Defensive emotional reactions and stress: Neuromodulation, from anatomy to behavior

Kokoe Messanvi

    Research output: ThesisThesis fully internal (DIV)

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    Abstract

    A stressor is a physical or psychological stimulus that threatens the homeostasis of an organism. In response to the presence of a stressor, and in order to reinstate the equilibrium, the organism engages physiological and behavioral mechanisms. The neuro-endocrine stress response leads to the release of norepinephrine and the presence of a high concentration of glucocorticoids in the brain. At the behavioral level, the type of response is determined by the physical distance to the threat. This thesis is divided into two independent parts, which deal with two different emotional reactions: with panic-like defensive behavior in response to imminent threat, and with and anxiety, which is the response to distant and unpredictable threats. The second part of this thesis explores the anatomical and molecular basis of the interaction between norepinephrine and glucocorticoids in the amygdala, and the implications of this interaction for anxiety and memory. Not only do these findings provide anatomical evidence of the interaction between norepinephrine and glucocorticoids within the synapse, but they also point to a mechanism of interaction in which norepinephrine signaling can influence glucocorticoid receptors even before the arrival of the hormones to the amygdala. These results also show that norepinephrine and glucocorticoids work together to modulate anxiety-like behavior, similarly as in memory mechanisms.These data suggest that glucocorticoids simultaneously affect anxiety and memory, possibly via a modification of morphology and activity of the neurons in the amygdala.
    Translated title of the contributionDefensieve emotionele reacties en stress
    Original languageEnglish
    QualificationDoctor of Philosophy
    Awarding Institution
    • University of Groningen
    Supervisors/Advisors
    • ter Horst, Gert, Supervisor
    Award date8-Sep-2014
    Place of Publication[S.l.]
    Publisher
    Print ISBNs978-90-367-7150-4
    Electronic ISBNs978-90-367-7149-8
    Publication statusPublished - 2014

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