Figure 8.
Suckling causes dissociation of Gαq/11 from Gβ subunits in confocal images. A, Effects of suckling on spatial distribution of Gαq/11 subunits. A1, A2, Exemplary images from nonsuckling lactating rats (A1) and suckling rats (A2). They show, from left to right, nuclei (Hoechst, in gray), Gαq/11 subunits (in green), Gβ subunits (in red), OT–NP (in blue), and the merges of different channels. White arrows indicate that quantification of immunointensity was from OT neurons that were scanned through the middle planes of their nuclei. Asterisks indicate nuclei of nonmagnocellular cells (i.e., putative astrocytes). Merged panel, Letters (a–d) in white frames show the sources of the magnified images in A3. Note that dominant Gβ expression occurred in both OT neurons and the astrocytes after suckling stimuli. Note that in the nuclei and cytosol of astrocytes, suckling caused Gβ increases by 22 ± 7.2 and 45.1 ± 11.3%, whereas Gαq/11 decreased by 22.2 ± 8.9 and 14.8 ± 6.7% of nonsuckling control (n = 10; p < 0.05–0.01 in all groups), respectively. For a better demonstration of the spatial distribution of the two G-protein subunits, sequential staining of Gαq/11 and Gβ was performed (i.e., after staining the first primary antibody with Alexa Fluor 647-labeled donkey anti-rabbit antibody, the second primary antibody was added and stained with Alexa Fluor 488-labeled donkey anti-rabbit antibody). B, Summary graphs based on 20 SONs from five pairs of rats. B1, Relative intensity changes in different loci of OT neurons and whole frame of the images from suckling and nonsuckling rats. B2, Intensity changes of β subunits relative to Gαq/11 subunits in both nonsuckling and suckling rats. †p < 0.05 and ††p < 0.01 with χ2 test; *p < 0.05 and **p < 0.01 with paired t test.