Repeated treatment with imipramine, fluvoxamine and tranylcypromine decreases the number of escape failures by activating dopaminergic systems in a rat learned helplessness test

Takamori, Kazuaki; Yoshida, Seiichiro; Okuyama, Shigeru

doi:10.1016/s0024-3205(01)01279-6

Cited by 42 publications

(22 citation statements)

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“…For example, selective D1 agonists have antidepressant effects in both LH and the FST, while blockade of D1 receptors prevents the antidepressant effect of imipramine as well as other agents (D'Aquila et al, 1994;Gambarana et al, 1995a,b;Takamori et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Strain differences in the expression of dopamine D1 receptors in Wistar–Kyoto (WKY) and Wistar rats

2008

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The Wistar-Kyoto (WKY) rat is a stress-sensitive strain that is prone to depressive-like behavior in various experimental paradigms. While recent work has highlighted a role for dopamine (DA) in the pathology of depression, research on the WKY rat has also suggested that dysfunction of DA pathways may be an important component of the behavior in this strain. Previous work has demonstrated differential patterns of DA transporter sites, DA D2 and D3 receptors in WKY rats compared to control strains. To further this work, the present study utilized autoradiographic analysis of [3H]-SCH23390 binding to DA D1 receptors in various brain regions of naïve male WKY and Wistar (WIS) rats. The results revealed a significant strain difference, with WKY rats demonstrating lower D1 binding in the caudate putamen and regions of the nucleus accumbens (p<0.05). An opposite pattern was found in the substantia nigra pars reticulata where D1 binding was higher in WKY rats compared to WIS rats (p<0.05). Because the D1 receptor represents a critical site where DA acts to modify behavior related to depression, the altered expression of this receptor in the WKY rat found in the present study may be reflective of the depressive susceptibility noted in this strain.

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Section: Introductionmentioning

confidence: 99%

Strain differences in the expression of dopamine D1 receptors in Wistar–Kyoto (WKY) and Wistar rats

2008

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“…With regard to possible involvement of blockade of SET in the pharmacological actions of MCL0129, fluvoxamine, a SSRI, did not show effects on swim stressinduced anxiogenic-like behavior in rats or mice and did not show anxiolytic-like activity in the light/dark exploration test in naive mice (unpublished data). Moreover, fluvoxamine did not have antidepressant activity in the learned helplessness test in the case of an acute administration, whereas it was effective in repeated administration in the present experimental condition (Takamori et al, 2001b). These results clearly show that the effects of MCL0129 are mediated through the MC4 receptor, although involvement of the 1 receptor needs to be ruled out.…”

Section: Discussionmentioning

confidence: 41%

Anxiolytic-Like and Antidepressant-Like Activities of MCL0129 (1-[(S)-2-(4-Fluorophenyl)-2-(4-isopropylpiperadin-1-yl)ethyl]-4-[4-(2-methoxynaphthalen-1-yl)butyl]piperazine), a Novel and Potent Nonpeptide Antagonist of the Melanocortin-4 Receptor

Chaki¹,

Hirota²,

Funakoshi³

et al. 2003

J Pharmacol Exp Ther

106

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ABSTRACT]-␣-melanocyte-stimulating hormone (␣-MSH) binding to MC4 receptor with a K i value of 7.9 nM, without showing affinity for MC1 and MC3 receptors. MCL0129 at 1 M had no apparent affinity for other receptors, transporters, and ion channels related to anxiety and depression except for a moderate affinity for the 1 receptor, serotonin transporter, and ␣ 1 -adrenoceptor, which means that MCL0129 is selective for the MC4 receptor. MCL0129 attenuated the ␣-MSHincreased cAMP formation in COS-1 cells expressing the MC4 receptor, whereas MCL0129 did not affect basal cAMP levels, thereby indicating that MCL0129 acts as an antagonist at the MC4 receptor. Swim stress markedly induced anxiogenic-like effects in both the light/dark exploration task in mice and the elevated plus-maze task in rats, and MCL0129 reversed the stress-induced anxiogenic-like effects. Under nonstress conditions, MCL0129 prolonged time spent in the light area in the light/dark exploration task and suppressed marble-burying behavior. MCL0129 shortened immobility time in the forced swim test and reduced the number of escape failures in inescapable shocks in the learned helplessness test, thus indicating an antidepressant potential. In contrast, MCL0129 had negligible effects on spontaneous locomotor activity, Rotarod performance, and hexobarbital-induced anesthesia. These observations indicate that MCL0129 is a potent and selective MC4 antagonist with anxiolytic-and antidepressantlike activities in various rodent models. MC4 receptor antagonists may prove effective for treating subjects with stress-related disorders such as depression and/or anxiety.Stress initiates a complex cascade of responses that include endocrine, biochemical, and behavioral events. Many of these responses are initiated by release of corticotropin-releasing factor (CRF) (Owen and Nemeroff, 1991). In addition to activation of the brain CRF system, there are several lines of evidence that melanocortins (MCs), which stem from proopiomelanocortin by enzymatic processing, mediate important behavioral and biochemical responses to stress and, consequently, stress-induced disorders. Among MCs, it was reported that ␣-melanocyte-stimulating hormone (␣-MSH) acts as a neurotransmitter or neuromodulator in the brain (Blasquez et al., 1991), and the relationship between ␣-MSH and adrenocorticotropic hormone (ACTH) and stress has been well documented. ␣-MSH and ACTH induce excessive grooming behavior in rats, a rodent behavioral response to stressful situations (De Barioglio et al., 1991;Adan et al., 1999), and antiserum to ACTH reduces novelty-induced grooming (Dunn et al., 1979). ␣-MSH and ACTH have been shown to inhibit the punish response in the Vogel conflict test in rats (Corda et al., 1990), and microinjection of ␣-MSH into the medial preoptic area and ventromedial nucleus increases anxiety and aggressive behavior (Gonzalez et al., 1996). Moreover, ACTH inhibits social contacts in the social interaction test in rats, an effect indicative of anxiogenic properties (File and Clarke, ...

