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Katsouni E, Zarros A, Skandali N, Tsakiris S, Lappas D. The role of cholecystokinin in the induction of aggressive behavior: a focus on the available experimental data (review). ACTA ACUST UNITED AC 2014; 100:361-77. [PMID: 24317345 DOI: 10.1556/aphysiol.100.2013.4.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cholecystokinin (CCK) is a neuropeptide that is (among others) reportedly involved in the pathophysiology of psychiatric disorders. The excitatory role of CCK in negative affective emotions as well as in aversive reactions, antisocial behaviors and memories, has been indicated by numerous electrophysiological, neurochemical and behavioral methodologies on both animal models for anxiety and human studies. The current review article summarizes the existing experimental evidence with regards to the role of CCK in the induction of aggressive behavior, and: (a) synopsizes the anatomical circuits through which it could potentially mediate all types of aggressive behavior, as well as (b) highlights the potential use of these experimental evidence in the current research quest for the clinical treatment of mood and anxiety disorders.
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Affiliation(s)
- E Katsouni
- University of Oxford Worcester College Oxford UK National and Kapodistrian University of Athens Laboratory of Physiology, Medical School PO Box 65257 GR-15401 Athens Greece
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2
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Abramov U, Raud S, Innos J, Lasner H, Kurrikoff K, Türna T, Puussaar T, Õkva K, Matsui T, Vasar E. Different housing conditions alter the behavioural phenotype of CCK2 receptor-deficient mice. Behav Brain Res 2008; 193:108-16. [DOI: 10.1016/j.bbr.2008.04.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 04/25/2008] [Accepted: 04/29/2008] [Indexed: 01/22/2023]
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3
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Hansen TVO, Borup R, Marstrand T, Rehfeld JF, Nielsen FC. Cholecystokinin-2 receptor mediated gene expression in neuronal PC12 cells. J Neurochem 2007; 104:1450-65. [DOI: 10.1111/j.1471-4159.2007.05076.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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4
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Kolik LG, Zhukov VN, Seredenin SB. Effect of compound GB-115 on morphine-induced analgesia. Bull Exp Biol Med 2007; 143:703-5. [DOI: 10.1007/s10517-007-0219-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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5
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Rünkorg K, Värv S, Matsui T, Kõks S, Vasar E. Differences in behavioural effects of amphetamine and dopamine-related gene expression in wild-type and homozygous CCK2 receptor deficient mice. Neurosci Lett 2006; 406:17-22. [PMID: 16916582 DOI: 10.1016/j.neulet.2006.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 07/03/2006] [Accepted: 07/06/2006] [Indexed: 11/28/2022]
Abstract
Neuropeptide cholecystokinin (CCK) interacts with dopamine in the regulation of motor activity and motivations. Therefore, in CCK(2) receptor deficient mice the behavioural effects of repeated amphetamine administration and changes in dopamine-related gene expression were studied. Four-day amphetamine (1 mg/kg) treatment induced a significantly stronger motor sensitization in homozygous mice compared to their wild-type littermates. However, in the conditioned place preference test the action of amphetamine was more pronounced in wild-type animals. As opposed to wild-type mice, amphetamine (1-3 mg/kg) did not cause a significant conditioned place preference in homozygous mice. The expression of Tyhy gene was elevated in the mesolimbic structures and Drd2 gene was down-regulated in the mesencephalon of saline-treated homozygous mice in comparison with respective wild-type group. Four-day treatment with amphetamine induced a significant increase in the expression of Tyhy in the mesencephalon, striatum and mesolimbic structures of wild-type mice, whereas in homozygous mice a similar change was evident only in the mesencephalon. Also, the expression of Drd1 gene in the striatum and Drd2 gene in the mesolimbic structures of wild-type mice were up-regulated under the influence of amphetamine. In conclusion, the present study established differences in the behavioural effects of amphetamine in wild-type and homozygous mice. The increased tone of dopaminergic projections from the mesencephalon to mesolimbic structures is probably related to increased amphetamine-induced motor sensitization in homozygous mice. The lack of development of up-regulation of Drd1 and Drd2 genes after repeated treatment with amphetamine probably explains the reduced place conditioning in CCK(2) receptor deficient mice.
