Differential Regulation of Synaptic Inputs by Constitutively Released Endocannabinoids and Exogenous Cannabinoids

@article{Hentges2005DifferentialRO,
  title={Differential Regulation of Synaptic Inputs by Constitutively Released Endocannabinoids and Exogenous Cannabinoids},
  author={Shane T. Hentges and Malcolm J. Low and John T. Williams},
  journal={The Journal of Neuroscience},
  year={2005},
  volume={25},
  pages={9746 - 9751}
}
Endocannabinoid release from a single neuron has been shown to cause presynaptic inhibition of transmitter release at many different sites. Here, we demonstrate that hypothalamic proopiomelanocortin (POMC) neurons release endocannabinoids continuously under basal conditions, unlike other release sites at which endocannabinoid production must be stimulated. The basal endocannabinoid release selectively inhibited GABA release onto POMC neurons, although exogenous administration of cannabinoid… 

Figures from this paper

Multiple Forms of Endocannabinoid and Endovanilloid Signaling Regulate the Tonic Control of GABA Release
TLDR
The findings indicate that constitutive CB1 activity has pivotal function in the tonic control of hippocampal GABA release and indicate that the synaptic effects of tonic 2-AG release are tightly controlled by presynaptic MGL activity and also by postsynaptic endovanilloid signaling and FAAH activity.
Presynaptic Monoacylglycerol Lipase Activity Determines Basal Endocannabinoid Tone and Terminates Retrograde Endocannabinoid Signaling in the Hippocampus
TLDR
Investigation of how MGL regulates endocannabinoid signaling and influences synaptic transmission in the hippocampus finds that MGL inhibitors caused a gradual suppression of cannabinoid-sensitive IPSCs in cultured hippocampal neurons, and suggests that presynaptic MGL contributes to degradation of constitutively produced 2-AG and prevention of its accumulation around Presynaptic terminals.
Developmental alteration of endocannabinoid retrograde signaling in the hippocampus.
TLDR
Evidence is obtained that tonic endocannabinoid release suppresses GABAergic transmission in the mature but not the neonatal hippocampus, and the differential DSI magnitude at different stages of maturation could alter synaptic plasticity and learning and memory during hippocampal development.
Cannabinoid and vanilloid pathways mediate opposing forms of synaptic plasticity in corticotropin‐releasing hormone neurons
TLDR
It is shown that activation of CRH neurons can drive the release of signaling molecules that activate parallel endocannabinoid and endovanilloid receptor pathways to mediate opposing forms of synaptic plasticity.
Retrograde Regulation of GABA Transmission by the Tonic Release of Oxytocin and Endocannabinoids Governs Postsynaptic Firing
TLDR
It is demonstrated that inhibitory, GABA synapses specifically onto oxytocin (OT)-producing neurosecretory cells exhibit a low Pr that is relatively uniform at multiple synapses onto the same cell, a two-step process that requires the tonic release of OT from the postsynaptic cell.
Differential effect of cannabinoid agonists and endocannabinoids on histamine release from distinct regions of the rat brain
TLDR
The modulatory effect of cannabimimetic compounds on histamine release apparently did not involve inhibition of γ‐aminobutyric acid (GABA)ergic neurotransmission, which provides the main inhibitory input to the histaminergic neurons in the hypothalamus, as local infusions of ACEA did not modify GABA release from the TMN.
Endocannabinoid-mediated control of synaptic transmission.
TLDR
This review aims to integrate the current understanding of functions of the endocannabinoid system, especially focusing on the control of synaptic transmission in the brain, and summarizes recent electrophysiological studies carried out on synapses of various brain regions and discusses how synaptic transmission is regulated by endoc cannabinoidoid signaling.
Presynaptic modulation by endocannabinoids.
  • D. Lovinger
  • Biology
    Handbook of experimental pharmacology
  • 2008
TLDR
It is now clear that presynaptic depression is the major physiological role for the CB1 receptor and endocannabinoids play a key role in one form of long-term synaptic depression (LTD) that involves a longlasting decrease in neurotransmitter release.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 52 REFERENCES
Activation of Muscarinic Acetylcholine Receptors Enhances the Release of Endogenous Cannabinoids in the Hippocampus
TLDR
A new role of the muscarinic cholinergic system in mammalian brain is revealed andReplication of the effects of CCh by blocking acetylcholinesterase with eserine suggests that mAChR-mediated endocannabinoid release is physiologically relevant.
Endogenous cannabinoids mediate retrograde signalling at hippocampal synapses
TLDR
The transient suppression of GABA-mediated transmission that follows depolarization of hippocampal pyramidal neurons is mediated by retrograde signalling through release of endogenous cannabinoids, indicating that the function of endogenous cannabinoid released by depolarized hippocampal neurons might be to downregulate GABA release.
Metabotropic Glutamate Receptors Drive the Endocannabinoid System in Hippocampus
TLDR
It is concluded that group I mGluR-induced enhancement of DSI, and suppression of IPSCs, is actually mediated by endocannabinoids, which opens up new approaches to the investigation of cannabinoid actions in the brain.
Formation and inactivation of endogenous cannabinoid anandamide in central neurons
TLDR
It is reported that anandamide is produced in and released from cultured brain neurons in a calcium ion-dependent manner when the neurons are stimulated with membrane-depolarizing agents, indicating that multiple biochemical pathways may participate in an andamide formation in brain tissue.
Presynaptic Cannabinoid Sensitivity Is a Major Determinant of Depolarization-Induced Retrograde Suppression at Hippocampal Synapses
TLDR
Results indicate that presynaptic cannabinoid sensitivity is a major factor that determines the extent of DSI and DSE, and that both DSE and DSI were mediated by the cannabinoid CB1 receptor.
Nongenomic Glucocorticoid Inhibition via Endocannabinoid Release in the Hypothalamus: A Fast Feedback Mechanism
TLDR
A mechanism of rapid glucocorticoid feedback inhibition of hypothalamic hormone secretion via endocannabinoid release in the PVN is revealed and a link between the actions of glucoc Corticorticoids and cannabinoids in the hypothalamus that regulate stress and energy homeostasis is provided.
Exogenous and Endogenous Cannabinoids Control Synaptic Transmission in Mice Nucleus Accumbens
TLDR
A major role of the eCB system in long‐term synaptic plasticity is suggested and insights into how cannabis derivatives, such as marijuana, alter normal eCB functions in the brain reward system are given.
GABA Release from Proopiomelanocortin Neurons
TLDR
The results suggest that proopiomelanocortin neurons can exert rapid inhibitory effects via the release of GABA, in addition to the more sustained actions provided by POMC peptides, but this rapid inhibition may not play a major role within local hypothalamic circuits, but rather is likely to be important in more distant projection areas as indicated by the colocalization of vesicular GABA transporter immunoreactivity predominately in extrahypothalamic PomC terminals.
Brief presynaptic bursts evoke synapse-specific retrograde inhibition mediated by endogenous cannabinoids
TLDR
It is reported that brief bursts of presynaptic activity evoked endocannabinoid release, which strongly inhibited parallel fiber–to–Purkinje cell synapses in rat cerebellar slices, thereby dynamically fine-tuning the properties of synaptic integration.
Persistently active cannabinoid receptors mute a subpopulation of hippocampal interneurons.
TLDR
It is reported that persistently active cannabinoid receptors, the site of action of endocannabinoids, and the psychostimulants marijuana and hashish, switch off the output (mute) of a unique class of hippocampal INs.
...
1
2
3
4
5
...