Part III: Principal component analysis: bridging the gap between strain, sex and drug effects.
R J Keeley, R J McDonald
Behavioural Brain Research July 15, 2015 DOI: 10.1016/j.bbr.2015.03.027 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Secondary analysis of experimental animal data using principal component analysis Peer reviewed |
|---|---|
| Population | Adolescent male and female Long-Evans and Wistar rats exposed to THC and tested as adults |
| Intervention | THC |
| Measures | skilled reaching task, Morris water task, discriminative fear-conditioning to context task, elevated plus maze task, conditioned place preference task to a low dose of amphetamine, volumetric estimates of brain volumes, cfos activation |
| Topics | Cannabis |
| Keywords | Adolescence Principal component analysis Rat strain Sex |
| Key findings | Early life experience accounted for a large proportion of variance across behavioral datasets, though its relative contribution varied by task, while THC exposure accounted for a very small proportion of variance across all behavioral tasks. The authors conclude that THC exposure had a negligible effect on variance in the dataset. |
Abstract
Previous work has identified the adolescent period as particularly sensitive to the short- and long-term effects of marijuana and its main psychoactive component Δ9-tetrahydrocannabinol (THC). However, other studies have identified certain backgrounds as more sensitive than others, including the sex of the individual or the strain of the rat used. Further, the effects of THC may be specific to certain behavioural tasks (e.g. measures of anxiety), and the consequences of THC are not seen equally across all behavioural measures. Here, data obtained from adolescent male and female Long-Evans and Wistar rats exposed to THC and tested as adults, which, using standard ANOVA testing, showed strain- and sex-specific effects of THC, was analyzed using principal component analysis (PCA). PCA allowed for the examination of the relative contribution of our variables of interest to the variance in the data obtained from multiple behavioural tasks, including the skilled reaching task, the Morris water task, the discriminative fear-conditioning to context task, the elevated plus maze task and the conditioned place preference task to a low dose of amphetamine, as well as volumetric estimates of brain volumes and cfos activation. We observed that early life experience accounted for a large proportion of variance across data sets, although its relative contribution varied across tasks. Additionally, THC accounted for a very small proportion of the variance across all behavioural tasks. We demonstrate here that by using PCA, we were able to describe the main variables of interest and demonstrate that THC exposure had a negligible effect on the variance in the data set.
Comparable studies
Other preclinical and animal studies on cannabis, most cited first.
Citations in the library
Cites 9
- Cannabinoid modulation of drug reward and the implications of marijuana legalization. Brain Research December 2, 2015
- Part II: Strain- and sex-specific effects of adolescent exposure to THC on adult brain and behaviour: Variants of learning, anxiety and volumetric estimates. Behavioural Brain Research July 15, 2015
- Adolescent exposure to THC in female rats disrupts developmental changes in the prefrontal cortex. Neurobiology of Disease 2015
- Changes in hippocampal morphology and neuroplasticity induced by adolescent THC treatment are associated with cognitive impairment in adulthood. Hippocampus August 2009
- The depressive phenotype induced in adult female rats by adolescent exposure to THC is associated with cognitive impairment and altered neuroplasticity in the prefrontal cortex. Neurotoxicity Research May 2009
and 4 more in the library