Table 5.

Summary of experimental findings in P7 and P21 rats exposed to acute morphine, intermittent morphine, or continuous morphine.

	Postnatal day 7				Postnatal day 21
	Mechanical threshold	Thermal latency	WT	Behavior	Mechanical threshold	Thermal latency	WT	Behavior
Acute M exposure M w/drawal	Analgesia	Analgesia	o		Analgesia o	Analgesia o	o
Intermittent M exposure M w/drawal	Tolerance WH ↓ PWT	o o	--	↑ quiet ↓ behaviors ↑ behaviors	↓analgesia MA WH ↓ PWT	o TH WH ↓ PWL	o	↓ behaviors; ↑ behaviors;
Pump M exposure M w/drawal	Tolerance WH ↓ PWT	Tolerance	--	↑ quiet ↑ complex behaviors	Tolerance OA WH ↓ PWT	Tolerance	--	↑ behaviors no change
Pellet M exposure M w/drawal					Tolerance OA WH ↓ PWT	Tolerance WH ↓ PWL	--	↓ behaviors no change

WT = weight; WH = withdrawal associated hypersensitivity; OA = opioid-induced allodynia; MA = mechanical allodynia; TH = thermal hyperalgesia. Yellow highlight indicates age-specific responses. Blue highlights indicate modality specific responses. Green highlights indicate age and modality specific responses.