Differential effects of cannabis extracts and pure plant cannabinoids on hippocampal neurones and glia.
Duncan Ryan, Alison J Drysdale, Roger G Pertwee, Bettina Platt
Neuroscience Letters November 20, 2006 DOI: 10.1016/j.neulet.2006.09.008 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | In vitro cell culture study Peer reviewed |
|---|---|
| Population | Cultured hippocampal neurones and glia |
| Interventions | Delta(9)-tetrahydrocannabinol (THC) cannabidiol (CBD) mock extracts |
| Dose | 1 microM pure THC, 1 microM pure CBD |
| Topics | Cannabis |
| Key points | THC, like CBD, elevated intracellular calcium in cultured hippocampal neurones and glia. Cannabis extracts produced responses that differed from those of the pure compounds, and a 1:1 mixture of high-THC and high-CBD extracts evoked larger calcium responses and higher maximal responder rates than a 1:1 mixture of pure THC and CBD, which the authors interpret as evidence of synergy and of unidentified extract constituents modulating THC and CBD effects. |
Abstract
We have shown previously that the plant cannabinoid cannabidiol (CBD) elevates intracellular calcium levels in both cultured hippocampal neurones and glia. Here, we investigated whether the main psychotropic constituent of cannabis, Delta(9)-tetrahydrocannabinol (THC) alone or in combination with other cannabis constituents can cause similar responses, and whether THC affects the responses induced by CBD. Our experiments were performed with 1 microM pure THC (pTHC), with 1 microM pure CBD (pCBD), with a high-THC, low CBD cannabis extract (eTHC), with a high-CBD, low THC cannabis extract (eCBD), with a mixture of eTHC and eCBD (THC:CBD=1:1) or with corresponding 'mock extracts' that contained only pTHC and pCBD mixed in the same proportion as in eTHC, eCBD or the 1:1 mixture of eTHC and eCBD. We detected significant differences in neurones both between the effects of pTHC and eTHC and between the effects of pCBD and eCBD. There were also differences between the Ca(2+) responses evoked in both neurones and glia by eTHC and mock eTHC, but not between eCBD and mock eCBD. A particularly striking observation was the much increased response size and maximal responder rates induced by the mixture of eTHC and eCBD than by the corresponding 1:1 mixture of pTHC and pCBD. Our data suggest that THC shares the ability of CBD to elevate Ca(2+) levels in neurones and glia, that THC and CBD interact synergistically and that the cannabis extracts have other constituents yet to be identified that can significantly modulate the ability of THC and CBD to raise Ca(2+) levels.
Comparable studies
Other preclinical and animal studies on cannabis, most cited first.
Citations in the library
Cited by 3
- The safety of studies with intravenous Δ⁹-tetrahydrocannabinol in humans, with case histories. Psychopharmacology February 2012
- The effect of Δ9-tetrahydrocannabinol on 5-HT3 receptors depends on the current density. Neuroscience November 24, 2010
- The acute effects of synthetic intravenous Delta9-tetrahydrocannabinol on psychosis, mood and cognitive functioning. Psychological Medicine October 2009