Activating mGlu2/3 receptors with the drug LY379268 reduces the behavioral effects of phencyclidine (PCP) in rats, and this effect is linked to changes in norepinephrine release. In rats undergoing brain microdialysis, LY379268 blocked PCP-induced hyperactivity for about three hours and transiently reduced PCP-induced dopamine release. PCP-induced norepinephrine release was reduced in a way that matched the timing of the behavioral reduction. Separately, the norepinephrine-related drugs clonidine (which reduces norepinephrine activity) blocked PCP behaviors, while reboxetine (which increases norepinephrine) worsened them. LY379268 reversed PCP effects even when reboxetine was present. These results suggest that mGlu2/3 receptor activation can normalize stress-related pathways affected by PCP.
Consciousness may arise from quantum processes in the brain's microtubules, where quantum superpositions in tubulin proteins self-collapse at a threshold linked to quantum gravity, producing discrete conscious events. This 'orchestrated objective reduction' (Orch OR) model, proposed by Roger Penrose and colleagues, suggests each collapse is a non-computable selection of spacetime geometry, coupling consciousness to fundamental physics. The theory aims to explain enigmatic features of consciousness that conventional neuron-based approaches fail to address, such as qualia. It posits that sequences of these events create a stream of consciousness, with microtubule-associated proteins tuning the quantum oscillations to orchestrate the process.