The effect of two different types of stress on locus coeruleus alpha-2 receptor binding

Weiss, Gerald K.; Ratner, Albert; Voltura, Anna; Savage, Daniel D.; Lucero, Kristen; Castillo, Natalie

doi:10.1016/0361-9230(94)90255-0

Cited by 24 publications

(8 citation statements)

References 21 publications

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“…The striking homogeneity in spontaneous and evoked activity in LC neurons both within and across trials reaffirms what has previously been reported for rats (Sara & Segal, 1991; Valentino et al ., 1991; Weiss et al ., 1994; Vankov et al ., 1995; Shinba et al ., 2000) and primates (Aston‐Jones et al ., 1997, 1999). Virtually all cells showed the same pattern of responses to within‐trial events and the same plasticity of responding with changing stimulus‐reward contingencies across trials.…”

Section: Lc Activitysupporting

confidence: 91%

Reward expectation, orientation of attention and locus coeruleus‐medial frontal cortex interplay during learning

Bouret

Sara

2004

Eur J of Neuroscience

315

269

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Regulation of attention and promotion of behavioural flexibility are functions attributed to both the noradrenergic nucleus locus coeruleus (LC) and the prefrontal cortex (PFC). The PFC receives a large innervation from LC and small changes in catecholaminergic activity in PFC profoundly affect cognitive function. It is crucial to the understanding of learning-related plasticity, that the cognitive context driving LC neurons be determined and the relation to activity in PFC be elucidated. To this end simultaneous recordings were made from LC and prelimbic cortex (PL) during an odour-reward association task in the rat. Neuronal activity related to orientation of attention, reward predictability, reward itself, and changes in stimulus reinforcement contingencies, was measured. All LC neurons and a significant proportion of PL neurons were engaged during several aspects of a Go/NoGo task, especially after the signal for trial onset and CS+ presentation. LC activation was, however, more tightly aligned to the behavioural response than to the CS+ 22% of PL neurons were activated during the response-reward delay. This suggests that the activity of both these structures is related to reward anticipation. Finally, LC neurons exhibited rapid plasticity when the reward-contingency was modified. Within-trial response latencies were always shorter in LC than in PL and between-trial response adaptation in LC preceded that in PL by many trials. Identifying such temporal relationships is an essential step toward understanding how neuromodulatory inputs to forebrain networks might promote or permit experience-dependent plasticity in behavioural situations.

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Section: Lc Activitysupporting

confidence: 91%

Reward expectation, orientation of attention and locus coeruleus‐medial frontal cortex interplay during learning

Bouret

Sara

2004

Eur J of Neuroscience

315

269

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“…However, a decrease in the sensitivity of the presynaptic a 2 -adrenoceptors which modulate the Þring rate in Lc neurons has been reported 24 and 48 h after exposure to a single inescapable electric shock (Pavcovich and Ramirez 1991). Moreover, biochemical studies have described either reductions, increases or even no changes in the a¦nity and / or density of central a 2 -adrenoceptors in brainstem and in some brain regions innervated from Lc, such as amygdala, hippocampus and cerebral cortex, immediately or a few hours after a single exposure to diverse types of stressors (UPrichard and Kvetnansky 1980;Cohen et al 1986;Nukina et al 1987;Weiss et al 1994). The di¤erences described in relation to the modulation of central a 2 -adrenoceptors induced by exposure to a single stressor could be due to the type of stressor applied, the time-lapse since its application, the brain area analyzed, or the in vivo or in vitro techniques used.…”

Section: Discussionmentioning

confidence: 98%

Repeated tail pinch leads to desensitization of postsynaptic α 2 -adrenoceptors which modulate the jaw-opening reflex in the rat

et al. 1998

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There are few in vivo studies which have investigated the modulation of central postsynaptic alpha2-adrenoceptors functionality provoked by stress. We assessed in the rat the effects of either single or repeated tail pinch on clonidine-induced inhibition of the jaw-opening reflex (JOR) via activation of postsynaptic central alpha2-adrenoceptors. At the end of each experimental period, the progressive inhibition of the digastric electromyographic responses elicited by orofacial electrical stimulation after the i.v. administration of cumulative doses (x3.3) of clonidine (0.1-10000 microg/kg) was recorded. Single tail pinch did not significantly modify the ability of the agonist to inhibit the JOR, although there was a tendency to decrease the basal amplitude of the reflex (a 40% reduction) immediately after exposure to the single stressor. However, the dose-response curve for clonidine-induced inhibition of the JOR was clearly shifted to the right in rats exposed to repeated tail pinch (ED50 was increased by 152%, P < 0.0001) when compared with the unstressed control group, without affecting the slope of the inhibitory function and the estimated maximum effect for the agonist. These results show that repeated stress leads to a subsensitivity of the alpha2-adrenoceptors which modulate the JOR, suggesting the development of adaptive mechanisms in postsynaptic alpha2-adrenoceptors in response to stress.

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“…Also, measures of regional cerebral blood flow have indicated a more pronounced response to pain than cold in the pons [31]. Moreover, differences in the stress response have been associated with the duration [31] and intensity [32] of the stressor stimuli. For example, more intense stressors have been associated with the release of larger concentrations of catecholamines [32].…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, differences in the stress response have been associated with the duration [31] and intensity [32] of the stressor stimuli. For example, more intense stressors have been associated with the release of larger concentrations of catecholamines [32]. Nonetheless, the current study found similar changes in cognitive (VAS and SAI) and physiological (heart rate) assessments of arousal in response to the cold pressor test and noxious electrical stimulation, which is consistent with the hypothesis of a non-specific response to stressors [29].…”

Section: Discussionmentioning

confidence: 99%

Comparison of the influence of two stressors on steadiness during index finger abduction

Marmon

Enoka

2010

Physiology & Behavior

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Although several stressors have been used to examine the influence of arousal on motor performance, including noxious electrical stimulation, cold pressor test, and mental math calculations, no study has compared the influence of different physical stressors on motor output. The purpose of the study was to compare the influence of two stressors (cold pressor test and electrical stimulation) on the steadiness of the abduction force exerted by the index finger. Sixteen subjects (22.8 ± 3.5 yrs, 8 women) performed steadiness trials before (anticipatory phase), during (stressor phase), and after (recovery phase) each stressor. The steadiness task involved isometric contractions with the first dorsal interosseus muscle, which is the muscle that produces most of the abduction force exerted by the index finger. Subjects were required to match the abduction force on a monitor to a target force set to 5% of the maximal voluntary contraction (MVC) force for 60 s. In contrast to previous studies that examined the influence of stressors on pinch grip steadiness, the two stressors did not decrease steadiness. Furthermore, the absence of a change in steadiness contrasted with the increases in cognitive (State-Trait Anxiety Index, Visual Analog Scale) and physiological (heart rate) arousal during the stressor phase and the subsequent decline during recovery. The null effect of the stressors on index finger steadiness may be due to the relative simplicity of the task compared with those examined previously.

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The effect of two different types of stress on locus coeruleus alpha-2 receptor binding

Cited by 24 publications

References 21 publications

Reward expectation, orientation of attention and locus coeruleus‐medial frontal cortex interplay during learning

Reward expectation, orientation of attention and locus coeruleus‐medial frontal cortex interplay during learning

Repeated tail pinch leads to desensitization of postsynaptic α 2 -adrenoceptors which modulate the jaw-opening reflex in the rat

Comparison of the influence of two stressors on steadiness during index finger abduction

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