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Larry S. Zweifel - One of the best experts on this subject based on the ideXlab platform.
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Divergent medial amygdala projections regulate approach–avoidance Conflict Behavior
Nature Neuroscience, 2019Co-Authors: Samara M Miller, Daniele Marcotulli, Angela Shen, Larry S. ZweifelAbstract:Avoidance of innate threats is often in Conflict with motivations to engage in exploratory approach Behavior. The neural pathways that mediate this approach–avoidance Conflict are not well resolved. Here we isolated a population of dopamine D1 receptor (D1R)-expressing neurons within the posteroventral region of the medial amygdala (MeApv) in mice that are activated either during approach or during avoidance of an innate threat stimulus. Distinct subpopulations of MeApv-D1R neurons differentially innervate the ventromedial hypothalamus and bed nucleus of the stria terminalis, and these projections have opposing effects on investigation or avoidance of threatening stimuli. These projections are potently modulated through opposite actions of D1R signaling that bias approach Behavior. These data demonstrate divergent pathways in the MeApv that can be differentially weighted toward exploration or evasion of threats. Miller et al. show that subpopulations of D1 receptor-expressing neurons in the medial amygdala modulate approach–avoidance responses to threats through inhibitory and excitatory projections to the extended amygdala and hypothalamus, respectively.
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Divergent medial amygdala projections regulate approach-avoidance Conflict Behavior.
Nature neuroscience, 2019Co-Authors: Samara M Miller, Daniele Marcotulli, Angela Shen, Larry S. ZweifelAbstract:Avoidance of innate threats is often in Conflict with motivations to engage in exploratory approach Behavior. The neural pathways that mediate this approach-avoidance Conflict are not well resolved. Here we isolated a population of dopamine D1 receptor (D1R)-expressing neurons within the posteroventral region of the medial amygdala (MeApv) in mice that are activated either during approach or during avoidance of an innate threat stimulus. Distinct subpopulations of MeApv-D1R neurons differentially innervate the ventromedial hypothalamus and bed nucleus of the stria terminalis, and these projections have opposing effects on investigation or avoidance of threatening stimuli. These projections are potently modulated through opposite actions of D1R signaling that bias approach Behavior. These data demonstrate divergent pathways in the MeApv that can be differentially weighted toward exploration or evasion of threats.
Randall L. Commissaris - One of the best experts on this subject based on the ideXlab platform.
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The effects of selective and non-selective monoamine oxidase (MAO) inhibitors on Conflict Behavior in the rat.
Behavioural pharmacology, 1995Co-Authors: Randall L. Commissaris, J. Humrich, J. Johns, D. G. Geere, D. J. FontanaAbstract:Conflict Behavior in rats was examined over the course of several weeks of chronic treatment with selective and non-selective monoamine oxidase inhibitors (MAOIs). In daily 10min sessions, rats were trained to drink from a tube which was occasionally electrified (0.5mA). Electrification was signalled by the presence of a tone. Within 3-4 weeks, control (i.e. non-drug) Conflict Behavior had stabilized (30-40 shocks and 8-12ml water/session) and drug testing began. Chronic administration (two injections/day for 8 weeks) with a non-selective (i.e. MAO-A and MAO-B inhibiting) dose of pargyline (15mg/kg) resulted in a time-dependent increase in punished responding. In contrast, chronic administration of the MAO-A selective inhibitor (clorgyline; 1.0mg/kg, 2mg/kg), the MAO-B selective inhibitor deprenyl (5mg/kg) or MAO-B inhibiting doses of pargyline (1.0mg/kg, 5mg/kg) were without effect. Finally, chronic treatment with the combination of a low dose of clorgyline (1.0mg/kg) and a low dose of pargyline (1.0mg/kg) did result in a time-dependent increase in punished responding. These results suggest that inhibition of both MAO-A and MAO-B is required for the eventuation of the anxiolytic effect resulting from chronic MAOI treatment.
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High‐dose subchronic imipramine treatment: Effects on anxiety‐like (Conflict) Behavior in rats
Anxiety, 1994Co-Authors: Randall L. Commissaris, Timothy J. HillAbstract:In the management of both anxiety and depression, agents such as imipramine (IMI) are noted for their 3–5 week delay to onset of clinical effect. A similar delay to onset has been reported for the anxiolytic-like (i.e., antiConflict) effect of chronic IMI treatment (2.5 mg/kg, BID for 5 weeks) in the Conditioned Suppression of Drinking (CSD) Conflict paradigm; similar effects have been reported with other antidepressants and in other Conflict procedures. In contrast, in the Forced Swim Test (FST) model of depression, antidepressant-like effects are reported immediately following subchronic treatment with relatively high doses of these agents (e.g., 30 mg/kg IMI, 3 times in 24 hr). The present study examined the effects of this high-dose, subchronic treatment with IMI on CSD Conflict Behavior. Conflict-trained female Sprague Dawley rats were divided into three groups with comparable pretreatment baselines for shocks received. Treatments (0, 15, and 30 mg/kg IMI) were administered intraperitoneally (IP) at 23, 5, and 1 hr prior to CSD Conflict testing on day 1; CSD Conflict Behavior was then monitored daily (Mon-Fri) for 5 weeks following treatment. IMI treatment (30 and, to a lesser extent, 15 mg/kg) significantly reduced shocks received (punished responding) and water intake (unpunished responding) on day 1; although water intake was also slightly reduced in both IMI treatment groups for the remainder of test week 1, there was no difference in shocks received between the various treatments for this period. Subjects receiving 30 mg/kg IMI (but not those receiving 15 mg/kg IMI or vehicle) accepted significantly more shocks than controls on weeks 2–4 (maximal increase at week 3) and returned to pretreatment baseline levels by week 5. Thus, subchronic high-dose treatment with IMI (and perhaps other antidepressants) produces anxiolytic-like effects which are delayed in nature and persist for several weeks after treatment. Anxiety 1:109–113 (1994/1995). © 1995 Wiley-Liss, Inc.
