A major problem with drugs of abuse is the return to drug use after a period of abstinence (relapse). A contributing factor to relapse is the withdrawal-induced anxiety and depression, which stimulates re-administration as a form of self-medication. Supersensitivity of 5-HT2A receptors is associated with withdrawal from several drugs of abuse such as cocaine, MDMA and methamphetamine. Recent evidence also suggests that withdrawal from marijuana-related compounds (cannabinoids) is associated with supersensitivity of 5-HT2A receptors. 5-HT2A receptors in the amygdala and hypothalamic paraventricular nucleus (PVN) are important for the regulation of mood, impulse control and responses to stress. Therefore, withdrawal-induced increases in 5-HT2A receptor function in these limbic regions may be clinically related to the depressed mood and increased anxiety clinically observed during marijuana withdrawal. We hypothesize that desensitization/downregulation of synaptic cannabinoid receptors mediates the cannabinoid withdrawal-induced supersensitivity of 5-HT2A receptors.
Aim 1 will determine the minimum number of cannabinoid injection days that will produce supersensitivity of 5-HT2A receptor signaling. These studies will identify potential changes in the parameters and mechanisms of cannabinoid and 5-HT2A receptor function in adult male rats withdrawn from chronic cannabinoid exposure.
Aim 2 will determine whether down-regulation of synaptic cannabinoid receptors will produce supersensitivity of 5-HT2A receptor signaling. These studies will examine fundamental mechanisms regulating 5-HT2A receptor signaling in the forebrain of adult rats withdrawn from cannabinoid exposure. We contend that the proposed studies: (1) will provide a unique opportunity to systematically investigate the signaling mechanisms by which cannabinoid receptors regulate the sensitivity of 5-HT2A receptor systems in vivo, and (2), will further our understanding of the neurobiological mechanisms associated with withdrawal from cannabinoids, in order to refine therapy to reduce craving and relapse.

Public Health Relevance

Withdrawal from marijuana-related compounds (cannabinoids) induces increases in the activity of the neurotransmitter serotonin in brain areas that could be mechanistically involved in mediating propensity for relapse, and thereby stimulate re- administration as a form of self-medication. The proposed studies will provide a unique opportunity to systematically investigate the signaling mechanisms by which cannabinoid receptors regulate the sensitivity of 5-HT2A receptor systems in vivo. These studies will further our understanding of the neurobiological mechanisms associated with withdrawal from cannabinoids, in order to refine therapy to reduce craving and relapse.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Small Research Grants (R03)
Project #
5R03DA024329-02
Application #
7817057
Study Section
Neuroendocrinology, Neuroimmunology, and Behavior Study Section (NNB)
Program Officer
Frankenheim, Jerry
Project Start
2009-05-01
Project End
2012-04-30
Budget Start
2010-05-01
Budget End
2012-04-30
Support Year
2
Fiscal Year
2010
Total Cost
$73,458
Indirect Cost
Name
University of Kansas Lawrence
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
076248616
City
Lawrence
State
KS
Country
United States
Zip Code
66045
Franklin, Jade M; Mathew, Matt; Carrasco, Gonzalo A (2013) Cannabinoid-induced upregulation of serotonin 2A receptors in the hypothalamic paraventricular nucleus and anxiety-like behaviors in rats. Neurosci Lett 548:165-9
Franklin, Jade M; Vasiljevik, Tamara; Prisinzano, Thomas E et al. (2013) Cannabinoid agonists increase the interaction between ?-Arrestin 2 and ERK1/2 and upregulate ?-Arrestin 2 and 5-HT(2A) receptors. Pharmacol Res 68:46-58
Franklin, Jade M; Carrasco, Gonzalo A (2013) G-protein receptor kinase 5 regulates the cannabinoid receptor 2-induced up-regulation of serotonin 2A receptors. J Biol Chem 288:15712-24
Franklin, J M; Vasiljevik, T; Prisinzano, T E et al. (2013) Cannabinoid 2 receptor- and beta Arrestin 2-dependent upregulation of serotonin 2A receptors. Eur Neuropsychopharmacol 23:760-7
Franklin, Jade M; Carrasco, Gonzalo A (2013) Cannabinoid receptor agonists upregulate and enhance serotonin 2A (5-HT(2A)) receptor activity via ERK1/2 signaling. Synapse 67:145-59
Franklin, Jade M; Carrasco, Gonzalo A (2012) Cannabinoid-induced enhanced interaction and protein levels of serotonin 5-HT(2A) and dopamine D? receptors in rat prefrontal cortex. J Psychopharmacol 26:1333-47