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MESH Headings
- Amphetamine/pharmacology
- Amphetamine-Related Disorders/genetics
- Amphetamine-Related Disorders/metabolism
- Amphetamine-Related Disorders/physiopathology
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Brain/drug effects
- Brain/metabolism
- Brain/physiopathology
- Cholecystokinin/metabolism
- Conditioning, Psychological/drug effects
- Conditioning, Psychological/physiology
- Disease Models, Animal
- Dopamine/metabolism
- Dopamine Uptake Inhibitors/pharmacology
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Homozygote
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neural Pathways/drug effects
- Neural Pathways/metabolism
- Neural Pathways/physiopathology
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Nucleus Accumbens/physiopathology
- Receptor, Cholecystokinin B/drug effects
- Receptor, Cholecystokinin B/genetics
- Receptor, Cholecystokinin B/metabolism
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/metabolism
- Tyrosine 3-Monooxygenase/genetics
- Up-Regulation/drug effects
- Up-Regulation/genetics
- Ventral Tegmental Area/drug effects
- Ventral Tegmental Area/metabolism
- Ventral Tegmental Area/physiopathology
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Affiliation(s)
- Kertu Rünkorg
- Department of Physiology, University of Tartu, Ravila 19, Tartu 50411, Estonia.
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6
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Abramov U, Raud S, Innos J, Kõks S, Matsui T, Vasar E. Gender specific effects of ethanol in mice, lacking CCK2 receptors. Behav Brain Res 2006; 175:149-56. [PMID: 16970998 DOI: 10.1016/j.bbr.2006.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 08/11/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
Neuropeptide cholecystokinin (CCK) has been reported to suppress ethanol intake, but there is contradictory evidence about the role of CCK(2) receptors. In the present study anxiolytic, hypolocomotor and sedative effects of acute ethanol administration, but also voluntary ethanol consumption were studied in male and female mice, lacking CCK(2) receptors (-/-). Ethanol (1.0 and 2.0 g/kg) induced a significant reduction of anxiety-related behaviours in the elevated plus-maze, but this effect was statistically significant only in female homozygous mice (-/-). In male mice, lacking CCK(2) receptors (-/-), but not in their wild-type littermates (+/+), the suppression of vertical locomotor activity was caused by ethanol at a dose 0.5 g/kg. The highest dose of ethanol (2.0 g/kg) produced statistically significant reduction of horizontal locomotor activity only in female wild-type (+/+) mice, but this effect was related to increased basal activity when compared to female mutant (-/-) mice. Duration of the loss of righting reflex was not significantly affected by genotype or gender, but blood ethanol levels at regain of righting reflex were significantly lower in female homozygous mice (-/-) compared to their wild-type (+/+) littermates, indicating increased sensitivity to the sedative effect of ethanol. Ethanol intake, but not preference, at concentration 10% was significantly increased in female mice, lacking CCK(2) receptors (-/-). The present study revealed an altered response to the acute effects of ethanol in CCK(2) receptor deficient mice (-/-). These changes are gender-specific and could be attributed to the altered activity of dopaminergic system in male mice and increased activity of GABA-ergic system in female mice as established in our previous studies.
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Affiliation(s)
- Urho Abramov
- Department of Physiology, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia.
