Identifying CB₁ Receptors in the crayfish neuromuscular junction through immunofluorescence staining

Abstract

Cannabinoid receptors (CB₁) are present on presynaptic nerve terminals and alter release of neurotransmitters. Previous research asserts that CB₁ receptors are expressed in the majority of the animal kingdom, yet its presence in invertebrates have led to contradictory evidence supporting and disproving its existence (McPartland et al. 2006). Earlier, a study has found CB₁ receptors in the lizard nerve terminal (Newman et al. 2007). Our goal is to further this discussion by identifying whether CB₁ receptors are present in the crayfish extensor muscles presynaptic terminals. Our research design centers around the application of immunofluorescence staining through the use of two different antibodies that will result in two different stains (one for CB₁ receptors and the other for the presynaptic terminal). Our major results were the colocalization of anti-SNAP-25 and CB₁. This colocalization suggests that CB₁ receptors, first of all, do exist in the crayfish neuromuscular junction (NMJ), where endocannabinoids may play a functional role.