact rats or in ADX rats bearing CORT implants. Similarly, there was no effect of giving the two antagonists in combination. These results suggest that exogenous CORT can induce excessive alcohol intake in genetically unselected rats and that this facilitatory effect may be mediated by non-genomic cellular mechanisms.
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| 6. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Dokumentation av alkoholbruk och dess konsekvenser
- 1997
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Ingår i: Alkohol: Ett psykosocialt, beteende- och samhällsvetenskapligt perspektiv. - : Lund: Studentlitteratur. - 9144604211 - 9789144604213
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Effect of local intracerebral corticosterone implants on alcohol intake in the rat.
- 1999
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Ingår i: Alcohol and alcoholism (Oxford, Oxfordshire). - 0735-0414. ; 34:6, s. 851-61
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Tidskriftsartikel (refereegranskat)abstract
- Corticosterone acts within the brain to stimulate alcohol consumption in the rat. The experiments reported here were aimed at identifying where in the brain corticosterone acts to facilitate ethanol drinking. The daily fluid intake of male Wistar rats with simultaneous access to 6% ethanol and water was determined during a 1-week pre-operative baseline period and following implantation of corticosterone in various brain areas. Animals bearing unilateral or bilateral implants of corticosterone in the ventral striatum showed increased ethanol consumption compared to cholesterol-treated controls. Ethanol intake was not affected when corticosterone was implanted into septum, hippocampus, or thalamus. Neither were changes in fluid intake detected in animals bearing ventral striatal implants of two related steroid hormones, aldosterone and testosterone. These results indicate that corticosterone partly acts within the ventral striatopallidal system to facilitate alcohol consumption in the rat.
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| 8. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Effects of early weaning and social isolation on subsequent alcohol intake in rats.
- 1997
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Ingår i: Alcohol (Fayetteville, N.Y.). - 0741-8329. ; 14:2, s. 175-80
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the influence of early weaning and separation from mother and littermates on voluntary ethanol intake and general activity during prepuberal age, and adult age corticosterone levels. On day 16 after birth the male offspring of a litter were divided in three groups, each subjected to a different rearing condition: 1)early weaned and isolated from its littermates; 2) early weaned but growing up together with two littermates; 3) staying with mother and two littermates. On day 25 the animals were tested for general activity including assessment of fearfulness. From day 30 all animals were given a free choice between water and ethanol solution. The ethanol concentration was increased by 2% during each of the following weeks until 10% was reached during the 5th week. Ten days later, after cessation of alcohol testing, blood samples were taken from the tail for assessment of plasma levels corticosterone. The isolated, early weaning pups displayed higher activity levels than both normally reared pups and group-living, early weaning pups. The quotient peripheral locomotion/total locomotion was lower for the isolated pups compared with the other groups, suggesting less fearfulness in the early weaned, isolated pups. For 2%, 4%, and 6% ethanol solutions the normal-reared rats consumed more ethanol and displayed higher ethanol preference than either of the early weaned groups of animals. No group differences were observed either at 8% or 10% ethanol solutions. Levels of plasma corticosterone in adult age in the early weaned rats were slightly reduced, not reaching statistical significance, compared to the normally weaned animals.
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| 9. |
- Fahlke, Claudia, 1964, et al.
(författare)
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Facilitation of ethanol consumption by intracerebroventricular infusions of corticosterone.
- 1996
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Ingår i: Psychopharmacology. - 0033-3158. ; 127:2, s. 133-9
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Tidskriftsartikel (refereegranskat)abstract
- Male Wistar rats bearing intracerebroventricular (ICV) cannulae and with simultaneous access to 6% ethanol and water were subjected to adrenalectomy (ADX) or sham surgery. ADX decreased ethanol intake. Starting a few days later, the animals received ICV infusions with 100 micrograms corticosterone acetate (CORT) with 2-to 3-day intervals for 2 weeks. ICV CORT, but not SC CORT at the same dose, restored ethanol consumption in ADX rats to preoperative levels, whereas vehicle infusions (propylene glycol) did not. Adrenally intact animals, which normally consumed moderate amounts of ethanol (approximately 0.5 g/kg per day), also showed a robust effect of ICV infusions of CORT, whereas this facilitatory effect was not observed in high consumers (approximately 3.0 g/kg per day). The suppressive effect of ADX on ethanol intake was not reproduced by concurrent and repeated ICV infusions of intracellular mineralocorticoid (RU 28318) and glucocorticoid (mifepristone) receptor blockers. It is concluded that CORT stimulates alcohol consumption by acting in the brain, probably by way of neuronal membrane mechanisms.
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| 10. |
- Fahlke, Claudia, 1964
(författare)
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Mångdimensionellt område
- 1997
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Ingår i: Alkohol: Ett psykosocialt, beteende- och samhällsvetenskapligt perspektiv. - : Lund: Studentlitteratur. - 9144604211 - 9789144604213
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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