Possible involvement of endocannabinoids in the increase of morphine consumption in maternally deprived rat

The Endocannabinoid/Endovanilloid System and Depression

“…These data parallel observations in the striatum of olfactory-bulbectomized rats [ 22 ] and in the hippocampus of Wistar-Kyoto rats [ 23 ], when AEA tissue concentrations were decreased. These findings conflict with recent data in adult rats after a maternal deprivation procedure, in which the levels of AEA increased in some brain areas, such as the nucleus accumbens, caudate-putamen nucleus and mesencephalon [ 24 ] (Table 1 ). The reasons for these differences are unknown, however, several factors such as the ages of the animals and nervous system development, should be taken into account when comparing the levels of AEA.…”

“…Animal models of depression and stress procedures alter rodent 2-AG brain tissue concentrations. Thus, the 2-AG either decreased in the ventral striatum of olfactory-bulbectomized rats [ 22 ] or increased in the thalamus after a chronic mild stress (CMS) procedure [ 25 ], in the hypothalamus and midbrain after a CUS procedure [ 20 ], in the frontal cortex, hippocampus and hypothalamus after repeated social stress [ 21 ], or in the hippocampus and nucleus accumbens after maternal deprivation [ 24 , 26 ] (Table 1 ). On the whole, the evidence from preclinical modelsof dysfunction in the eCB levelsis dependent on brain-region and the research tools (the procedures used to generate “ depressed” animals ) .…”

CB1 cannabinoid receptor ligands augment the antidepressant-like activity of biometals (magnesium and zinc) in the behavioural tests

“…One of the ideas is existence of the functional pools of receptors responsible for manifestation of the prodepressive and antidepressant effect, which was suggested by Patel and Hillard . Or, following Hill and Gorzałka, the applied mice strain, drug dose, as well as testing conditions, could have been the decisive factors responsible for induction of the antidepressant‐like instead of depressive‐like changes in the endocannabinoid system. As for Ostadhadi et al ., they do not exclude the possibility that the specific effects of cannabinoid ligands in mood disorders are mediated via certain subtypes of cannabinoid receptors that have not been classified yet.…”

“…Several authors claim that the depressive‐like symptoms are associated with a deficiency in the endocannabinoid pathways, whereas the others demonstrated the opposite results. For example, reduced levels of anandamide (one of the major endogenous cannabinoids) were detected in different brain areas of rats serving as a genetic animal model of depression (Wistar‐Kyoto rats), of rodents exposed to the chronic unpredictable stress or social defeat stress, as well as of rats subjected to olfactory bulbectomy, whereas Naudon et al . demonstrated an increased concentration of anandamide in maternally deprived animals.…”

Interacting Cannabinoid and Opioid Receptors in the Nucleus Accumbens Core Control Adolescent Social Play

“…CB1R and opioid receptors (OR) exhibit overlapping mechanisms and they are likely interact to modulate multiple behaviors (Navarro et al, 2001; Fattore et al, 2005; Mackie, 2005; Hudson et al, 2010; Pertwee, 2010; Befort, 2015) starting at early developmental stages (Ellgren et al, 2007, 2008; Biscaia et al, 2008; Naudon et al, 2013). Indeed, opioid and eCB neurotransmission have been shown to interact in the modulation of social play (Trezza and Vanderschuren, 2008a, 2009), but it is not known whether this interaction occurs at the level of the NAc.…”