Estrogen Modulation of the Pronociceptive Effects of Serotonin on Female Rat Trigeminal Sensory Neurons is Timing- and Dosage-Dependent and Requires Estrogen Receptor Alpha

Since estrogen is a major hormone involved in multiple gene expression pathways in the cell, we wanted to determine the corresponding changes in trigeminal ganglia transcriptome of the E2-treated rats. Adult ovariectomized female rats were subcutaneneously implanted with either 5% (physiological level comparable to diestrus; 15-20 pg/ml; one capsule), 20% (physiological level comparable to proestrus; 40-60 pg/ml; 2 capsules of 10%), 40% (supraphysiological level; 2 capsules of 20%) E2, or control (2 capsules of 100% cholesterol) capsules. One week after implantation, nocifensive behaviors were recorded and trigeminal ganglia tissue was extracted. Total RNA was extracted from the right trigeminal ganglia (TG) tissue (n=3 per hormone treatment group) and sequenced [Novogene; sequencing lab at The University of California at Davis campus]