Figure 3. Drd1 activation promotes glutamate-induced spinogenesis in mPFC pyramidal neurons through PKA signaling.

(A). Example 2PLSM images of de novo spinogenesis trials with ACSF or 1 μM SKF 81297. Red circles, uncaging sites. Black rectangle, close up images of local dendritic segments before and after glutamate uncaging. Scale bar, 2 μm.

(B). Probability of glutamate-evoked spinogenesis on deep layer mPFC neurons in brain slices with or without bath application of 1 μM SKF 81297. Slices were treated with 10 μM H-89 or collected from mice with genetic manipulation of GFP expressing pyramidal neurons (Drd1^ff or PKIα). Each small circle, aggregate probability of evoked spinogenesis from a single experiment. Large circles, group data. Paired two-tailed t test, ACSF vs SKF 81297, Control, p = 0.0007; Drd1^ff, p = 0.9249; H-89, p = 0.7351; PKIα, p = 0.4; n = 5 – 6 experiments/group.

(C). Top, colocalization of PKIα-mRuby2 in EGFP-expressing mPFC neurons. Bottom, close up images of EGFP and mRuby2 signals. Scale bar, 100 μm and 20 μm.

(D). Left, schematic illustrating glutamate-evoked spinogenesis assay in slices from mice pre-treated with ketamine (10 mg/kg, i.p.). Bottom, probability of glutamate-evoked spinogenesis on deep layer mPFC neurons in brain slices with or without bath application of 1 μM SKF 81297. Paired two-tailed t test, ACSF vs SKF 81297, p = 0.3745.

(E). Left, schematic illustrating triple viral transduction strategy for PKIα expression. Right, probability of glutamate-evoked spinogenesis in deep layer mPFC neurons in mice with or without PKIα expression, injected with ketamine (10 mg/kg, i.p.). Unpaired two-tailed t test, GFP vs GFP + PKIα, p = 0.0020.

(F). Schematic of simplified signaling pathways downstream of Drd1-PKA involved in actin remodeling in dendritic spines.

** p < 0.01, *** p < 0.001. Error bars reflect SEM.