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Conflict Behavior in Maudsley reactive and nonreactive rats: effects of noradrenergic neuronal destruction.
Pharmacology biochemistry and behavior, 1993Co-Authors: J.s. Verbanac, Harvey J. Altman, P. Dhingra, Gordon M. Harrington, Randall L. CommissarisAbstract:Abstract The present studies were designed to examine the effects of treatment with the noradrenergic neurotoxin N -(2-chloroethyl)- n -ethyl-2-bromobenzylamine HCl (DSP4; 65 mg/kg, IP) on Conflict Behavior in the Maudsley reactive (MR) and nonreactive (MNRA) rat strains. In daily 10-min sessions, water-restricted rats were trained to drink water from a tube that was ocassionally electrified; electrification was signaled by the presence of a tone (7-s duration; ISI = 30 s). Consistent with previous reports, the number of shocks accepted by rats of the MR and MNRA strains did not differ initially, but MNRA rats exhibited a dramatic increase in punished responding relative to their MR counterparts over the course of several weeks of Conflict testing. This MR vs. MNRA strain difference in punished responding did not exhibit extinction following discontinuation of CSD Conflict Behavior testing for a period of 6 weeks. Whether it was administered after Conflict training or before, DSP4 treatment did not reduce the MR vs. MNRA strain difference in Conflict Behavior; rather, DSP4 treatment tended to increase the magnitude of the MR vs. MNRA difference in Conflict Behavior. The effects of DSP4 on norepinephrine (NE) and 5-hydroxytrypamine (5-HT) concentrations in the pons medulla region were determined in one group of Conflict-experienced MR and MNRA rats (35 weeks after administration) and in a second group of naive MR and MNRA rats (3 weeks after administration). There were no MR vs. MNRA strain differences in NE or 5-HT concentrations in vehicle-treated rats. DSP4 treatment significantly reduced NE, but not 5-HT, concentrations when compared to control values; rats that were sacrificed 3 weeks following DSP4 administration exhibited a greater NE depletion than did rats sacrificed 35 weeks after DSP4 administration. Finally, there were no significant correlations between pons medulla region NE concentrations and Conflict Behavior in either strain alone or when the data from the two strains were combined. The present results are not consistent with the hypothesis that the MR vs. MNRA strain difference in Conflict Behavior is the result of strain differences in brain NE function.
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β-carboline and pentylenetetrazol effects on Conflict Behavior in the rat
Pharmacology biochemistry and behavior, 1992Co-Authors: Timothy J. Hill, David J. Fontana, Timothy C. Mccloskey, Randall L. CommissarisAbstract:The beta-carbolines and the convulsant agent pentylenetetrazol (PTZ) have been reported as "anxiogenic" in several animal models for anxiety. The present study examined the effects of the beta-carboline noreleagnine (NOR) and PTZ, administered alone and in combination with the benzodiazepine antagonist, Ro 15-1788, on Behavior in the conditioned suppression of drinking (CSD) Conflict procedure. In daily 10-min sessions, water-deprived female SD rats were trained to drink from a tube that was electrified (0.25 mA). Electrification was signaled by a tone. Acute (20-min) treatment with NOR or PTZ resulted in a dose-dependent decrease in both punished responding (shocks received) and unpunished responding (water intake). Both NOR and PTZ decreased punished responding only at doses that also depressed unpunished responding. Coadministration of Ro 15-1788 (2 mg/kg) reduced the effects of NOR on punished, but not unpunished, responding; this Ro 15-1788 cotreatment reduced the effects of PTZ on both punished and unpunished responding. These data suggest that both PTZ and NOR produce benzodiazepine receptor-mediated anxiogenic-like effects on Conflict Behavior.
Miguel Molina-hernández - One of the best experts on this subject based on the ideXlab platform.
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Female Wistar rats tested during late proestrus or during pregnancy and ovariectomized rats tested after receiving progesterone or allopregnanolone displayed reduced Conflict Behavior.
