scholarly journals The evolution and comparative neurobiology of endocannabinoid signalling

2012 ◽  
Vol 367 (1607) ◽  
pp. 3201-3215 ◽  
Author(s):  
Maurice R. Elphick

CB 1 - and CB 2 -type cannabinoid receptors mediate effects of the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide in mammals. In canonical endocannabinoid-mediated synaptic plasticity, 2-AG is generated postsynaptically by diacylglycerol lipase alpha and acts via presynaptic CB 1 -type cannabinoid receptors to inhibit neurotransmitter release. Electrophysiological studies on lampreys indicate that this retrograde signalling mechanism occurs throughout the vertebrates, whereas system-level studies point to conserved roles for endocannabinoid signalling in neural mechanisms of learning and control of locomotor activity and feeding. CB 1 /CB 2 -type receptors originated in a common ancestor of extant chordates, and in the sea squirt Ciona intestinalis a CB 1 /CB 2 -type receptor is targeted to axons, indicative of an ancient role for cannabinoid receptors as axonal regulators of neuronal signalling. Although CB 1 /CB 2 -type receptors are unique to chordates, enzymes involved in biosynthesis/inactivation of endocannabinoids occur throughout the animal kingdom. Accordingly, non-CB 1 /CB 2 -mediated mechanisms of endocannabinoid signalling have been postulated. For example, there is evidence that 2-AG mediates retrograde signalling at synapses in the nervous system of the leech Hirudo medicinalis by activating presynaptic transient receptor potential vanilloid-type ion channels. Thus, postsynaptic synthesis of 2-AG or anandamide may be a phylogenetically widespread phenomenon, and a variety of proteins may have evolved as presynaptic (or postsynaptic) receptors for endocannabinoids.

2021 ◽  
Vol 22 (4) ◽  
pp. 1863
Author(s):  
Philippe A. Melas ◽  
Maria Scherma ◽  
Walter Fratta ◽  
Carlo Cifani ◽  
Paola Fadda

Cannabidiol (CBD) is the most abundant non-psychoactive component of cannabis; it displays a very low affinity for cannabinoid receptors, facilitates endocannabinoid signaling by inhibiting the hydrolysis of anandamide, and stimulates both transient receptor potential vanilloid 1 and 2 and serotonin type 1A receptors. Since CBD interacts with a wide variety of molecular targets in the brain, its therapeutic potential has been investigated in a number of neuropsychiatric diseases, including anxiety and mood disorders. Specifically, CBD has received growing attention due to its anxiolytic and antidepressant properties. As a consequence, and given its safety profile, CBD is considered a promising new agent in the treatment of anxiety and mood disorders. However, the exact molecular mechanism of action of CBD still remains unknown. In the present preclinical review, we provide a summary of animal-based studies that support the use of CBD as an anxiolytic- and antidepressant-like compound. Next, we describe neuropharmacological evidence that links the molecular pharmacology of CBD to its behavioral effects. Finally, by taking into consideration the effects of CBD on DNA methylation, histone modifications, and microRNAs, we elaborate on the putative role of epigenetic mechanisms in mediating CBD’s therapeutic outcomes.


2013 ◽  
Vol 114 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Yu-Jung Lin ◽  
You Shuei Lin ◽  
Ching Jung Lai ◽  
Zung Fan Yuan ◽  
Ting Ruan ◽  
...  

The terminals of vagal lung C fibers (VLCFs) express various types of pharmacological receptors that are important to the elicitation of airway reflexes and the development of airway hypersensitivity. We investigated the blockade of the reflex and afferent responses of VLCFs to intravenous injections of agonists using perivagal treatment with antagonists (PAT) targeting the transient receptor potential vanilloid 1, P2X, and 5-HT3 receptors in anesthetized rats. Blockading these responses via perivagal capsaicin treatment (PCT), which blocks the neural conduction of C fibers, was also studied. We used capsaicin, α,β-methylene-ATP, and phenylbiguanide as the agonists, and capsazepine, iso-pyridoxalphosphate-6-azophenyl-2′,5′-disulfonate, and tropisetron as the antagonists of transient receptor potential vanilloid 1, P2X, and 5-HT3 receptors, respectively. We found that each of the PATs abolished the VLCF-mediated reflex apnea evoked by the corresponding agonist, while having no effect on the response to other agonists. Perivagal vehicle treatment failed to produce any such blockade. These blockades had partially recovered at 3 h after removal of the PATs. In contrast, PCT abolished the reflex apneic response to all three agonists. Both PATs and PCT did not affect the myelinated afferent-mediated apneic response to lung inflation. Consistently, our electrophysiological studies revealed that each of the PATs prevented the VLCF responses to the corresponding agonist, but not to any other agonist. PCT inevitably prevented the VLCF responses to all three agonists. Thus these PATs selectively blocked the stimulatory action of corresponding agonists on the VLCF terminals via mechanisms that are distinct from those of PCT. PAT may become a novel intervention for studying the pharmacological modulation of VLCFs.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lejla Zubcevic ◽  
William F Borschel ◽  
Allen L Hsu ◽  
Mario J Borgnia ◽  
Seok-Yong Lee

Temperature-sensitive transient receptor potential vanilloid (thermoTRPV) channels are activated by ligands and heat, and are involved in various physiological processes. ThermoTRPV channels possess a large cytoplasmic ring consisting of N-terminal ankyrin repeat domains (ARD) and C-terminal domains (CTD). The cytoplasmic inter-protomer interface is unique and consists of a CTD coiled around a β-sheet which makes contacts with the neighboring ARD. Despite much existing evidence that the cytoplasmic ring is important for thermoTRPV function, the mechanism by which this unique structure is involved in thermoTRPV gating has not been clear. Here, we present cryo-EM and electrophysiological studies which demonstrate that TRPV3 gating involves large rearrangements at the cytoplasmic inter-protomer interface and that this motion triggers coupling between cytoplasmic and transmembrane domains, priming the channel for opening. Furthermore, our studies unveil the role of this interface in the distinct biophysical and physiological properties of individual thermoTRPV subtypes.


2018 ◽  
Vol 14 ◽  
pp. 1-13
Author(s):  
Angelika Andrzejewska ◽  
Klaudia Staszak ◽  
Marta Kaczmarek-Ryś ◽  
Ryszard Słomski ◽  
Szymon Hryhorowicz

The endocannabinoid system (ECS) consists of the endocannabinoids, cannabinoid receptors and the enzymes that synthesize and degrade endocannabinoids. The whole EC system plays an important role in the proper functioning of the central and autonomic nervous system. ECS is involved in the regulation of the body energy and in the functioning of the endocrine system. It can affect on the regulation of emotional states, motoric movement, operations of the endocrine, immune and digestive system. Many of the effects of cannabinoids are mediated by G coupled –protein receptors: CB1, CB2 and GPR55 but also of transient receptor potential channels (TRPs) which not only induce the sensation of pain but also support inflammation via secretion of pro-inflammatory neuropeptides. In this review work we briefly summarize the role and action of cannabinoid receptors CB1 and CB2, protein-coupled receptor 55 (GPR55) and transient receptor potential vanilloid 1 (TRPV1).


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