Table 1.

Characteristics of the different routes of ethanol administration in mice.

Administration route	Characteristics	Reached BAC	Advantages	Disadvantages
Voluntary ethanol feeding	Oral, self-administration. Pre-gestational alcohol consumption is usually introduced (36). Sometimes, ethanol is added to flavored liquid nutritional formulas (Liquid-diet or Sustacal) to allow easy self-administration (37, 38). 10–20% (vol/vol) ethanol solution (36). Possibility of isovolumic and isocaloric pair-fed diet (e.g., maltose-dextrin) in controls (28). Drinking in the dark (DID) procedure mimics binge-like pattern (39).	50–100 mg/dL when ethanol intake is 1–2 g/Kg [10% (vol/vol) ethanol solution]	Prevent the stress caused by other invasive methods. Safe technique. Easy to carry out. Gradual BAC increase. Low, stable BAC levels. Used prenatally.	Lower ethanol BAC achieved compared to other administration routes. Not useful for binge drinking pattern. Difficult control of dose and timing. No proper control of dose in breastfeeding pups. Not recommended postnatally. Lower BAC achieved if saccharin or a sucrose-sweetened solution is added to the alcohol.
Intragastric gavage	Administration of ethanol into the stomach using a gavage needle. Administered volumes <2 mL/100 Kg body weight (40). Allowed alcohol concentration <31.5% (vol/vol) (40). Ethanol dose 2–6 g/Kg/day (28). Ethanol vehicle (water, saline solution, or nutritional formula) (28).	250–300 mg/dL (60 min) for administration doses of 3.8 g/Kg [21% (wt./vol) ethanol solution]	Useful for binge drinking pattern. Accurate control of dose and timing. Reliable high BAC. Useful for pre- and postnatal administration.	Inhibition of suckling behavior in neonates. Stressful procedure for animals. Invasive procedure.
Inhalation	Inhalation chamber filled with ethanol vapor (41). Sometimes, administration of pyrazole to obtain stable BACs (32, 42).	150–250 mg/dl when volatized ethanol (ethanol 95%) is delivered to the chamber at a rate of 10 l/min	Reliable high BAC. Not a stressful technique for animals. Time and labor efficient. Useful for pre- and postnatal administration. Higher BACs in neonates compared to mothers.	Does not mimic the routes of intake in humans. Special equipment required. Interindividual variations.
Intraperitoneal injection	Ethanol solution injection in intraperitoneal space (43). Single or multiple doses for several days during pregnancy.	350–400 mg/dL (60 min) for administration doses of 3.8 g/Kg [21% (wt./vol) ethanol solution]	Rapid increase in BAC. Time efficient. Useful for pre- and postnatal administration. Useful for binge drinking pattern.	Handling-induced stress. Different intake routes in humans. This administration route produces higher BAC in fetuses than other routes using the same PAE. Higher incidence of malformations when used during first trimester equivalent.
Artificial rearing	Intragastric gavage ethanol discharge in pups while being kept in a special setting to mimic maternal environment (29, 34, 44). Placement of gastrostomy catheters.	150 mg/Kg when ethanol solution of 2,5 g/Kg is administered or 420 mg/Kg when ethanol solution of 7,5 g/Kg is administered*	Accurate control of dose and timing. Useful for postnatal administration. Mimics human third trimester.	Invasive and expensive technique. Social factors removed due to isolation of pups.

^*Data obtained from experiments with rats (no available data for mice). BAC, blood alcohol concentration; Vol, volume; Wt, weight.