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7
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Roots K, Kairane C, Salum T, Kõks S, Karelson E, Vasar E, Zilmer M. Very low levels of cholecystokinin octapeptide activate Na‐pump in the cerebral cortex of CCK2receptor‐deficient mice. Int J Dev Neurosci 2006; 24:395-400. [PMID: 16822640 DOI: 10.1016/j.ijdevneu.2006.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 05/10/2006] [Accepted: 05/23/2006] [Indexed: 11/20/2022] Open
Abstract
This study provides the first evidence that CCK-8 (0.01 pM to 0.1 mM) stimulates Na,K-ATPase in the cortical membranes of wild-type and CCK(2) receptor-deficient mice. In each genotype, the maximal stimulation was about 40%. Homozygous mice revealed substantially lower EC50 (4 pM) than heterozygous (37 pM) or wild-type animals (682 pM). In homozygous CCK2 receptor-deficient mice, the expression of CCK1 receptor gene was 5-fold higher than in wild-type animals. CCK1 receptor antagonist devazepide counteracted effect of CCK-8 in all three genotypes, whereas CCK2 receptor antagonist L-365, 260 showed significant antagonism in wild-type and heterozygous mice. The cooperativity of Na,K-ATPase for Na+, but not for K+, was lost in homozygous mice. Altogether, very low concentrations of CCK-8 via CCK1 and CCK2 receptors stimulate Na,K-ATPase in the cerebral cortex. CCK2 receptor-deficiency leads to the altered functionality of Na,K-ATPase that might be compensated by CCK1 receptor mediated influence of CCK (and its agonists) on the enzyme.
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Affiliation(s)
- Kristiina Roots
- Department of Biochemistry, Tartu University, Ravila 19, 50411 Tartu, Estonia
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8
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Raud S, Innos J, Abramov U, Reimets A, Kõks S, Soosaar A, Matsui T, Vasar E. Targeted invalidation of CCK2 receptor gene induces anxiolytic-like action in light-dark exploration, but not in fear conditioning test. Psychopharmacology (Berl) 2005; 181:347-57. [PMID: 15830228 DOI: 10.1007/s00213-005-2255-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Accepted: 02/24/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE Evidence suggests that gamma-aminobutyric acid (GABA) and cholecystokinin (CCK) have opposite roles in the regulation of anxiety. OBJECTIVES The aim of our work was to study the behaviour of CCK(2) receptor deficient mice in light-dark exploration and fear conditioning tests. Moreover, the action of diazepam and methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM), having the opposite effect on GABA(A) receptors, was evaluated on the exploratory behaviour in these mice. Expression levels of GABA(A) receptor subunit genes were also measured. METHODS Light-dark exploration and fear conditioning tests were used to determine changes in anxiety of mice. The action of diazepam (0.5-2 mg/kg i.p.) and DMCM (0.25-1 mg/kg i.p.) was studied in the light-dark box. The effect of DMCM was also evaluated in the motor activity test to demonstrate that its anti-exploratory action was not related to motor suppression. Expression levels of GABA(A) receptor subunit genes were determined by means of real-time polymerase chain reaction (qRT-PCR). RESULTS Female mice lacking CCK(2) receptors displayed increased exploratory activity in the light-dark box compared to their wild-type (+/+) littermates. Locomotor activity in the motility boxes and the intensity of freezing did not differ in wild-type (+/+) and homozygous (-/-) mice. Treatment with diazepam (0.5 mg/kg) increased the number of transitions in wild-type (+/+) animals, whereas in homozygous (-/-) mice diazepam (0.5-2 mg/kg) reduced exploratory activity. Administration of DMCM (0.25-1 mg/kg) induced an anxiogenic-like effect in homozygous (-/-) mice, but did not change their locomotor activity. Gene expression analysis established a 1.6-fold increase in the expression of the alpha2 subunit of GABA(A) receptors in the frontal cortex of homozygous (-/-) mice. CONCLUSION Genetic invalidation of CCK(2) receptors induced an anxiolytic-like action in exploratory, but not in conditioned models of anxiety. The observed reduction in anxiety in homozygous (-/-) mice is probably related to an increased function of GABAergic system in the brain.
