C - General Adult Motor Behavior

Objectives:

To describe posture and righting behaviors
To describe ground locomotion
To describe swimming behavior
To describe grooming behaviors
To describe exploratory behaviors

Introduction:

It is the role of the brain to produce behavior. While “behavior” can be broadly defined as “anything that the organism does”, the most obvious behaviors include a motor component. When trying to understand the neural basis of behavior, examining simple motor behaviors is a good place to start. The neural circuits underlying these behaviors are well described and highly conserved in vertebrates. Today you will examine a number of innate behaviors. Pay attention to the sequence of simple movements that make up the overall behaviors. The variety of behaviors examined in this lab is a good survey of the types of behaviors that rats would engage in on a daily basis. Observing the adult behavior today will help you evaluate the development of such behaviors in the later pup-development lab.

Procedure:

Preparation: Read chapters 11, 13, 14 and 16 in the Behavior of the Laboratory Rat book before this week’s lab.

Tests:

Posture and righting:

Trigeminal righting – righting of the head, triggered by the trigeminal nerve
- Place the rat on the table either on its back or its side making sure the head is touching the ground. Hold the animal there for a moment, then observe trigeminal righting when the head is released.
Body Tactile righting – body-on-head righting
- Righting/rotation that begins at the shoulders
- Place the rat on its side, without touching it’s head and without its head touching the table (head should be hanging off edge of the table), observe body-on-head righting.
Body Tactile righting – body-on-body righting –
- Righting/rotation that begins with the pelvis
- Place the rat on its side, hold one hand over the rat’s shoulders, the other hand over its pelvis, release the pelvis hand first, observe body-on-body righting.
Tactile/Proprioceptive Dynamic righting
- Rotation to face the direction of falling (falling while in contact with the ground)
- Hold the rat in the bipedal position, pull the rat backwards onto the ground, observe tactile/proprioceptive righting

Grooming

Place your rat in an empty cage and watch it for 5 minutes. Recorded the frequency of grooming behaviours. Note the sequence of body parts groomed.

Locomotion

Place your rat at one end of the walkway, and let it run to the other end. Video-taping this behaviour may simplify the analysis
Note the sequence of limb movements. Identify the stance and swing phase of movement for each limb.

Swimming

If you have a water maze available, prepare it with warm water and a visible platform. Place the rat in the water facing the platform
Observe the movements of its limbs and tail during the swim to the platform.
Removed the rat from the pool and dry it off with a towel.

Exploratory Behaviour

Place the rat in an open field for 5 minutes
Note the variety of behaviours exhibited, their sequence and durations. These include thigmotaxis (running along the wall), head movements, rearing, and different patterns of limb movements. Measure the amount of time spent in different regions of the open field. Attempt to determine if the animal has established a home-base.