Stress
Endogenous cannabinoid signaling is essential for stress adaptation.
Secretion of glucocorticoid hormones during stress produces an array of physiological changes that are adaptive and beneficial in the short term. In the face of repeated stress exposure, however, habituation of the glucocorticoid response is essential as prolonged glucocorticoid secretion can produce deleterious effects on metabolic, immune, cardiovascular, and neurobiological function...The present findings demonstrate an important role for endocannabinoid signaling in the process of stress HPA habituation, and suggest that AEA and 2-AG modulate different components of the adrenocortical response to repeated stressor exposure.
Regulation of endocannabinoid signaling by stress: implications for stress-related affective disorders.
The endocannabinoid system is a widely distributed, neuromodulatory system which serves an integral role in regulating synaptic transmission. The presence of this system in stress-responsive neural circuits suggests that it may play a critical role in regulating neuroendocrine and behavioral responses to stress.
Functional interactions between stress and the endocannabinoid system: from synaptic signaling to behavioral output.
Endocannabinoid signaling is distributed throughout the brain, regulating synaptic release of both excitatory and inhibitory neurotransmitters. The presence of endocannabinoid signaling within stress-sensitive nuclei of the hypothalamus, as well as upstream limbic structures such as the amygdala, suggests it may play an important role in regulating the neuroendocrine and behavioral effects of stress.
Neuromodulators, stress and plasticity: a role for endocannabinoid signaling.
Any unanticipated threat to survival triggers an immediate sequence of events in the brain that culminate in a coordinated neural, endocrine and behavioural response. There is increasing evidence that stress itself modifies neural circuits. In other words, neural stress circuits learn from stress.
Downregulation of endocannabinoid signaling in the hippocampus following chronic unpredictable stress.
Deficits in cognitive functioning and flexibility are seen following both chronic stress and modulation of endogenous cannabinoid (eCB) signaling. Here, we investigated whether alterations in eCB signaling might contribute to the cognitive impairments induced by chronic stress...This data suggest that stress-induced downregulation of hippocampal eCB signaling contributes to problems in behavioral flexibility and could play a role in the development of perseveratory and ruminatory behaviors in stress-related neuropsychiatric disorders.
Endocannabinoids and stress.
Endogenous cannabinoids play an important role in the physiology and behavioral expression of stress responses. Activation of the hypothalamic-pituitary-adrenal (HPA) axis, including the release of glucocorticoids, is the fundamental hormonal response to stress. Endocannabinoid (eCB) signaling serves to maintain HPA-axis homeostasis, by buffering basal activity as well as by mediating glucocorticoid fast feedback mechanisms.
Stress regulates endocannabinoid-CB1 receptor signaling.
The CB1 cannabinoid receptor is a G protein coupled receptor that is widely expressed throughout the brain...Data are reviewed that support the hypothesis that CB1 receptor signaling is stress responsive and that maintaining robust endocannabinoid/CB1 receptor signaling provides resilience against the development of stress-related pathologies.
Chronic stress impairs α1-adrenoceptor-induced endocannabinoid-dependent synaptic plasticity in the dorsal raphe nucleus.
Collectively, these results indicate that chronic restraint stress impairs the α1-AR LTD by reducing the function of presynaptic CB1 receptors and reveal a novel mechanism by which noradrenaline controls synaptic strength and plasticity in the DRn. They also provide evidence that chronic stress impairs eCB signaling in the DRn, which may contribute, at least in part, to the dysregulation of the stress homeostasis.
Endocannabinoid-mediated modulation of stress responses: physiological and pathophysiological significance.
The stress response is associated with a broad spectrum of physiological and behavioural effects including hypothalamo-pituitary-adrenal (HPA) axis activation, altered central nervous system activity, neuroimmune alterations, anxiety- and depressive-like behaviour and analgesia. While the acute stress response has essential survival value, chronic stress and dysfunction of the stress response can be maladaptive, contributing to the development and severity of psychiatric and pain disorders.
Cannabinoid receptor activation prevents the effects of chronic mild stress on emotional learning and LTP in a rat model of depression.
Most psychiatric disorders are characterized by emotional memory or learning disturbances. Chronic mild stress (CMS) is a common animal model for stress-induced depression. Here we examined whether 3 days of treatment using the CB1/2 receptor agonist WIN55,212-2 could ameliorate the effects of CMS on emotional learning (ie, conditioned avoidance and extinction), long-term potentiation (LTP) in the hippocampal-accumbens pathway, and depression-like symptoms (ie, coping with stress behavior, anhedonia, and weight changes)...The findings suggest that enhancing cannabinoid signaling could represent a novel approach to the treatment of cognitive deficits that accompany stress-related depression.
Cannabinoids ameliorate impairments induced by chronic stress to synaptic plasticity and short-term memory.
Repeated stress is one of the environmental factors that precipitates and exacerbates mental illnesses like depression and anxiety as well as cognitive impairments. We have previously shown that cannabinoids can prevent the effects of acute stress on learning and memory. Here we aimed to find whether chronic cannabinoid treatment would alleviate the long-term effects of exposure to chronic restraint stress on memory and plasticity as well as on behavioral and neuroendocrine measures of anxiety and depression.
The anxiolytic effect of cannabidiol on chronically stressed mice depends on hippocampal neurogenesis: involvement of the endocannabinoid system.
Cannabidiol (CBD), the main non-psychotomimetic component of the plant Cannabis sativa, exerts therapeutically promising effects on human mental health such as inhibition of psychosis, anxiety and depression...These findings support that the anxiolytic effect of chronic CBD administration in stressed mice depends on its proneurogenic action in the adult hippocampus by facilitating endocannabinoid-mediated signalling.
Low-frequency stimulation evokes serotonin release in the nucleus accumbens and induces long-term depression via production of endocannabinoid.
The nucleus accumbens (NAc), a major component of the mesolimbic system, is involved in the mediation of reinforcing and addictive properties of many dependence-producing drugs. Glutamatergic synapses within the NAc can express plasticity, including a form of endocannabinoid (eCB)-long-term depression (LTD). Recent evidences demonstrate cross talk between eCB signaling pathways and those of other receptor systems, including serotonin (5-HT); the extensive colocalization of CB1 and 5-HT receptors within the NAc suggests the potential for interplay between them.