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Affiliation(s)
- Sirli Raud
- Department of Physiology, Biomedicum, University of Tartu, Estonia
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9
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van den Buuse M, van Driel IR, Samuelson LC, Pijnappel M, Martin S. Reduced effects of amphetamine on prepulse inhibition of startle in gastrin-deficient mice. Neurosci Lett 2005; 373:237-42. [PMID: 15619550 DOI: 10.1016/j.neulet.2004.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Revised: 09/27/2004] [Accepted: 10/05/2004] [Indexed: 10/26/2022]
Abstract
The present study was aimed at investigating the role of gastrin in startle, startle habituation and prepulse inhibition (PPI). There were no significant differences between gastrin knockout mice and their wildtype controls in any of these baseline parameters. The disruption of PPI by treatment with 5 mg/kg of amphetamine was absent in gastrin knockout mice. However, a higher dose of amphetamine disrupted PPI in both genotypes. Similarly, treatment with the dopamine receptor agonist, apomorphine, the N-methyl-D-aspartate receptor antagonist, MK-801, and the serotonin-1A receptor agonist, 8-hydroxy-di-propylaminotetralin (8-OH-DPAT) modulated PPI similarly in gastrin knockout mice and wildtype controls. These data suggest a role of gastrin in the brain in modulating dopamine release in areas involved in PPI.
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Affiliation(s)
- Maarten van den Buuse
- Behavioural Neuroscience Laboratory, Mental Health Research Institute of Victoria, 155 Oak Street, Parkville, Vic. 3052, Australia.
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Abramov U, Raud S, Kõks S, Innos J, Kurrikoff K, Matsui T, Vasar E. Targeted mutation of CCK(2) receptor gene antagonises behavioural changes induced by social isolation in female, but not in male mice. Behav Brain Res 2004; 155:1-11. [PMID: 15325774 DOI: 10.1016/j.bbr.2004.03.027] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Revised: 03/26/2004] [Accepted: 03/29/2004] [Indexed: 11/25/2022]
Abstract
Neuropeptide cholecystokinin (CCK) regulates the adaptation of rodents in the novel environment. In the present study we analysed the behavioural changes induced by the individual housing in mice, lacking CCK(2) receptors. The wild-type (+/+) and homozygous (-/-) CCK(2) receptor deficient mice of both gender were used throughout the study. The weight gain during the 21-day isolation period and changes in the locomotor activity following the social separation were measured. The elevated plus-maze and resident/intruder tests were also performed to test alterations in the emotional behaviour. Social isolation induced locomotor hyperactivity, reduced weight gain and increased aggressiveness in the wild-type (+/+) and homozygous (-/-) male mice. In the wild-type (+/+) female mice the significant reduction of exploratory activity in the plus-maze was evident. By contrast, in female mice, lacking CCK(2) receptors, the exploration of the plus-maze was not significantly affected by the individual housing. This finding demonstrates that the social isolation does not cause anxiety-like state in the CCK(2) receptor deficient mice. Moreover, the targeted invalidation of CCK(2) receptors increased in male mice the affinity of dopamine D(2) receptors in the sub-cortical structures, whereas in female mice the increased affinity of 5-hydroxytryptamine(2) (5-HT(2)) receptors in the frontal cortex was established. The increased affinity of 5-HT(2) receptors is probably the compensatory change to the lack of CCK(2) receptors in female mice and probably reflects the reduced sensitivity of these animals to the anxiogenic manipulations. In conclusion, targeted mutation of CCK(2) receptors selectively antagonised the behavioural changes induced by the individual housing in females, but not in male mice.
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Affiliation(s)
- Urho Abramov
- Department of Physiology, Biomedicum, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia
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11
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Alttoa A, Harro J. Effect of CCK1 and CCK2 receptor blockade on amphetamine-stimulated exploratory behavior and sensitization to amphetamine. Eur Neuropsychopharmacol 2004; 14:324-31. [PMID: 15163443 DOI: 10.1016/j.euroneuro.2003.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Revised: 06/17/2003] [Accepted: 09/30/2003] [Indexed: 10/26/2022]
Abstract
Interactions between dopaminergic neurotransmission and cholecystokinin (CCK) in the CNS may be important in the pathogenesis of psychotic disorders and substance abuse. In this study, the effect of coadministration of the selective CCK receptor antagonists devazepide and L-365,260 (for selectively blocking CCK1 and CCK2 receptors, respectively), on the effect of amphetamine on the rat exploratory behavior, and on sensitization of locomotor response to amphetamine, were studied. Amphetamine (0.5 mg/kg) increased exploratory activity in the exploration box for 5 consecutive testing days, while devazepide (10 microg/kg) blocked and L-365,260 (10 microg/kg) enhanced amphetamine-induced stimulation of activity. Devazepide coadministration prevented the development of sensitization to amphetamine, while coadministration of L-365,260 with amphetamine potentiated the locomotor effect of a challenge dose of amphetamine. These results suggest that endogenous CCK, released during exploratory activity, shapes behavioral responses to amphetamine by acting on both receptor subtypes, and modulates the development of sensitization to amphetamine.
