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| 2. |
- Annerbrink, Kristina, 1974, et al.
(författare)
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Serotonin depletion increases respiratory variability in freely moving rats: implications for panic disorder.
- 2003
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Ingår i: The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP). - 1469-5111. ; 6:1, s. 51-6
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Tidskriftsartikel (refereegranskat)abstract
- To elucidate if serotonergic transmission affects respiratory variability, a parameter consistently found increased in patients with panic disorder, we studied the effect of a serotonin synthesis inhibitor, para-chlorophenylalanine (PCPA), on respiratory variability at baseline and during CO2-induced hyperventilation in awake and unrestrained rats. Forty male Wistar rats were given intraperitoneal injections of PCPA (300 mg/kg) or saline 72, 48 and 24 h before registration of respiration in a plethysmograph allowing the animals to move freely. PCPA-treated rats displayed significantly higher tidal volume variability and minute volume variability, both at baseline and during CO2 exposure, compared to controls. The results support the notion that serotonin dysfunction may contribute to the enhanced respiratory variability observed in patients with panic disorder.
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| 3. |
- de Frias, Cindy M, et al.
(författare)
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COMT gene polymorphism is associated with declarative memory in adulthood and old age.
- 2004
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Ingår i: Behavior genetics. - New York : Kluwer Academic Publishers. - 0001-8244 .- 1573-3297. ; 34:5, s. 533-9
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Tidskriftsartikel (refereegranskat)abstract
- Variation in memory performance is to a large extent explained by genes. In the prefrontal cortex, the catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine, a neurotransmitter implicated in cognitive functions. The present study examined the effect of a polymorphism in the COMT gene on individual differences and changes in memory in adulthood and old age. Tests assessing episodic and semantic memory were administered to 286 men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula prospective cohort study) at two occasions followed over a 5-year period. Carriers of the Met/Met genotype (with low enzyme activity) performed better on episodic and semantic memory, as compared to carriers of the Val allele (with higher enzyme activity). Division of episodic memory into its recall and recognition components showed that the difference was specific to episodic recall, not recognition tasks; an effect that was observed across three age groups (middle-age, young-old, and old-old adults) and over a 5-year period. The COMT gene is a plausible candidate gene for memory functioning in adulthood and old age.
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| 4. |
- Ho, Hoi-Por, 1962, et al.
(författare)
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Association between a functional polymorphism in the progesterone receptor gene and panic disorder in women.
- 2004
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530. ; 58:2, s. 109-110
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Tidskriftsartikel (refereegranskat)abstract
- Although genetic factors are known to be important risk factors for panic disorder there is as yet no conclusive data regarding specific gene variants. Prompted by evidence supporting progesterone to influence the pathophysiology of panic disorder, polymorphisms in the progesterone receptor gene, a single nucleotide polymorphism (G331A) and an insertion/deletion polymorphism (PROGINS) were investigated in 72 patients with panic disorder and 452 controls. The frequency of the A-allele of the G331A polymorphism was higher in panic disorder patients than in controls (p = 0.01). When male and female patients were analyzed separately, the association was observed in female patients only (p = 0.0009), with an odds ratio of 3.5. No differences between groups were observed for the PROGINS polymorphism. In conclusion, these data suggest that the G331A polymorphism in the progesterone receptor gene may influence the risk for panic disorder in women.
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| 5. |
- Melchior, Lydia K, 1979, et al.
(författare)
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Association between estrus cycle-related aggression and tidal volume variability in female Wistar rats.
