It therefore became of interest to study the FGF2 and 5-HT1A agonist regulation of the FGFR1-5-HT1A heterocomplexes in the hippocampus and dorsal raphe in a genetic rat model of depression (FSL) vs. the control SD strain using the in situ PLA. The gene discussed is FGFR1; the disease is depressive disorder.