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“…Instead, the learned helplessness procedure has been widely used for the screening of antidepressant drugs (for a review, see Maier 1984;Willner 1984;Vollmayr and Henn 2001;Cryan et al 2002). Notably, a critical role of central dopamine in the control and modulation of inescapable shock-induced escape deficits in the learned helplessness paradigm has been identified (Muscat et al 1992;Besson et al 1998Besson et al , 1999Takamori et al 2001;Kram et al 2002;Millan et al 2004). Specifically, it has been demonstrated that the reversal of shock-induced deficits in avoidance and/or escape learning is associated with an increase in the functional responsiveness of central dopaminergic systems (Besson et al 1998;Takamori et al 2001).…”

Section: Learned Helplessnessmentioning

confidence: 99%

“…Notably, a critical role of central dopamine in the control and modulation of inescapable shock-induced escape deficits in the learned helplessness paradigm has been identified (Muscat et al 1992;Besson et al 1998Besson et al , 1999Takamori et al 2001;Kram et al 2002;Millan et al 2004). Specifically, it has been demonstrated that the reversal of shock-induced deficits in avoidance and/or escape learning is associated with an increase in the functional responsiveness of central dopaminergic systems (Besson et al 1998;Takamori et al 2001). This agrees with the observation that dopamine function is enhanced after chronic antidepressant treatment (see Willner 1983).…”

Section: Learned Helplessnessmentioning

confidence: 99%

Disruption of the US pre-exposure effect and latent inhibition in two-way active avoidance by systemic amphetamine in C57BL/6 mice

et al. 2006

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Rationale Pre-exposure to either one of the two to-beassociated stimuli alone is known to reduce the efficiency of the learning of their association when they are subsequently paired explicitly. In classical conditioning, pre-exposure to the conditioned stimulus (CS) gives rise to latent inhibition (LI); and pre-exposure to the unconditioned stimulus (US) results in the US pre-exposure effect (USPEE). Considerable evidence supports an important role of central dopamine in the regulation and modulation of LI; it has been suggested that the USPEE may be similarly controlled by dopamine, but this parallelism has only been directly demonstrated in the conditioned taste aversion paradigm. Objective The present study tested this hypothesis by comparing the efficacy of systemic amphetamine treatment to affect the expression of LI and the USPEE in a two-way active avoidance paradigm. Methods C57BL/6 male mice were tested in active avoidance using a tone CS and a foot-shock US. Twenty-four hours before, they were pre-exposed to 100 presentations of the CS or the US, or to the test apparatus only. Amphetamine (2.5 mg/kg) or saline was administered before stimulus preexposure and conditioned avoidance test, in which the mice learned to avoid the shock by shuttling in response to the tone. Results Amphetamine disrupted both stimulus pre-exposure effects, thus, lending further support to the hypothesis that the USPEE is similar to LI in its sensitivity to dopamine receptor agonist. Hence, the USPEE paradigm may represent a valuable addition to the study of dopamine-sensitive processes of selective learning currently implicated in LI and Kamin blocking.

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Repeated treatment with imipramine, fluvoxamine and tranylcypromine decreases the number of escape failures by activating dopaminergic systems in a rat learned helplessness test

Cited by 42 publications

References 0 publications

Strain differences in the expression of dopamine D1 receptors in Wistar–Kyoto (WKY) and Wistar rats

Strain differences in the expression of dopamine D1 receptors in Wistar–Kyoto (WKY) and Wistar rats

Anxiolytic-Like and Antidepressant-Like Activities of MCL0129 (1-[(S)-2-(4-Fluorophenyl)-2-(4-isopropylpiperadin-1-yl)ethyl]-4-[4-(2-methoxynaphthalen-1-yl)butyl]piperazine), a Novel and Potent Nonpeptide Antagonist of the Melanocortin-4 Receptor

Disruption of the US pre-exposure effect and latent inhibition in two-way active avoidance by systemic amphetamine in C57BL/6 mice

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