Fig. 1.
A schema depicting the possible relationships among NPS, orexins, substance P, mGlu5R and endocannabinoid (2-AG) during SIA, based on the available literature. The cascades occurring in the locus coeruleus (LC)/ parabrachial nucleus (PBN), lateral hypothalamus (LH) and periaqueductal gray (PAG) during stress or exposing to NPS (purple), orexins (red) or substance P (blue) are depicted in the right box. The findings that have been reported are shown by solid lines with the numbers of referred literatures. To fulfil our hypothesis, the links that have to be proven are now established in this study, which are denoted by broken lines marked with [★]. The images of mouse brain and neurons are adapted from Illustration Toolkit Neuroscience by Motifolio. PN: projection neuron; SubP: substance P; Glu: glutamate