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Construct: Arousal

RDoC Classification

Domain: Arousal and Regulatory Systems

Description

Arousal is a continuum of sensitivity of the organism to stimuli, both external and internal. Arousal:

  1. Facilitates interaction with the environment in a context-specific manner (e.g., under conditions of threat, some stimuli must be ignored while sensitivity to and responses to others is enhanced, as exemplified in the startle reflex),
  2. Can be evoked by either external/environmental stimuli or internal stimuli (e.g., emotions and cognition),
  3. Can be modulated by the physical characteristics and motivational significance of stimuli,
  4. Varies along a continuum that can be quantified in any behavioral state, including wakefulness and low-arousal states including sleep, anesthesia, and coma,
  5. Is distinct from motivation and valence but can covary with intensity of motivation and valence,
  6. May be associated with increased or decreased locomotor activity, and
  7. Can be regulated by homeostatic drives (e.g., hunger, sleep, thirst, sex).

Molecules

Acetylcholine CRF Cytokines Dopamine GABA Ghrelin Glutamate Histamine Hypocretin/Orexin Leptin Neuropeptide Y Norepinephrine Opioid Oxytocin Serotonin Vasopressin

Cells

Basal Forebrain Nuclei Central Nucleus Amygdala Dorsal Raphe Lateral, perifornical, and dorsomedial hypothalamus LDT Locus Coeruleus PPT Tuberomammillary Nucleus Ventral Tegmental Area

Circuits

Basal forebrain nuclei to cortical circuits Brainstem monoaminergic and cholinergic projections to basal forebrain Central Amygdala to monoaminergic and basal forebrain cholinergic nuclei Cholinergic and monoaminergic nuclei projections to thalamic and cortical Circadian and Sleep-related circuits modulate arousal and are modulated by arousal Cortical circuits such as fronto-insular and dorsal anterior cingulate Hypothalamic to thalamic and cortical circuits Projections to midbrain and pontine monoaminergic and cholinergic nuclei Reciprocal hypothalamic Reciprocal NTS-Central N. Amygdala Reciprocoal cholinergic and monoaminergic projection

Physiology

EEG EMG ERP fMRI Neural activity Sex-Specific differences in arousal

Autonomic

Blood pressure Breathing Galvanic skin response Heart Rate Pupil size

HPA axis

ACTH CRF Glucocorticoids

Behavior

Affective states Agitation Cognition Emotional Reactivity Eye Blink Motivated Behavior Motor Activity Sensory Reactivity Startle Waking

Self-Report

ADACL POMS arousal subscale Self-assessment Mannequin

Paradigms

Cardiac Pre-ejection Period Electrodermal Responding Heart rate variability (HRV) Psychomotor Vigilance Task Pupillometry