Abstract ▼ AI-Helper

In response to stress, psychological and physiological resources are allocated towards the systems that are needed for rapid responses. Various stress responses can be categorized into either ‘active’ coping or ‘passive’ coping. Active coping occurs when the situation is assessed as manageable and i...

In response to stress, psychological and physiological resources are allocated towards the systems that are needed for rapid responses. Various stress responses can be categorized into either ‘active’ coping or ‘passive’ coping. Active coping occurs when the situation is assessed as manageable and it supports the removal or avoidance of the stressor. The autonomic changes associated with active coping is mediated predominantly by sympathetic activation. However, when a stressor is appraised as uncontrollable, passive coping, typically manifested by immobilization or freezing, is elicited to preserve energy and resources as well as to reduce emotional impact.
The striatum, the major input structure in the basal ganglia, has been implicated in complex behaviors such as motor control, learning, decision-making, reward and aversion. The striatum is mainly composed of medium spiny neurons (MSNs) that are divided into those expressing dopamine receptor D1 (direct pathway), and those expressing D2 receptor (indirect pathway).
Here, I examined the effect of neuronal activity in the striatum of mice within the context of stress coping behavior. For direct modulation of neuronal activity in direct-/indirect pathway, I used the designer receptors exclusively activated by designer drugs (DREADD) system. Following bilateral injection of hM3Dq and hM4Di-expressing AAV in the dorsomedial striatum (DMS), mice were tested for stress coping behavior with clozapine-N-oxide (CNO) or vehicle injection (i.p.). I found that the activation or inhibition of D1-expressing MSNs and D2-expressing MSNs in the dorsomedial striatum (DMS) supported the active stress coping and passive coping behavior respectively, after chronic predator stress exposure in mice.
My results revealed that the direct-/indirect pathway of DMS has distinct functional roles in the behavioral manifestation of stress coping strategies.

Keyword