Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/9/1996
Publication Date: N/A
Technical Abstract: Pigs possess cannabinoid receptors in their brain. They also synthesize anandamide, an endogenous ligand for this receptor. We have previously demonstrated that pharmacological activation of this receptor with cannabinoid compounds results in behavioral hypomotility in pigs. We hypothesized that the cannabinoid pathway may be involved with stress-coping mechanisms in the pig. Tame, mature boars (n=10) were obtained. Five were quickly rendered unconscious with sodium pentobarbital, and hypothalamic tissue was collected and frozen (Control). The other five pigs (Trt) were hurriedly walked through a series of gates and pens for 15 min. Then, for an additional 15 min, each Trt boar was put into a pen with a strange boar where aggressive behavior was displayed. Hypothalamic tissue was then collected as above. Total RNA was extracted and quantitative RT-PCR was performed to reflect relative amounts of cannabinoid receptor mRNA in each sample. Pigs experiencing the handling and mixing stress had 42% more (P<.05) cannabinoid receptor mRNA (RT-PCR product) when compared to controls. As an additional control, the abundance of LHRH mRNA was examined in all samples. No differences in expression of this hypothalamic neuropeptide gene were observed between the two groups. These results demonstrate that certain stressors can induce specific changes in the cannabinoid pathway.