Fig. 5: Pharmacological manipulation of galanin receptors in the infant thalamus affects whisker-dependent behavioral outcomes.

a Distribution of galanin⁺ neurons and VGLUT2⁺ afferents in the ventrobasal thalamus (VB) on postnatal day (P)10. M617, a Gal₁R-selective agonist, and M40, a non-selective antagonist, were applied locally on P5. Open arrowheads point to galanin⁺ perikarya. Range indicators to the left mark the altered density of VGLUT2⁺ afferents. Photomicrographs are representative of each experimental group in b₁. b Gal₁R modulation affected the density of glutamatergic (VGLUT2⁺) synapses in the VB. Note the opposing effects of M617 and M40. b₁ Morphometric data were collected from n = 3 mice/group, and statistically assessed using two-tailed unpaired Student’s t-test (treatment vs. control). M617 significantly increased synapse density (**p = 0.0014). c Gal₁R manipulation significantly increased exploratory behavior in infant mice on P10 (n = 8 mice/group; male (black) and female (red) data were disaggregated as shown). Data were analyzed by Student’s t-test (two-tailed, unpaired): *p = 0.023 (control vs. M617), **p = 0.001 (control vs. M40). However, M617 and M40 had opposite effects after whisker removal, recapitulating RNAi-induced outcomes (n = 5 mice/group; *p = 0.015 (M617 vs. M40); two-tailed unpaired Student’s t-test). d The effect of acute pharmacological manipulation of Gal₁Rs in the VB was transient, as assessed on P45 (n = 3 mice/group). Data in bar graphs were expressed as means ± sem throughout. Scale bars = 100 µm a, 10 µm b.