Table 4.

Injection parameters of H129-dTK-tdT monosynaptic tracer

Animal	Brain region	Helper AAV			H129-dTK-tdT			Perfusion time (day)b
		AAVs (1 × 1012 vg/mL)	Vol.a (μL)	Inject. time	Dose (pfu)	Vol.a (μL)	Inject. time	For starter neuron	For postsynaptic neuron
C57BL/6	MOB [16]	AAV2/9-TK-GFP	0.45	Day 1	2.00 × 105	0.40	Day 22	Day 25	Day 29
C57BL/6	αBLA [22]	AAV2/9-TK-GFP	0.20	Day 1	5.00 × 104	0.10	Day 22	Day 25	Day 27
C57BL/6	VPM [16]	AAV2/9-TK-GFP	0.20	Day 1	1.00 × 105	0.20	Day 22	Day 25	Day 32
C57BL/6	LGN [16]	AAV2/9-TK-GFP	0.20	Day 1	1.00 × 105	0.20	Day 22	Day 25	Day 32
C57BL/6	pBLA [22]	AAV2/9-TK-GFP	0.20	Day 1	5.00 × 104	0.10	Day 22	Day 25	Day 27
PV-Cre	nRT [16]	AAV2/9-DIO-TK-GFP	0.35	Day 1	1.25 × 105	0.25	Day 22	Day 25	Day 32
DAT-Cre	VTA [16]	AAV2/9-DIO-TK-GFP	0.35	Day 1	1.25 × 105	0.25	Day 22	Day 25	Day 32

^aInjected volume should not exceed 0.5 μL for brain regions.

^bExtending the waiting time before perfusion normally results in higher labeling intensity and more labeled postsynaptic neurons. However, the starter neurons are also more severely damaged due to H129-dTK-tdT toxicity when conditional replication occurs.