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Affiliation(s)
- Aet Alttoa
- Department of Psychology, Center of Behavioral and Health Sciences, Tartu University, Tiigi 78, 50410 Tartu, Estonia
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12
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Rünkorg K, Veraksits A, Kurrikoff K, Luuk H, Raud S, Abramov U, Matsui T, Bourin M, Kõks S, Vasar E. Distinct changes in the behavioural effects of morphine and naloxone in CCK2 receptor-deficient mice. Behav Brain Res 2003; 144:125-35. [PMID: 12946603 DOI: 10.1016/s0166-4328(03)00070-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of morphine, mu-opioid receptor agonist, and naloxone, a non-selective opioid receptor antagonist, in the locomotor activity and place conditioning tests were studied in the CCK(2) receptor-deficient male mice. The exposure of mice to the motility boxes for 3 consecutive days induced a significant inhibition of locomotor activity in the wild-type (+/+) mice compared to homozygous (-/-) animals. The administration of naloxone (10 mg/kg i.p.) to animals, adapted to the motility boxes, induced a significant reduction of locomotor activity in the homozygous (-/-), but not in the wild-type (+/+) mice. Treatment of habituated mice with morphine (10 mg/kg i.p.) caused a stronger increase of locomotor activity in the wild-type (+/+) mice compared to the homozygous (-/-) littermates. In the place preference test the pairing of the preferred side with naloxone (1 and 10 mg/kg i.p.) induced a dose-dependent place aversion in the wild-type (+/+) mice. The treatment with naloxone was less effective in the homozygous (-/-) mice, because the high dose of naloxone (10 mg/kg) tended to shift the preference. The pairing of morphine (3 mg/kg i.p.) injections with the non-preferred side induced a significant place preference both in the wild-type (+/+) and homozygous (-/-) mice. The increased density of opioid receptors was established in the striatum of homozygous (-/-) mice, but not in the other forebrain structures. In conclusion, the targeted invalidation of CCK(2) receptors induces a dissociation of behavioural effects of morphine and naloxone. Morphine-induced place preference remained unchanged, whereas hyper-locomotion was less pronounced in the mutant mice compared to the wild-type (+/+) littermates. By contrast, naloxone-induced place aversion was weaker, but naloxone caused a stronger inhibition of locomotor activity in the homozygous (-/-) mice than in the wild-type (+/+) animals. These behavioural alterations can be explained in the light of data that the targeted mutation of CCK(2) receptors induces distinct changes in the properties of opioid receptors in various brain structures.
