The document summarizes an experiment that tested the effects of ethanol on rat behavior in the Porsolt forced swim test, an animal model of depression. Rats were given either ethanol or a vehicle control before being placed in water, and their latency to become immobile and total immobility time were measured. Rats that received ethanol showed significantly less immobility time and lower latency to become immobile compared to control rats, indicating ethanol has an antidepressant-like effect in this test.

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Expt No- 9 Date- 24-9-2019
Porsolt's Forced Swim Test (Animal Model of Depression)
Aim- To study effect of ethanol on duration of immobility in Porsolt's forced swim test in rats.
Theory- Ethanol shares several pharmacological effects including sedative/hypnotic/ motor
inco-ordinating, anxiolytic and anticonvulsant actions with GABAA receptor modulators like
benzodiazepines and barbiturates. Acute administration of ethanol exhibits antidepressant like
action which is potentiated by muscimol a GABAA receptor agonist and blocked by bicuculline,
a GABAA receptor antagonist.
Requirements- Rats, Ethanol, glass cylinder.
Procedure- The rats were subjected to pre-test session for 15min in a glass cylinder (21 x 12 x
12cm) containing water up to 9cm maintained at 25 + 2oC. 24h later, the animals were treated
intraperitoneally either with vehicle or ethanol (2.5g/kg of 20% v/v) and each animal was again
forced to swim in similar environment for a period of 6min in a test session and immobility time
was recorded. The rat was judged immobile if it ceased struggling and remained floating

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motionless in water making only those movements necessary to keep its head above water.
Reduction in the duration of immobility was considered as antidepressant like effect.
Observation table- Effect of ethanol on latency to immobility and duration of immobility in
forced swim test in rats-
Gp I- Normal vehicle
SN Wt in gm Treatment – water 2ml/kg bw ip Latency to immobility in sec Duration of immobility in sec
1 129 0.25 300 342
2 132 0.26 300 345
3 131 0.26 290 341
4 130 0.26 310 348
5 129 0.25 295 339
6 128 0.25 305 342
SD 300+ 7.07 342.83+ 3.19
Gp II-Ethanol treated-The density of 20% ethanol is 0.969g/ml 2.5g = 2.58ml (2.58ml/kg bw ip)
SN Wt in gm Treatment -Ethanol 2.58ml/kg
20%v/v ip
Latency to immobility in sec Duration of immobility in sec
1 118 0.30 175 300
2 130 0.33 180 240
3 119 0.30 176 296
4 129 0.33 179 242
5 117 0.30 182 302
6 131 0.33 178 240
SD 178.33 + 2.58*** 270+ 32.20 ***
Statistical analysis was done by student t test. The latency to immobility shown by group II rats
( p value less than 0.0001) was considered to be extremely statistically significant (178.33 +
2.58) when it is compared to group I rats (300+ 7.07 sec),
The duration of immobility shown by group II rats ( p value equals to 0.0003) was considered to
be extremely statistically significant (270+ 32.20) when it is compared to group I rats (342.83+
3.19).
Report- The present results provide evidence for an antidepressant-like action of ethanol as the
ethanol ingested rats were shown a significant decrease in the latency of immobility and
duration of immobility when compared to vehicle treated normal rats (group I).