Table 3.

Prenatal Distribution (E15–E21) of the Small-Conductance Calcium-Activated Potassium Channel Subunit SK3¹

Brain region	E15	E17	E19	E21
Olfactory system
Olfactory bulb
Glomerular layer	np	np	++	+
Mitral cell layer	np	np	−	−
Internal granular layer	np	np	np	−
Accessory olfactory bulb	np	−	+++	++
Anterior olfactory nucleus	np	•	+++	++
Olfactory tubercle	np	np	+	+
Cerebral cortex
Piriform cortex	•	•	+	++
Primordial plexiform layer	+++	np	np	np
Cortical neuroepithelium	+	+	+	+
Molecular layer	np	−	−	−
Cortical plate	np	+++	−	−
Intermediate zone	np	+++	+	+
Subventricular zone	np	+++	+++	++
Hippocampal formation
Subicular neuroepithelium	+	++	np	np
Subiculum (or diff. field)	np	+++	++	++
Hippocampal neuroepithelium	+	+	np	np
Hippocampus (or diff. field)	+++	++	np	np
CA1	np	np	+++	++
CA3	np	np	+	+
Dentate gyrus granule cells	np	np	+	+
Basal ganglia
Striatum (or diff. field)	−	−	−	−
Thalamus
Anterior thalamus (or diff. field)	+	+++	+++	++
Posterior thalamus (or diff. field)	−	++	++	++
Intermediate thalamus (or diff. field)	+++	+++	+++	++
Trigeminal ganglion	+++	++	−	−
Inferior glossopharyngeal ganglion	•	•	−	−
Pons (or diff. field)	+	+++	++	•
Cerebellum
Cerebellar neuroepithelium	−	−	np	np
Cerebellum (or diff. field)	−	−	np	np
Deep nuclei	np	np	−	−
Purkinje cell layer	np	np	−	−
External germinal layer	np	•	−	−
Granule cell layer	np	np	−	−
Spinal cord	+++	+++	•	•
Dorsal root ganglia	++	++	•	•
Intestine	+++	+++	•	•

¹+++, strong; ++, moderate; +, weak; −, signals very low or below the threshold limit of detection; np, not present; •, not clearly identifiable; Diff. field, differentiating field.