Table 1.

Forward and reverse primer sequences along with corresponding amplicon size and accession numbers for real-time RT-PCR primers used in Experiment 1. Primers were designed to span an intron when possible.

	Primer	Sequence	Amplicon (bp)	Accession Number
Ligands	POMC	Forward 5′ TCC ATA GAC GTG TGG AGC TG 3′ Reverse 5′ ACG TAC TTC CGG GGA TTT TC 3′	173	NM_139326
	Preprodynorphin (PPD)	Forward 5′ GGG TTC GCT GGA TTC AAA TA 3′ Reverse 5′ TGT GTG GAG AGG GAC ACT CA 3′	83	NM_019374
	Preproenkephalin (PPE)	Forward 5′ AAA ATC TGG GAG ACC TGC AA 3′ Reverse 5′ CAT GAA ACC GCC ATA CCT CT 3′	197	NM_017139
Receptors	Mu Receptor (MOR)	Forward 5′ ATC GTC AAC GTC TGC AAC TG 3′ Reverse 5′ CCC TGC CTG TAT TTT GTG GT 3′	81	NM_001038598
	Kappa Receptor (KOR)	Forward 5′ CTT TGG CAG ATG CTT TG TT 3′ Reverse 5′ CAT CTC CAA AAG GCC AAG AA 3′	243	NM_017167
	Delta Receptor (DOR)	Forward 5′ AGC ATC TTC ACG CTC ACC AT 3′ Reverse 5′ CAA CAC CTG AAG CCA AGA CC 3′	136	NM_012617