G1 - Movement Disorders: Stroke

Objectives:

• To observe a pial strip surgery as a model of stroke.

• To test rats with a pial strip of the caudal forelimb area of the motor cortex on a number of behavioral tests.

• To write a full manuscript-style lab report comparing the effects of the stroke on the various behaviors.

Introduction:

Stoke is a leading cause of death among adults. While many patients survive a stroke, they are frequently left severely impaired. Since there is little in the way of regeneration following a stroke, behaviors controlled by the area of brain injured by the stroke must be re-learned. This involves surviving areas of the brain acquiring control of the affected behavior, or the learning of new compensatory behaviors to replace the impaired function. Development of therapies that promote these sorts of brain plasticity could enhance both the speed and extent of recovery (Whishaw et al., 2008). The development of potential therapies depends on useful models of stroke in animals, particularly those that mimic the types of strokes experienced by people. There are a number of animal models of stroke, each with their own advantages and disadvantages (Howells et al., 2010).

Procedure:

Preparation: Read Kolb (2005) before the lab. Your TA will prepare the test animals ahead of time by performing the pial strip surgeries (See Appendices B and C for the procedure). Depending on local regulations, you may be invited to observe and/or participate. The same male rats used in Laboratory Exercises C and D will be used for the surgeries, allowing you to compare the behaviors both before and after the stroke. Some behaviors will be more affected than others.

Testing: Follow the procedures outlined in Laboratory Exercises C and D with your rat. Submit the data to your TA who will collate the data from all groups. This complete data-set will be used for your write-up.

Follow-up: In any surgical intervention, histological confirmation of the effectiveness to the surgery is important. Discuss with your TA opportunities for learning about histological procedures (perfusion, tissue slicing and staining, microscopy) that may be available. For this study, perfusion with formalin, tissue sectioning and a nissl stain such as cresyl violet would be appropriate histological procedures.

References:

Howells DW, Porritt MJ, Rewell SS, O'Collins V, Sena ES, van der Worp HB, Traystman RJ, Macleod MR (2010) Different strokes for different folks: the rich diversity of animal models of focal cerebral ischemia. J Cereb Blood Flow Metab, 30(8):1412-31.

Kolb B (2005) Neurological Models. In: IQ Whishaw and B Kolb (Eds), The behavior of the Laboratory rat: A handbook with tests. Oxford University Press: Toronto.

Whishaw IQ, Alaverdashvili M, Kolb B (2008) The problem of relating plasticity and skilled reaching after motor cortex stroke in the rat. Behav Brain Res, 192(1):124-36.