- 2004
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530. ; 29:8, s. 1097-100
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Tidskriftsartikel (refereegranskat)abstract
- Premenstrual dysphoria is characterized by symptoms such as irritability and depressed mood, present during the luteal phase of the menstrual cycle, and disappearing shortly after the onset of menstruation. Subjects with premenstrual dysphoria have previously been reported to display enhanced respiratory variability, and to experience anxiety when exposed to panicogens, such as CO2. In the present study, the possible influence of the estrus cycle and estrus cycle-related aggression on respiratory variability was investigated in female rats of the Wistar strain. The rats were subdivided into two groups: those displaying estrus cycle-related aggression, as evaluated using the resident intruder paradigm, and those not showing aggression throughout the estrus cycle. This model has been developed to serve as an animal model of premenstrual irritability. The former group was found to display higher tidal volume variability in diestrus, as compared to the non-aggressive rats. There was no effect of estrus cycle phase on respiratory variability. These results are well in line with the clinical observation that women with premenstrual dysphoria display higher respiratory variability than controls, and the notion that respiratory variability is a parameter of interest in this context. In our opinion, they also strengthen the concept of this animal model as a model of premenstrual irritability.
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| 6. |
- Olsson, Marie, 1971, et al.
(författare)
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Angiotensin-related genes in patients with panic disorder.
- 2004
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Ingår i: American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics. - : Wiley. - 1552-4841. ; 127:1, s. 81-4
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Tidskriftsartikel (refereegranskat)abstract
- Enhanced respiratory variability and decreased heart rate variability have repeatedly been observed in patients with panic disorder. Prompted by the notion that angiotensin may be involved in the control of respiration, heart rate variability, and anxiety-like behavior, we investigated the putative association between polymorphisms in three angiotensin-related genes and panic disorder-angiotensinogen (AGT), angiotensin converting enzyme (ACE), and angiotensin II (ANG II) receptor type 1 (ATr1) in 72 patients with panic disorder and 504 controls. Allele and genotype distribution of the ATr1 A1166C allele and the AGT M235T did not differ between patients and controls. With respect to the ACE I/D polymorphism, the I allele was found to be more frequent in male (chi(2) = 8.042, df = 1, P = 0.005), but not female, panic disorder patients than in controls. The results of this investigation provide preliminary evidence for the suggestion that angiotensin-related genes may be associated with panic disorder in men.
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| 7. |
- Olsson, Marie, 1971, et al.
(författare)
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Association between estrus cycle-related changes in respiration and estrus cycle-related aggression in outbred female Wistar rats.
- 2003
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Ingår i: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology. - : Springer Science and Business Media LLC. - 0893-133X. ; 28:4, s. 704-10
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Tidskriftsartikel (refereegranskat)abstract
- Premenstrual dysphoric disorder is characterized by irritability surfacing during the luteal phase of the menstrual cycle, and disappearing shortly after the onset of menstruation. Although the cardinal symptoms of premenstrual dysphoria are different from those of panic disorder, the two conditions share a number of traits indicating that they both may be associated with abnormalities in the regulation of respiration. Both subjects with panic disorder and subjects with premenstrual dysphoria are hence reported to display enhanced respiratory variability, and to experience anxiety when exposed to CO(2). In the present study, the possible influence of the estrus cycle on respiratory parameters in outbred female rats of the Wistar strain was investigated. Before being tested with respect to respiration, the rats were subdivided into two groups: those displaying estrus cycle-related variation in aggression, as evaluated using the resident intruder paradigm, and those not showing aggression throughout the cycle. Whereas the former group was found to display higher respiratory rate during the diestrus phase than during the proestrus/estrus phase, no cycle-related variation in respiration was observed in animals not showing cycle-related variation in aggression. The results support previous studies indicating that the estrus cycle exerts an influence on respiration, and suggest that rats prone to cycle-related aggression are more sensitive also to the influence of hormonal cyclicity on respiration. The possible bearing of these findings for the aberration in respiration displayed by subjects with premenstrual dysphoria is discussed.
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| 8. |
- Olsson, Marie, 1971, et al.
(författare)
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Intracerebroventricular administration of the angiotensin II receptor antagonist saralasin reduces respiratory rate and tidal volume variability in freely moving Wistar rats.
