Changes in the Brain Endocannabinoid System in Rat Models of Depression

Smaga, Irena; Jastrzębska, Joanna; Zaniewska, Magdalena; Bystrowska, Beata; Gawliński, Dawid; Faron-Górecka, Agata; Broniowska, Żaneta; Miszkiel, Joanna; Filip, Małgorzata

doi:10.1007/s12640-017-9708-y

Cited by 36 publications

(36 citation statements)

References 87 publications

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“…Significant alterations of the ECS in several rat brain structures have been detected in the OBX model. The levels of endogenous cannabinoids were changed in prefrontal cortex, hippocampus, striatum and nucleus accumbens; the CB1 receptor expression was lower in the hippocampus, dorsal striatum, and nucleus accumbens and the CB2 receptor expression decreased in the prefrontal cortex and hippocampus (Smaga et al, 2017). Eisenstein et al (2009) provided evidence for dysfunction of ECS in olfactory bulbectomized rats which may have an impact on the functional activity of other neurotransmitter systems.…”

Section: Discussionmentioning

confidence: 96%

Subchronic effects of ligands of cannabinoid receptors on learning and memory processes of olfactory bulbectomized rats

Velikova

Doncheva

Tashev

2020

Acta Neurobiologiae Experimentalis

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The brain endocannabinoid system has been shown to play a role in many physiological processes, including mood, learning and memory. It is also involved in the pathogenesis of anxiety, depression, mood disorders, as well as neurodegenerative disorders, although the exact mechanisms by which cannabinoid receptors interfere in these disorders are not well established. The aim of the present study was to evaluate the effects of cannabinoid ligands HU-210 (CB1 receptor agonist) and SR 141716A (CB1 receptor antagonist) on learning and memory processes of rats with depressive-like state, induced by bilateral olfactory bulbectomy. The bilateral olfactory bulbectomy (OBX) is a validated model of depression, which can be used also as an animal model of Alzheimer's disease. We found that the subchronic treatment of OBX rats with HU 210 and SR 141716A exerted modulatory effect on rat's performance in both active avoidance (shuttle box) and passive avoidance (step through) tests. HU 210 ameliorated the memory deficits of OBX rats; however, the scores of the sham-operated controls had not been reached. SR 141716A modified the avoidance performance in OBX rats and showed a memory enhancing effect in the sham-operated rats. Our findings suggest that CB1 receptors might be involved in avoidance learning and memory acquisition in OBX rats.

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Section: Discussionmentioning

confidence: 96%

Subchronic effects of ligands of cannabinoid receptors on learning and memory processes of olfactory bulbectomized rats

Velikova

Doncheva

Tashev

2020

Acta Neurobiologiae Experimentalis

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“…In the case of CB 2 receptors, few data are available, and the results are not always consistent. In an animal model based on the surgical removal of the olfactory bulbs (bulbectomy—an animal model of depression), decreased levels of AEA and CB 2 expression in the hippocampus were reported (Smaga et al, 2017 ). Furthermore, overexpression of CB 2 receptors induced a depression-resilient phenotype after chronic stress, but no alterations in hippocampal BDNF levels.…”

Section: Stress-induced Modulation Of the Ecb Signaling In The Hippocmentioning

confidence: 99%

Cannabinoid Modulation of the Stressed Hippocampus

Scarante

Vila-Verde

Detoni

et al. 2017

Front. Mol. Neurosci.

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Exposure to stressful situations is one of the risk factors for the precipitation of several psychiatric disorders, including Major Depressive Disorder, Posttraumatic Stress Disorder and Schizophrenia. The hippocampal formation is a forebrain structure highly associated with emotional, learning and memory processes; being particularly vulnerable to stress. Exposure to stressful stimuli leads to neuroplastic changes and imbalance between inhibitory/excitatory networks. These changes have been associated with an impaired hippocampal function. Endocannabinoids (eCB) are one of the main systems controlling both excitatory and inhibitory neurotransmission, as well as neuroplasticity within the hippocampus. Cannabinoids receptors are highly expressed in the hippocampus, and several lines of evidence suggest that facilitation of cannabinoid signaling within this brain region prevents stress-induced behavioral changes. Also, chronic stress modulates hippocampal CB1 receptors expression and endocannabinoid levels. Moreover, cannabinoids participate in mechanisms related to synaptic plasticity and adult neurogenesis. Here, we discussed the main findings supporting the involvement of hippocampal cannabinoid neurotransmission in stress-induced behavioral and neuroplastic changes.

