TABLE 2.

Opioid Peptide Precursor Gene Expression in Neurons of the Hypothalamic Nuclei and Some Extrahypothalamic Structures¹

Region	Structure	Pre-POMC	Pre-PDYN	Pre-PENK
Chiasmatic	Supraoptic nucleus, dorsolateral	−	+	+
	Supraoptic nucleus, ventromedial	−	+	+
	Medial preoptic area	−	−	+++
	Intermediate nucleus	−	−	+++
	Suprachiasmatic nucleus	−	−	+++
	Paraventricular nucleus	−	+	+++
	Retrochiasmatic area	+++	++	++
Tuberal	Paraventricular nucleus	−	++	++
	Dorsomedial nucleus	−	+++	+
	Ventromedial nucleus	+	++	+++
	Premammillary nucleus	−	+++	+
	Lateral tuberal nucleus	−	−	+
	Tuberomammillary nucleus	−	+	+
	Infundibular nucleus	+++	−	+++
Mammillary	Mammillary body	−	−	−
	Posterior hypothalamus	−	+++	++
	Paraventricular nucleus	−	++	++
Extrahypothalamic	Amygdala, central nucleus	−	−	+++
	Amygdala, cortical nucleus	−	+++	−
	Bed nucleus of the stria terminalis	−	++	+++
	Nucleus basalis of Meynert	−	−	+
	Nucleus accumbens	−	+++	+
	Putamen	−	+	+++
	Caudate nucleus	−	++	+
	Globus pallidus	−	−	++
	Parolfactory gyrus	−	+	+
	Zona incerta	−	++	++

¹−, Opioid peptide precursor mRNA-containing cells were absent (0% of the whole neuronal population); +, only a few cells that express the opioid peptide precursor gene were present in the structure (1–10%); ++, cells that express the opioid peptide precursor gene were present in moderate numbers in the nucleus (10–60%); +++, cells that express the opioid peptide precursor gene were very abundant in the nucleus (60–100%).