- 2004
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Ingår i: Psychoneuroendocrinology. - 0306-4530. ; 29:1, s. 107-12
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Tidskriftsartikel (refereegranskat)abstract
- The possible importance of intra-individual variations in respiratory rate and tidal volume has recently gained interest in psychiatric research, as a result of the observations that patients with panic disorder or premenstrual dysphoric disorder display enhanced respiratory variability as compared to controls. Although the role of brain neurotransmitters in the regulation of breathing has been extensively studied, as yet data on the central regulation of respiratory variability is sparse. Prompted by previous studies indicating that angiotensin II (ANG II) may influence ventilation as well as anxiety, we have studied the effect of intracerebroventricular administration of an ANG II receptor antagonist, saralasin, on respiratory variability in unrestrained, freely moving male Wistar rats. Treatment with saralasin, 5 mug dissolved in 1 mul saline followed by 9 mul saline in each lateral cerebral ventricle, did not influence tidal volume, but markedly reduced tidal volume variability (p=0.0005), as compared to saline injections (10 mul). Respiratory rate was reduced by saralasin (p=0.02), and there was also a non-significant tendency for a reduction in respiratory rate variability. Both minute volume (p=0.005) and volume/10 s variability (p=0.0006) were reduced. It is suggested that ANG II in the brain of Wistar rats may regulate respiratory rate and tidal volume variability.
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| 9. |
- Olsson, Marie, 1971, et al.
(författare)
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Paroxetine influences respiration in rats: implications for the treatment of panic disorder.
- 2004
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Ingår i: European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. - 0924-977X .- 1873-7862. ; 14:1, s. 29-37
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Tidskriftsartikel (refereegranskat)abstract
- Since hyperventilation and shortness of breath are characteristic features of panic attacks, and since the attacks can be elicited by CO(2) inhalation, an involvement of central or peripheral chemoreceptors in the pathophysiology of panic disorder has been suggested. Prompted by clinical reports suggesting that the susceptibility to spontaneous as well as CO(2)-induced anxiety and hyperventilation is attenuated by serotonin reuptake inhibitors (SRIs), we undertook the present study in order to explore the possible effect of an SRI, paroxetine, on baseline respiration and CO(2)-induced hyperventilation in freely moving Wistar rats. A significant increase in baseline respiratory rate was seen both after 5 and 15 weeks of treatment with paroxetine. CO(2) exposure induced a dose-dependent increase in respiratory rate, but not tidal volume, in both paroxetine-treated rats and controls; this response was reduced after 15 weeks of paroxetine treatment, but not after 5 weeks of treatment. We suggest that an influence on the regulation of respiration may be of importance for the anti-panic effect of SRIs.
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| 10. |
- Olsson, Marie, 1971, et al.
(författare)
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Respiratory responses to intravenous infusion of sodium lactate in male and female Wistar rats.
- 2002
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Ingår i: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology. - 0893-133X. ; 27:1, s. 85-91
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Tidskriftsartikel (refereegranskat)abstract
- In patients with panic disorder or premenstrual dysphoria, anxiety attacks can be triggered by intravenous administration of sodium lactate. Since respiratory symptoms, such as hyperventilation and shortness of breath, are characteristic features of spontaneous as well as lactate-induced panic, an involvement of central or peripheral chemoreceptors in this reaction has been suggested. In the present study, we examined to what extent intravenous infusion of sodium lactate influences respiratory parameters in freely moving male and female Wistar rats. Prompted by clinical reports suggesting that the susceptibility to spontaneous and lactate-induced anxiety may be influenced by the menstrual cycle, we also investigated if the effect of lactate on respiration in female rats is estrus cycle-dependent. Male and ovariectomized female rats exposed to sodium lactate displayed a larger increase in respiratory rate than rats given an infusion of saline. In intact female rats, the response to lactate infusion was significantly more pronounced in the diestrus phase than in the proestrus/estrus phase of the cycle. It is concluded that sodium lactate is a respiratory stimulant in rat, and that this effect is influenced by female sex steroids.
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