- Tabitha A. Iseger (1)
- Chris D. Schubart (1)
- Nick F. Ramsey (1)
- Matthijs G. Bossong (1)
- Hendrika H. Hell van (1)
- Matthias J.P. Osch van (1)
- Gerry Jager (1)
- J.M. Jansma (1)
- Evelien M. Olde de (1)
- Marco P. Boks (1)
- René S. Kahn (1)
- Wesley Saane van (1)
- Marion Sautier (1)
- Jay Whitehead (1)
Acute effects of ∆9-tetrahydrocannabinol (THC) on resting state brain function and their modulation by COMT genotype
Bossong, Matthijs G. ; Hell, Hendrika H. van; Schubart, Chris D. ; Saane, Wesley van; Iseger, Tabitha A. ; Jager, Gerry ; Osch, Matthias J.P. van; Jansma, J.M. ; Kahn, René S. ; Boks, Marco P. ; Ramsey, Nick F. - \ 2019
European Neuropsychopharmacology 29 (2019)6. - ISSN 0924-977X - p. 766 - 776.
Arterial spin labelling - Cannabis - Catechol-methyl-transferase (COMT) - Delta9-tetrahydrocannabinol (THC) - Resting state connectivity - Salience
Cannabis produces a broad range of acute, dose-dependent psychotropic effects. Only a limited number of neuroimaging studies have mapped these effects by examining the impact of cannabis on resting state brain neurophysiology. Moreover, how genetic variation influences the acute effects of cannabis on resting state brain function is unknown. Here we investigated the acute effects of ∆9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, on resting state brain neurophysiology, and their modulation by catechol-methyl-transferase (COMT) Val158Met genotype. Thirty-nine healthy volunteers participated in a pharmacological MRI study, where we applied Arterial Spin Labelling (ASL) to measure perfusion and functional MRI to assess resting state connectivity. THC increased perfusion in bilateral insula, medial superior frontal cortex, and left middle orbital frontal gyrus. This latter brain area showed significantly decreased connectivity with the precuneus after THC administration. THC effects on perfusion in the left insula were significantly related to subjective changes in perception and relaxation. These findings indicate that THC enhances metabolism and thus neural activity in the salience network. Furthermore, results suggest that recruitment of brain areas within this network is involved in the acute effects of THC. Resting state perfusion was modulated by COMT genotype, indicated by a significant interaction effect between drug and genotype on perfusion in the executive network, with increased perfusion after THC in Val/Met heterozygotes only. This finding suggests that prefrontal dopamine levels are involved in the susceptibility to acute effects of cannabis.
Comprehensiveness or implementation : Challenges in translating farm-level sustainability assessments into action for sustainable development
Olde, Evelien M. de; Sautier, Marion ; Whitehead, Jay - \ 2018
Ecological Indicators 85 (2018). - ISSN 1470-160X - p. 1107 - 1112.
Comprehensiveness continuum - Credibility - Farming - Learning tool - Legitimacy - Salience - Sustainability
Sustainability of food production has become the focus of many research projects and has gained a prominent position in the marketing of food products. To gain insight into the sustainability performance of farms, and ultimately support farmers in sustainable development, a large number of sustainability assessment tools have been developed. This expectation has made sustainability assessment tools increasingly popular to measure sustainability. The actual implementation of assessment tools in practice, and contribution of assessments to change, however, is being questioned. In fact, the movement towards ‘better’ sustainability assessment tools is being caught between two conflicting trends: the continual proliferation of sustainability assessment tools and the streamlining of market assurance programmes that give the impression of certainty in assessing sustainability. In this viewpoint article, we identify current limitations of sustainability assessments to catalyse change and formulate recommendations to the developers and users of such tools. We argue that challenges of implementation are, in part, related to the ambition of the assessment and their associated level of comprehensiveness. As a sustainability assessment becomes more comprehensive, and covers a wider range of issues or practices, the difficulty of implementing the sustainability assessment increases. We also highlight that the implementation challenge can be connected to the credibility, salience and legitimacy of knowledge produced by sustainability assessments. We conclude that increasing the transparency, harmonization, participation and sensitivity to farmer’ motivation in sustainability assessments is urgently needed to better link sustainability knowledge to action and overcome the current lock-in.