Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke

Summary

Mouse models have become increasingly popular in studies of behavioral neuroscience. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. This protocol describes the Pasta Matrix Reaching Task, which is a skilled motor task for use in mouse models of stroke.

Abstract

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. The present protocol describes a skilled motor task for use in mouse models of stroke. The Pasta Matrix Reaching Task functions as a versatile and sensitive behavioral assay that permits experimenters to collect accurate outcome data and manipulate limb use to mimic human clinical phenomena including compensatory strategies (i.e., learned non-use) and focused rehabilitative training. When combined with neuroanatomical tools, this task also permits researchers to explore the mechanisms that support behavioral recovery of function (or lack thereof) following stroke. The task is both simple and affordable to set up and conduct, offering a variety of training and testing options for numerous research questions concerning functional outcome following injury. Though the task has been applied to mouse models of stroke, it may also be beneficial in studies of functional outcome in other upper extremity injury models.

Introduction

Mouse models have become increasingly popular for experimental stroke research due in part to their convenience and affordability, as well as the availability of transgenic lines that are suitable for in vivo imaging among other applications. With this increased popularity in experimental models, the interest in developing sensitive behavioral assessments of functional outcome following injury has also increased ^1-7. The development of animal training protocols that mimic both rehabilitation and compensatory strategies used by human stroke survivors improves the ability to successfully translate findings from experimental animal studies to use in t....

Protocol

The following methods are in accordance with protocols approved by the University of Texas at Austin and Illinois Wesleyan Animal Care and Use Committees. It is recommended that researchers either wear gloves or take appropriate precautions (washing hands before and after) when engaging in behavioral training with any laboratory animal. Gloves must be worn when handling animals in preparation for and during surgery.

1. Habituation and Food Restriction

NOTE: As the PMRT is an appetitive task, it is beneficial to restrict the amount and timing of feeding prior to the onset of training in order to motivate the re....

Results

The results from PMRT analysis should include the number of pasta pieces broken and the pattern of successful reaches. Results from mice with sensorimotor cortical lesions indicate that ischemic insult affects both the number of successful reaches as well as physical reach patterns ^{3, 19}, as demonstrated in Figure 3A. Representative pattern changes can be observed in Figure 3B. The ability of the PMRT to mimic learned non-use effects in mice is demonstrated by impaired recover.......

Discussion

The PMRT represents a simple, quantitative way to assess skilled reaching performance in mice. Though time consuming, it is possible for previously inexperienced undergraduates to be trained to collect reliable and reproducible data with only a few training sessions. The task is sensitive enough to measure even slight changes in mouse motor skill performance following ischemic insult ^{3, 13, 15}, and a number of studies cite long-term deficits with a variety of training protocols ^{15, 20, 22}. Because i.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Reaching chamber			Reaching chambers are made in house with Plexiglas
Pasta matrix block			The Pasta matrix box is made in house using a heavy plastic block
Capellini pasta	DeCecco		DeCecco brand capellini pasta can be purchased in a grocery store or through an online retailer such as Amazon