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Taffe Lab: E-cigarette model of vapor inhalation for rats

Our interest in developing inhalation techniques for delivering psychoactive drugs to rats arose from the realization that increasing numbers of people were using non-combusted methods for inhalation.

Chamber SchematicSo called "vaping" procedures break down into two categories at present. One method heats the marijuana to a high temperature below the combustion threshold and collects cannabinoid-infused air into a balloon (Volcano® type devices). A second method uses e-cigarette technology which we have adapted for our research program. The picture to the left illustrates a standard rat cage fitted with a sealed lid. This permits the controlled airflow through the chamber and the incorporation of vapor from an e-cigarette cartridge upon demand.

Additional reading can be found in the tlneuro blog Vape inhalation archive.

Cannabinoids

A primary focus of our work is on the primary active constituent of marijuana ( Δ9-tetrahydrocannabinol; THC). It appears that growing numbers of cannabis consumers are using non-combustible techniques, based on the evidence of a plethora of Web sites advertising methods, an emerging literature showing human practices (Giroud et al, 2015, Morean et al, 2015) and from suggestions that e-cigarette delivery may offer a safer alternative for medical cannabis consumers (Varlet et al, 2016). Our first paper (Nguyen et al, 2016 in press) demonstrated that vapor inhalation of THC reduces body temperature, decreases locomotor activity and attenuates detection of a noxious stimulus. These are three of the four traditional behavioral measures of cannabinoid activity in a rodent and thus verify the efficacy of this approach.

Psychostimulants

One of the primary interests of the laboratory is the use and abuse of psychostimulants including methamphetamine, MDMA and substituted cathinone stimulants. Inhaled use of methamphetamine is more common than other routes of administration in habitual and dependent users. Furthermore, the SAMHSA/TEDS treatment admission database for 2012 shows 4.7% of treatment seekers in the USA were admitted for smoked cocaine vs 2.2% for other routes of cocaine administration as the primary reason for treatment. Despite this, preclinical models which incorporate inhaled exposure to psychomotor stimulants are not commonly available. E-cigarette technology has further facilitated inhalation of methamphetamine (Evans 2014; Rass et al. 2015), “bath salts” (Johnson and Johnson 2014; Rass et al. 2015) and  “flakka” (α-pyrrolidinopentiophenone; alpha-PVP) as reported  (Anderson 2015) in one case of paranoid public behavior. Additional evidence exists in popular drug-user forums such as www.bluelight.org host sub-threads for the discussion of administering several different stimulants in e-cigarettes. We have thus been working to determine if active doses of psychostimulants can be delivered to rats using this technology.

Vape Publications

Vendruscolo, J.C.M., Tunstall, B.J., Carmack, S.A., Schmeichel, B.E., Lowery-Gionta, E.G., Cole, M., George, O., Vandewater, S.A., Taffe, M.A., Koob, G.F. and Vendruscolo, L.F. Compulsive-like sufentanil vapor self-administration in the rat, Neuropsychopharmacology, 2017, in press.

Nguyen, J.D., Bremer, P.T., Hwang, C.S., Vandewater, S.A., Collins, K.C., Creehan, K.M., Janda, K.D. and Taffe, M.A. Effective active vaccination against methamphetamine in female rats, Drug Alcohol Depend, 2017, 175:179-186. [ Publisher Site ][ PubMed ]

Nguyen, J.D., Aarde, S.M., Cole, M.,  Vandewater, S.A., Grant, Y. and Taffe, M.A. Locomotor stimulant and rewarding effects of inhaling methamphetamine, MDPV and mephedrone via electronic cigarette-type technology, Neuropsychopharmacology, 2016, 41:2759-2771. [ Publisher Site ][ PubMed]

Nguyen, J.D., Aarde, S.M.,  Vandewater, S.A., Grant, Y., Stouffer, D.G., Parsons, L.H., Cole, M. and Taffe, M.A. Inhaled delivery of Δ9-tetrahydrocannabinol (THC) to rats by e-cigarette vapor technology, Neuropharmacology, 2016, 109:112-120. [ Publisher Site ][ PubMed ]

Vapor inhalation research in The Taffe Laboratory is supported by subcontract of USPHS Grant R44 DA041967 awarded to La Jolla Alcohol Research, Inc.