SENSORIMOTOR AND COORDINATION
Assessment of sensorimotor and coordination is an important part of the behavioral studies. Indeed, behaviors result from the integration of environmental sensory stimuli and their conversion within the central nervous system into motor commands.
The notion of brain-body-environment interaction refers to causal effects. Simplistically, sensory inputs causally affect motor outputs, and these motor outputs in turn causally affect sensory inputs. Such “perception-action loops” is crucial to any biological organism or artificial system that possesses the ability to react to the environment. Integration of the sensory perception and motor output occurs in the cerebellum and the basal ganglia. Both structures project by many neural pathways to the motor cortex, which commands movements to the muscles, and to the spinocerebellar tract, which provides feedback on the position of the body in space (proprioception). Consequently, cerebellum and basal ganglia are responsible of smooth, coordinated movements and a disturbance of either system will show up as disorders in fine movements, equilibrium, posture, and motor learning, as observed in Parkinson’s or Huntington’s diseases.
Studying neurobiological mechanisms of these common diseases is therefore essential to find efficient therapeutic strategies. To do so, various behavioral tasks have been developed in laboratory rodent models and... [more]
Assessment of sensorimotor and coordination is an important part of the behavioral studies. Indeed, behaviors result from the integration of environmental sensory stimuli and their conversion within the central nervous system into motor commands.
The notion of brain-body-environment interaction refers to causal effects. Simplistically, sensory inputs causally affect motor outputs, and these motor outputs in turn causally affect sensory inputs. Such “perception-action loops” is crucial to any biological organism or artificial system that possesses the ability to react to the environment. Integration of the sensory perception and motor output occurs in the cerebellum and the basal ganglia. Both structures project by many neural pathways to the motor cortex, which commands movements to the muscles, and to the spinocerebellar tract, which provides feedback on the position of the body in space (proprioception). Consequently, cerebellum and basal ganglia are responsible of smooth, coordinated movements and a disturbance of either system will show up as disorders in fine movements, equilibrium, posture, and motor learning, as observed in Parkinson’s or Huntington’s diseases.
Studying neurobiological mechanisms of these common diseases is therefore essential to find efficient therapeutic strategies. To do so, various behavioral tasks have been developed in laboratory rodent models and are largely validated. Moreover, because behavioral experiments typically measure motor coordinated responses to sensory information, assessment of these abilities is required for the interpretation of results of experiments designed to assess other neurobiological processes.
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EXPERIMENTAL TESTS
Rotarod test
The rotarod is a standard test of motor coordination, balance and fatigue in rodents. Basically, the animals are placed on rotating lanes rotating at different speeds or under continuous acceleration, and the time latency to fall from the rotarod is recorded.
- Easy-to-perform test
- Allows multi-animals sessions
- Allows evolution curves of performance
- Sensitive for both rats and mice
- Poor in detecting minor deficits or improvements in coordination
- Needs habituation sessions
- Motor phenotyping
- Drug screening
- Parkinson disease
- Huntington disease
- Alcohol dependence
- Aging
Grip strength test
The purpose of this test is to evaluate the limb motor or muscular functions in rodents. It represents a complementary test to the rotarod test. Basically, subjects are pulled by the tail while they are allowed to grasp a grid or a bar. The maximal force applied to the grid or the bar just before they lose grip form is recorded.
- Easy and rapid test
- Sensitive for both rats and mice
- High variability in the response
- Habituation to the response inducing a loss of motivation when measurements are performed at short interval
- Influenced by user handling (need training)
- Neuromuscular diseases
- Phenotyping
- Drug screening
- Parkinson disease
- Huntington disease
- Aging
Startle response to acoustic and tactile stimulus
The startle response is a brainstem reflex elicited by an unexpected acoustic or tactile stimulus. The evaluation of startle reflex response (and its habituation) to acoustic or tactile stimulus of different intensities is widely used for the detection of sensorimotor gating and hearing deficiencies in phenotyping evaluations.
- Neurological phenotyping for motor and sensory capabilities
- Objective measurement: automated detection of startle reflex
- Sensitive for both rats and mice
- Restraint conditions (habituation phase needed)
- Non-specific influence of attention processes
- Neurological phenotyping
- Hyperekplexia
- Auditory deficits
- Parkinson disease
- Huntington disease
- Schizophrenia
Prepulse inhibition of startle reflex
Prepulse Inhibition (PPI) paradigm is commonly used to evaluate sensorimotor gating as well as attentional processes involved in information selection processing. The startle response is a brainstem reflex elicited by an unexpected acoustic or tactile stimulus. In the prepulse inhibition test, sensorimotor gating is assessed by evaluating the characteristics of the innate reduction of the startle reflex induced by a weak prestimulus. This test measures pre-attentive processes that operate outside of conscious awareness and is widely used in animal models of diseases marked by an inability to inhibit, or "gate" irrelevant information in sensory, motor, or cognitive domains.
- Reproduces the same paradigm used in humans to detect attentional and sensorimotor gating disorders
- Objective measurement: automated detection of startle reflex
- Sensitive for both rats and mice
- Restraint conditions (habituation phase needed)
- Influenced by non-specific effects on sensorimotor gating
- Drug screening
- Phenotyping
- Attention-Deficit Hyperactivity Disorder (ADHD)
- Schizophrenia
- Autism
- Obsessive compulsive disorder
- Huntington disease
- Nocturnal enuresis
- Tourette syndrome
Rotameter test
Rotational behavior has proved a popular technique for screening the behavioral effects of a wide variety of lesions, drugs, and other experimental manipulations on the brain of rodents. This test is widely carried out in experiments using animal models of Parkinson disease with unilateral lesions in the dopaminergic nigrostriatal system in which the number and direction of animal rotations in quantified after apormorphine treatment.
- Rapid and easy-to-do test
- Can be entirely automated
- Drug screening
- Parkinson disease
- Rotameter system with Rotation Sensor, Rat or Mouse Harness, Bowl or Cylinder container, Individual counter
- Rotameter system with Rotation Sensor, Rat or Mouse Harness, Bowl or Cylinder container, Multicounter, SeDaCom software
- Bowl or Cylinder container, SMART video tracking (needs TW module), Frame board, camera, telemetric switch, video recorder
Specifications are subject to change without notice.
We welcome your ideas! If you have developed any instrument you feel may have significant interest for applied neuroscience, physiology and/or pharmacology, we would like to hear and discuss about it.