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Affiliation(s)
- Kertu Rünkorg
- Department of Physiology, Biomedicum, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
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13
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Raud S, Rünkorg K, Veraksits A, Reimets A, Nelovkov A, Abramov U, Matsui T, Bourin M, Volke V, Kõks S, Vasar E. Targeted mutation of CCK2 receptor gene modifies the behavioural effects of diazepam in female mice. Psychopharmacology (Berl) 2003; 168:417-25. [PMID: 12709779 DOI: 10.1007/s00213-003-1453-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2002] [Accepted: 03/04/2003] [Indexed: 10/26/2022]
Abstract
RATIONALE Evidence suggests that GABA and CCK have opposite roles in the regulation of anxiety. OBJECTIVE The aim of the present work was to study diazepam-induced anxiolytic-like action and impairment of motor co-ordination, and the parameters of benzodiazepine receptors in mice lacking CCK2 receptors. METHODS The action of diazepam (0.5-3 mg/kg i.p.) was studied in the elevated plus-maze model of anxiety and rotarod test using mice lacking CCK2 receptors. The parameters of benzodiazepine receptors were analysed using [3H]-flunitrazepam binding. RESULTS In the plus-maze test, the exploratory activity of the homozygous (-/-) mice was significantly higher compared to their wild-type (+/+) littermates. However, the wild-type (+/+) mice displayed higher sensitivity to the anxiolytic-like action of diazepam. Even the lowest dose of diazepam (0.5 mg/kg) induced a significant increase of open arm entries in the wild-type (+/+) mice. A similar effect in the homozygous (-/-) mice was established after the administration of diazepam 1 mg/kg. The highest dose of diazepam (3 mg/kg) caused a prominent anxiolytic-like effect in the wild-type (+/+) mice, whereas in the homozygous (-/-) animals suppression of locomotor activity was evident. The performance of the homozygous (-/-) mice in the rotarod test did not differ from that of the wild-type (+/+) littermates. However, a difference between the wild-type (+/+) and homozygous (-/-) animals became evident after treatment with diazepam. Diazepam (0.5 and 3 mg/kg) induced significantly stronger impairment of motor co-ordination in the homozygous (-/-) mice compared to their wild-type (+/+) littermates. The density of benzodiazepine binding sites was increased in the cerebellum, but not in the cerebral cortex and hippocampus, of the homozygous (-/-) mice. CONCLUSIONS Female mice lacking CCK2 receptors are less anxious than their wild-type (+/+) littermates. The reduced anxiety in homozygous (-/-) mice probably explains why the administration of a higher dose of diazepam is necessary to induce an anxiolytic-like action in these animals. The highest dose of diazepam (3 mg/kg) induced significantly stronger suppression of locomotor activity and impairment of motor co-ordination in the homozygous (-/-) mice compared to the wild-type (+/+) littermates. The increase in the action of diazepam is probably related to the elevated density of benzodiazepine receptors in the cerebellum of homozygous (-/-) mice. The present study seems to be in favour of increased tone of the GABAergic system in mice without CCK2 receptors.
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Affiliation(s)
- Sirli Raud
- Department of Physiology, Biomedicum, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia
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14
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Hebb ALO, Zacharko RM. Central D-Ala2-Met5-enkephalinamide mu/delta-opioid receptor activation blocks behavioral sensitization to cholecystokinin in CD-1 mice. Brain Res 2003; 970:20-34. [PMID: 12706245 DOI: 10.1016/s0006-8993(02)04221-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The present investigation revealed that intraventricular administration of the anxiogenic substance CCK-8S (50 ng) decreased responding for previously rewarding brain stimulation (intracranial self-stimulation; ICSS) and subsequently increased brain stimulation threshold determinations from the dorsal aspects of the ventral tegmental area (VTA) immediately following CCK administration. While central administration of the mixed mu/delta opioid receptor agonist D-Ala(2)-Met(5)-enkephalinamide (DALA; 1 microg) was ineffective in abrogating CCK induced ICSS deficits during the immediate post-stressor interval, DALA restored ICSS brain stimulation thresholds to basal values 24, 48 and 168 h following CCK challenge. At 18 days following the initial 50 ng CCK-8S and/or DALA challenges, mice were exposed to a previously determined non-anxiogenic dose of CCK-8S (5 ng). Among mice which received an intervening dose of saline following the 50 ng CCK-8S challenge, depressed ICSS responding and elevated brain stimulation thresholds were evident during the immediate (Day 18), 24- (Day 19) and 48-h (Day 20) test sessions relative to mice that received an intervening dose of DALA on Day 1. These data imply that while CCK induces relatively protracted and exaggerated behavioral disturbances, mu/delta opioid-receptor activation may block CCK-induced behavioral sensitization and change the course of psychopathology.
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MESH Headings
- Animals
- Cholecystokinin/pharmacology
- Enkephalin, Methionine/analogs & derivatives
- Enkephalin, Methionine/pharmacology
- Male
- Mice
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Self Stimulation/drug effects
- Self Stimulation/physiology
- Sincalide/analogs & derivatives
- Sincalide/pharmacology
- Ventral Tegmental Area/drug effects
- Ventral Tegmental Area/physiology
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Affiliation(s)
- Andrea L O Hebb
- Institute of Neuroscience, Carleton University, Ottawa, Ont, Canada.
