Eyelid conditioning to a target amplitude: adding how much to whether and when

Area of Science:

• Neuroscience
• Computational Neuroscience
• Learning and Memory

Background:

• Pavlovian eyelid conditioning is a valuable tool for studying cerebellar computation and learning.
• Current procedures have limitations in controlling response amplitude, hindering investigations into cerebellar learning mechanisms.
• The error signal in traditional eyelid conditioning does not decrease with learning, limiting its utility.

Purpose of the Study:

• To develop and characterize a novel training procedure for eyelid conditioning that allows experimental control over conditioned response amplitude.
• To investigate cerebellar mechanisms underlying the learning and encoding of adaptive movement amplitude.
• To provide a foundation for systematic studies on cerebellar involvement in motor learning.

Main Methods:

• Developed a new training procedure where the unconditioned stimulus (US) delivery is contingent on conditioned response amplitude.
• Trained rabbits using either a tone or mossy fiber stimulation as the conditioned stimulus.
• Inactivated the interpositus nucleus using muscimol infusions to assess cerebellar involvement.

Main Results:

• Rabbits learned conditioned responses that approached target amplitudes (2-5 mm) with the new procedure.
• Inactivation of the interpositus nucleus abolished conditioned responses, confirming cerebellar involvement.
• Cerebellar involvement was not exclusive to traditional Pavlovian procedures.

Conclusions:

• The developed training procedure offers better experimental control over conditioned response amplitude in eyelid conditioning.
• Response amplitude is learned and encoded within the cerebellum during eyelid conditioning.
• This method facilitates controlled investigations into the cerebellar mechanisms responsible for learning and encoding adaptive movement amplitudes.