Progress in neuro-psychopharmacology & biological psychiatry, 2002Co-Authors: Miguel Molina-hernández, Julian Perez Garcia, Jorge Ivan Olivera LopezAbstract:In a Conflict test based on the rat's choice between an immediate punished reinforcer or a delayed nonpunished reinforcer, anxiolytic drugs increase the number of immediate punished reinforcers. In this study, two hypotheses were tested: first, during late proestrus or during midpregnancy, female rats will display an elevated amount of immediate punished reinforcers; second, ovariectomized rats will display an elevated amount of immediate punished reinforcers when they receive anxiolytic doses of neurosteroids. Thus, female rats (n = 15) were tested repeatedly during late proestrus, diestrus, and pregnancy in the aforementioned Conflict task. They displayed an elevated amount of immediate punished reinforcers during late proestrus (P < .05) and during the 14th (P < .05) and 17th (P < .05) days of pregnancy compared to diestrus or 3rd, 7th, or 20th days of pregnancy. Likewise, ovariectomized rats (n = 90) displayed an elevated amount of immediate punished reinforcers compared to control rats only when they received anxiolytic doses of progesterone (1.0-2.0 mg/kg, P < .05) or allopregnanolone (1.0-2.0 mg/kg, P < .05). In conclusion, female rats displayed reduced Conflict Behavior during late proestrus and pregnancy, or after received anxiolytic doses of neurosteroids.
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Estrus variation in antiConflict effects of midazolam microinjected into septal nuclei in female Wistar rats.
Pharmacology Biochemistry and Behavior, 2001Co-Authors: Miguel Molina-hernández, N.p. Tellez-alcántaraAbstract:Effects of midazolam intraperitoneally (3.0 mg/kg) administered, or locally applied into lateral septal nuclei (10 μg/μl), or into the medial septum (10 μg/μl) were assessed in Wistar rats during late proestrus or metestrus–diestrus in a Conflict-operant task. A reduction in Conflict Behavior was found in control rats during late proestrus (P
Samara M Miller - One of the best experts on this subject based on the ideXlab platform.
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Divergent medial amygdala projections regulate approach–avoidance Conflict Behavior
Nature Neuroscience, 2019Co-Authors: Samara M Miller, Daniele Marcotulli, Angela Shen, Larry S. ZweifelAbstract:Avoidance of innate threats is often in Conflict with motivations to engage in exploratory approach Behavior. The neural pathways that mediate this approach–avoidance Conflict are not well resolved. Here we isolated a population of dopamine D1 receptor (D1R)-expressing neurons within the posteroventral region of the medial amygdala (MeApv) in mice that are activated either during approach or during avoidance of an innate threat stimulus. Distinct subpopulations of MeApv-D1R neurons differentially innervate the ventromedial hypothalamus and bed nucleus of the stria terminalis, and these projections have opposing effects on investigation or avoidance of threatening stimuli. These projections are potently modulated through opposite actions of D1R signaling that bias approach Behavior. These data demonstrate divergent pathways in the MeApv that can be differentially weighted toward exploration or evasion of threats. Miller et al. show that subpopulations of D1 receptor-expressing neurons in the medial amygdala modulate approach–avoidance responses to threats through inhibitory and excitatory projections to the extended amygdala and hypothalamus, respectively.
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Divergent medial amygdala projections regulate approach-avoidance Conflict Behavior.
Nature neuroscience, 2019Co-Authors: Samara M Miller, Daniele Marcotulli, Angela Shen, Larry S. ZweifelAbstract:Avoidance of innate threats is often in Conflict with motivations to engage in exploratory approach Behavior. The neural pathways that mediate this approach-avoidance Conflict are not well resolved. Here we isolated a population of dopamine D1 receptor (D1R)-expressing neurons within the posteroventral region of the medial amygdala (MeApv) in mice that are activated either during approach or during avoidance of an innate threat stimulus. Distinct subpopulations of MeApv-D1R neurons differentially innervate the ventromedial hypothalamus and bed nucleus of the stria terminalis, and these projections have opposing effects on investigation or avoidance of threatening stimuli. These projections are potently modulated through opposite actions of D1R signaling that bias approach Behavior. These data demonstrate divergent pathways in the MeApv that can be differentially weighted toward exploration or evasion of threats.
N P Tellezalcantara - One of the best experts on this subject based on the ideXlab platform.
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estrus variation in antiConflict effects of midazolam microinjected into septal nuclei in female wistar rats
Pharmacology Biochemistry and Behavior, 2001Co-Authors: Miguel Molinahernandez, N P TellezalcantaraAbstract:Effects of midazolam intraperitoneally (3.0 mg/kg) administered, or locally applied into lateral septal nuclei (10 μg/μl), or into the medial septum (10 μg/μl) were assessed in Wistar rats during late proestrus or metestrus–diestrus in a Conflict-operant task. A reduction in Conflict Behavior was found in control rats during late proestrus (P<.05), when compared to metestrus–diestrus. Systemic injections of midazolam (P<.05) or midazolam infusions into lateral septal nuclei (P<.05) also reduced Conflict Behavior only during late proestrus, whereas midazolam infusions into the medial septum produced neither of these antiConflict effects in any estrous phase. In conclusion, an endocrine-related variation in antiConflict effects of midazolam microinjected into lateral septal nuclei was displayed by female rats.