Crabbe5 project protocol

Drug study: Assessment of ethanol sensitivity and intoxication using the parallel rod floor apparatus in 8 inbred strains of mice   (2005)

Crabbe JC
With: Kamens HM, Phillips TJ, Holstein SE




Crabbe5 Protocol

Project protocol — Contents
Workflow, sampling, and experimental treatment
Equipment
Reagents,supplies, and solutions
Procedure: Parallel rod floor test for motor incoordination
Data
References



Workflow, sampling, and experimental treatment

Strains were serially tested on four floor types (see details below).  Animals were randomized into two groups per strain. 

Group 1 floor order: E, A, D, B

Group 2 floor order: A, E, D, B

Each mouse was tested before (saline control) and after EtOH treatment.

Each mouse was tested on four platforms of the parallel rod floor apparatus (see Equipment below) on a rotating 3-day injection schedule.  Mice were undisturbed for six days between platforms. 

Workflow

Day Injection Tested Data collected
1
Saline
Yes
Yes
2
Saline
Yes
Yes
3
EtOH
Yes
Yes
4-9
None *
No
No
* Recovery period before next platform

Treatment

Dose 2g EtOH per kg body weight [g/kg]
Delivery intraperitoneal injection (i.p.)

Equipment

• Parallel rod floor apparatus is described in detail in Crabbe et al., 2003 and more information in Kamens et al., 2005. 

Briefly, a clear acrylic box sits is placed on top of a parallel rod floor which is 1 cm above a base plate.  The apparatus is set inside an activity monitor.  The activity monitor is housed in a sound-insulated black acrylic chamber equipped with fluorescent lighting and a ventilating fan.  Errors are recorded by an Apple IIE computer when a paw slips through the rods and completes an electrical circuit with the base plate.  The activity monitor records horizontal distance traveled (detected by photocell beam breaks).

Parallel rod floor configurations

Floor * (apparatus) Rod diameter (mm) Inter-rod distance (mm)
A
1.6
4
B
1.6
6
D
3.2
6
E
4.8
6
* A, B, D, E are described in Kamens et al., 2005.
Configuration C was not used for testing.

• AccuScan Activity Monitor, Columbus OH, USA

Reagents, supplies, solutions

  • Test agent: ethanol (EtOH), Pharmoco Inc, Brookfield CT, USA;
  • EtOH solution prepared at 20% v/v in saline
  • Saline (physiological saline): 0.9%, Baxter Healthcare Corp, Deerfield IL, USA
  • Isopropyl alcohol: 10% for wipe downs between testsAcclimation to test conditions

Acclimation

Mice are acclimated to room environment 45-60 min before testing.

Procedure: Parallel rod floor test for motor incoordination

a. Randomly selected mice are i.p. injected with saline or EtOH.
b. Each mouse is immediately positioned in the center of the parallel rod floor apparatus (see Equipment above for details), and testing begins.
c. Mice are monitored and data collected over 15 min of testing.
d. The apparatus is cleared and wiped with 10% isopropyl alcohol after each test.

Data collected by investigator

Distance traveled and number of paw slips (errors)

Definitions & formulas

Motor incoordination (err) = (#errors / distance traveled) x 100