Neurological diseases often result in a combination of motor and cognitive deficits. To gain a broader understanding of the underlying biological mechanisms and cognitive impairments, behavioral assessments are often combined with physiological readouts. This approach is highly relevant to therapeutic development. Below is an overview of commonly used assessments and the specific insights they provide.

Balance and Coordination Tests

1. Rotarod Test: The rotarod test assesses motor coordination and balance. Animals are placed on a rotating rod, and the rotation speed is gradually increased. Researchers record the latency to fall and the speed of rotation at the time of fall. This test is commonly used to detect subtle motor impairments or improvement following therapy.

2. Cylinder Test: This test is used to evaluate spontaneous forelimb use. Animals are placed into a transparent vertical cylinder, where they naturally rear and touch the walls for support. Observers record the number of wall contacts made with each forelimb to detect asymmetries, which can indicate motor deficits, especially after unilateral brain or spinal injuries.

3. Catwalk or Beam Walking Test: Animals are trained to walk across an elevated, narrow beam to reach a safe platform. This test challenges the animal’s ability to balance and coordinate fine motor movements. Performance is scored based latency to cross, and posture, helping assess subtle gait abnormalities.

Learning and Memory Tests

1. Morris Water Maze: A widely used test of spatial learning and memory, the Morris water maze involves placing animals in a circular pool filled with opaque water. A hidden platform is submerged just below the surface. Over repeated trials, the time it takes for the animal to locate the platform is recorded. Improved performance over time indicates learning, while retention trials assess memory.

2. Novel Object Recognition (NOR): This test assesses recognition memory. During the familiarization phase, animals are presented with two identical objects. Later, one object is replaced with a novel one. The amount of time the animal spends exploring the new object compared to the familiar one is interpreted as a measure of memory and cognitive processing.

Sensory and Motor Function Tests

1. Paw Adhesive Removal Test: This test evaluates sensory and sensorimotor integration. Adhesive dots are placed on each forepaw, and researchers record the time to first reaction (contact time) and the time it takes to remove the adhesive (removal time). Prolonged response or removal times may indicate sensory deficits or impaired motor coordination.

2. Grip Strength Test: Grip strength is used to assess forelimb muscle function. The animal is allowed to grasp a grid connected to a force sensor and is then gently pulled backward by the tail. The peak force exerted before release is measured, reflecting muscular strength and motor control.

3. Open Field Test: This assay measures general locomotor activity. Animals are placed in a contained, open arena, and their movements are tracked. While technically simple to perform, OFT is a highly versatile, informative technique for assessment of general activity levels, gross locomotor activity, and exploration habits. Additionally, enclosure may be modified to examine learning and memory functions (e.g. Novel Object Recognition).

Learn more about our behavioral assessments here.