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The Endocannabinoid System in the Cochlear Nucleus and Its Implications for Tinnitus Treatment

  • Paul F. SmithEmail author

Keypoints

  1. 1.

    One of the main theories of tinnitus is that it is a form of sensory epilepsy, sometimes arising from neuronal hyperactivity in the brainstem cochlear nucleus.

     
  2. 2.

    Antiepileptic drugs have therefore been explored as one potential treatment option.

     
  3. 3.

    Increasing evidence suggests that cannabinoid drugs can also have antiepileptic effects.

     
  4. 4.

    Recently, it has been reported that cannabinoid CB1 and CB2 receptors and the endogenous cannabinoid, 2-arachidonylglycerol (2-AG), are expressed in the cochlear nucleus.

     
  5. 5.

    CB1 receptors appear to negatively regulate the release of glutamate, and it is possible that their down-regulation during the development of tinnitus is responsible for the neuronal hyperactivity associated with the condition.

     
  6. 6.

    This chapter explores the possibility that cannabinoid drugs might be useful in the treatment of tinnitus.

     

Keywords

Tinnitus Cochlear nucleus Cannabinoid receptors Endocannabinoids 

Abbreviations

2-AG

2-Arachidonylglycerol

ACPA

CB1 receptor agonist

CB

Cannabinoid

CN

Cochlear nucleus

9-THC

D9-tetrahydrocannabinol

DAG

Diacylglycerol lipase

DCN

Dorsal cochlear nucleus

FAAH

Fatty acid amide hydrolase

GABA

Gamma-amino butyric acid

IPSC

Inhibitory post-synaptic currents

LTD

Long-term depression

LTP

Long-term potentiation

MAGL

Monoacylglycerol lipase

NAPE-PLD

N-arachidonoylphosphatidylethanola­mine-phospholipase-D

PEA

N-palmitoylethanolamide

PSP

Post-synaptic potentials

SCE

Standard cannabis extracts

VCN

Ventral cochlear nucleus

Notes

Acknowledgements

This research was generously supported by the Jean Cathie Estate.

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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.Department of Pharmacology and Toxicology, School of Medical SciencesUniversity of Otago Medical SchoolDunedinNew Zealand

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