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“…In addition, the correlation between cognitive dysfunction and OD may be related to the mutual pathways of OFC and subcortical structures 12,13 . The OFC and rostral insula bilaterally 14 are the secondary olfactory neuroanatomic structures taking charge of chemosensory processing 15 while the primary olfactory structures generate from the piriform cortex, entorhinal cortex, amygdala, and hippocampus 16 receiving the inputs from the tractus olfactoriusta projected from the olfactory bulb.…”

mentioning

confidence: 99%

Association between olfactory function and inhibition of emotional competing distractors in major depressive disorder

Wang

Jin

Wang

et al. 2020

Sci Rep

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We aimed to investigate the changes of olfaction of major depressive disorder (MDD) before and after medical treatment, and to preliminarily scrutinize the association between the olfactory function and the severity of depressive symptoms, response inhibition, and emotional responding. Forty-eight medicine-naïve MDD patients plus 33 healthy controls (HC) matched on gender, ages, and level of education, were recruited in the test group. The Chinese Smell Identification Test (CSIT), Self-reported Olfactory Scale (SROS), 17-item Hamilton Depression Rating Scale (HAMD-17), Hamilton Anxiety Rating Scale (HAMA), and mean reaction time/accuracy rate (ΔMRt) of emotional Stroop test were measured. The patients were assessed before the treatment (baseline) and 3 months after the treatment (follow-up). The data at the baseline level were measured then associated using multiple linear regression stepwise analysis. The MDD patients had lower scores of the CSIT and SROS and longer ΔMRt at baseline level compared to Hc while the ΔMRt of MDD patients remained longer after 3-month treatment (p's < 0.05). At the baseline level, the regression equation including age and ΔMRt of negative word-color congruent (NEG-C), was finally observed as follows: y(CSIT) = 10.676-0.063 × 1-0.002 × 2, [x 1 = the age(y), x 2 = the NEG-C (ms)]. The olfactory function of MDD appears to be correlated negatively with the age and the ΔMRT of negative stimuli before treatment. After the remission of MDD, the olfactory dysfunction was improved, which might be regarded as a responding phenotype of brain function of MDD rather than the emotional responding. Major depressive disorder (MDD) and olfaction disorder (OD) are both chronic diseases that affect human being's life quality 1. A systematic review on ten studies chosen for using the Sniffin' Sticks Test and the 40-item Smell Identification Test assessed to reveal the relationship between depression and OD. Results show that both of the olfactory threshold, olfactory discrimination, and olfactory identification were influenced by depression 2. Furthermore, symptoms of depression worsen with the severity of olfactory loss 3. It was demonstrated that olfactory bulbectomy, as a well-known method, could induce an animal model of depression in animal experiment 4. In depression-related brain areas including hippocampus, frontal cortex and hypothalamus, the turnover of serotonin and dopamine decreases in the olfactory bulbectomized rats 5. Similarly, in human studies, Cory et al. 6 found that patients with depression have decreased activities in the left medial orbitofrontal cortex (OFC) accompanied with the defect of the olfactory identification. However, Zucco et al. 7 argued that the changes mentioned above occur in patients with the MDD only, not with the mild or moderate depressive disorder. In the neural circuits involved in emotional processing 8 , these key structures such as amygdala, hippocampus, anterior cingulate cortex(ACC) and OFC, are the imperative functional regions of the human olfactory map...

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Changes in the Brain Endocannabinoid System in Rat Models of Depression

Cited by 36 publications

References 87 publications

Subchronic effects of ligands of cannabinoid receptors on learning and memory processes of olfactory bulbectomized rats

Subchronic effects of ligands of cannabinoid receptors on learning and memory processes of olfactory bulbectomized rats

Cannabinoid Modulation of the Stressed Hippocampus

Association between olfactory function and inhibition of emotional competing distractors in major depressive disorder

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