4-Aminocyclopentane-1,3-diols as platforms for diversity: synthesis of anandamide analogs.

Starting from cyclopentadiene, two racemic mixtures of 4-aminocyclopentane-1,3-diols were prepared in 8 steps and characterized. Structure determination proved the anticipated trans-orientation of the two oxygen atoms with respect to the plane of the ring. The fragment-like new compounds are small and hydrophilic, devoid of rotatable bonds, and offer stereochemically defined attachment points for substituents.

Effects of acute and repeated restraint stress on endocannabinoid content in the amygdala, ventral striatum, and medial prefrontal cortex in mice.

Endocannabinoid signaling has been implicated in habituation to repeated stress. The hypothesis that repeated exposures to stress alters endocannabinoid signaling in the limbic circuit was tested by restraining male mice for 30 min/day for 1, 7, or 10 days and measuring brain endocannabinoid content. Amygdalar N-arachidonylethanolamine was decreased after 1, 7, and 10 restraint episodes; 2-arachidonylglycerol was increased after the 10th restraint.

Accumulation of anandamide: evidence for cellular diversity.

The endocannabinoid N-arachidonylethanolamine (AEA) is accumulated by many cell types, but the mechanisms are unknown. Data from several laboratories are consistent with the hypothesis that the accumulation of AEA occurs via the action of a transmembrane carrier that binds and transports AEA. However, other data suggest that AEA is sufficiently lipophilic to transverse plasma membranes by passive diffusion and will accumulate if it is catabolized intracellularly.

D2 dopamine receptors modulate Galpha-subunit coupling of the CB1 cannabinoid receptor.

CB(1) cannabinoid (CB(1)) and D(2) dopamine (D(2)) receptors are known to couple to the G protein Galpha(i/o). It has been reported that concurrent activation of D(2) receptors and CB(1) receptors, in primary striatal neuronal culture, promotes functional CB(1) receptor coupling to Galpha(s) resulting in elevations in intracellular cyclic AMP levels. We now report that in the absence of D(2) receptors, acute activation of CB(1) receptors inhibits cyclic AMP accumulation, whereas the presence of D(2) receptors promotes CB(1)-stimulated cAMP accumulation, presumably through Galpha(s).

Cellular accumulation of anandamide: consensus and controversy.

The endocannabinoids N-arachidonylethanolamine (AEA or anandamide) and 2-arachidonylglycerol (2-AG) are hypothesized to function in the brain as interneuronal signaling molecules. Prevailing models of the actions of these molecules require that they traverse cellular plasma membranes twice; first, following cellular synthesis and second, prior to enzymatic hydrolysis. The transmembrane movement of AEA has been studied in multiple laboratories with a primary focus on its cellular accumulation following extracellular administration.