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15
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Veraksits A, Rünkorg K, Kurrikoff K, Raud S, Abramov U, Matsui T, Bourin M, Kõks S, Vasar E. Altered pain sensitivity and morphine-induced anti-nociception in mice lacking CCK2 receptors. Psychopharmacology (Berl) 2003; 166:168-75. [PMID: 12545332 DOI: 10.1007/s00213-002-1333-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2002] [Accepted: 10/18/2002] [Indexed: 11/30/2022]
Abstract
RATIONALE Cholecystokinin (CCK) interacts with the endopioid system in the regulation of various physiological functions, including the control of pain sensitivity, motor activity and emotional behaviour. OBJECTIVE The aim of the present work was to study the pain sensitivity, morphine-induced antinociception and density of opioid receptors in mice lacking CCK(2) receptors. METHODS Plantar analgesia and hotplate tests were used to evaluate pain sensitivity and morphine-induced antinociception. The parameters of opioid receptors were analysed by using [(3)H]-diprenorphine binding. RESULTS In the plantar analgesia test the latency of hind paw withdrawal was significantly increased in CCK(2) receptor deficient mice compared to wild-type (+/+) littermates. The treatment with saline reversed the reduced pain sensitivity in heterozygous (+/-) and homozygous (-/-) mice. The administration of morphine (1 mg/kg) induced a significantly stronger antinociceptive effect in homozygous (-/-) mice compared with wild-type (+/+) animals. In the hotplate test, only homozygous (-/-) mutant mice displayed the delayed latency of hind paw licking/shaking in comparison with wild-type (+/+) mice. The injection of saline and isolation of mice for 30 min reversed the delayed response in homozygous (-/-) mice. However, in this test, the anti-nociceptive action of morphine (5-10 mg/kg) in mutant mice did not differ from that in wild-type (+/+) littermates. By contrast, the jump latency was decreased in both homozygous (-/-) and heterozygous (+/-) mice in the hotplate test. The increased density of opioid receptors was established in the striatum of homozygous (-/-) mice. CONCLUSION It is apparent that the targeted mutagenesis of the CCK(2) receptor gene has different effects on the sensitivity of opioid receptors in various brain structures. This is a probable reason for the altered pain sensitivity and morphine-induced antinociception in mutant mice compared to wild-type (+/+) littermates.
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Affiliation(s)
- Alar Veraksits
- Department of Physiology, Biomedicum, University of Tartu, 19 Ravila Street, 50411, Tartu, Estonia
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16
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Abstract
This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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17
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Abstract
Cholecystokinin (CCK) is a peptide originally discovered in the gastrointestinal tract, but also found in high density in the mammalian brain. This peptide has been shown to be involved in numerous physiological functions such as feeding behavior, central respiratory control and cardiovascular tonus, vigilance states, memory processes, nociception, emotional and motivational responses. CCK interacts with nanomolar affinites with two different receptors designated CCK(1) and CCK(2). Primarily, the functional role of these binding sites in the brain and the periphery has been investigated thanks to the development of potent and selective CCK receptor antagonists and agonists. However, several studies have yielded conflicting data. Knockout mice provide unique opportunities to analyse diverse aspects of gene function in vivo. This review highlights recent progress in our understanding of the role of CCK(1) and CCK(2) receptors obtained by using mice with genetic invalidation of CCK(1) or CCK(2) receptors or natural CCK receptors mutants. The limits of this approach is discussed and some results were compared to those obtained by pharmacological blockade of CCK receptors by selective antagonists.
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Affiliation(s)
- F Noble
- Département de Pharmacochimie Moléculaire et Structurale, INSERM U266 - CNRS UMR8600, UFR des Sciences Pharmaceutiques et Biologiques, 4, Avenue de l'Observatoire 75270, Paris Cedex 06, France
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