Figure 4
GSNO only marginally affect opiate related receptor (ORL1), μ opioid receptor (MOR) and adenosine A 1 (Ado A 1 ) receptors signaling in brain sections. [35S]GTPγS autoradiography was conducted using a 3-step protocol with adenosine deaminase (ADA, 1 U/ml) present throughout steps 2 and 3, as detailed in the Methods section. Where indicated, GSNO (1 mM) was present for 60 min during the GDP loading (step 2). Protease inhibitor cocktail was included in step 2 for brain sections used for testing ORL1 and MOR responses. Receptor agonists nociceptin (ORL1), DAMGO (MOR), and 2-chloroadenosine (2ClAdo) (adenosine A1 receptor) were present at submaximal concentrations during step 3. Note wide distribution of nociceptin-responsive brain regions, including the cerebral cortex (Cx). Note also robust response to DAMGO in the MOR-enriched striatal patches (Sp), as well as the relatively GSNO-resistant, and widely distributed adenosine A1 receptor-dependent signal throughout the sagittal plane. Scale bar = 2 mm. For quantitative data on selected brain regions, see Supplementary Table 2 in additional file 1.