Motor Learning Rapidly Increases Cerebellar Synaptogenesis and Astrocytic Structural Plasticity
Mentor 1
Rodney Swain
Start Date
16-4-2021 12:00 AM
Description
The learning of motor skills has been found to coincide with synaptogenesis and astrocytic hypertrophy in the paramedian lobule of the cerebellum. Reports of these ultrastructural changes stem from analyses carried out after several weeks of training, at a time when skilled performance is relatively stable. The present experiment aimed to characterize cerebellar ultrastructure during the skill acquisition phase, at a time when motor skill learning is active and performance is still improving. Over the course of four days, adult male and female rats were trained on an acrobatic task that required the animals to traverse an elevated course consisting of obstacles such as narrow beams, springs, ladders, and high wires. Upon the completion of training, the animals were sacrificed and the cerebellum was removed, ultra-thin sectioned, and subsequently prepared for electron microscopy. Unbiased stereology techniques were then used to assess synaptic and astrocytic plasticity. The results of our experiment revealed that, relative to the motor control group, both males and females exhibited an increase in the density of parallel fiber-Purkinje cell synapses per Purkinje cell, a decrease in the parallel fiber-Purkinje cell synapse length, an increase in astrocytic volume, and an increase in the astrocyte coverage of Purkinje spines engaged in synapses with parallel fibers. In comparison to male rats, female rats made fewer errors and had shorter latencies during the initial day of training despite no differences in cerebellar ultrastructure. These morphological changes are probable contributors to motor skill learning.
Motor Learning Rapidly Increases Cerebellar Synaptogenesis and Astrocytic Structural Plasticity
The learning of motor skills has been found to coincide with synaptogenesis and astrocytic hypertrophy in the paramedian lobule of the cerebellum. Reports of these ultrastructural changes stem from analyses carried out after several weeks of training, at a time when skilled performance is relatively stable. The present experiment aimed to characterize cerebellar ultrastructure during the skill acquisition phase, at a time when motor skill learning is active and performance is still improving. Over the course of four days, adult male and female rats were trained on an acrobatic task that required the animals to traverse an elevated course consisting of obstacles such as narrow beams, springs, ladders, and high wires. Upon the completion of training, the animals were sacrificed and the cerebellum was removed, ultra-thin sectioned, and subsequently prepared for electron microscopy. Unbiased stereology techniques were then used to assess synaptic and astrocytic plasticity. The results of our experiment revealed that, relative to the motor control group, both males and females exhibited an increase in the density of parallel fiber-Purkinje cell synapses per Purkinje cell, a decrease in the parallel fiber-Purkinje cell synapse length, an increase in astrocytic volume, and an increase in the astrocyte coverage of Purkinje spines engaged in synapses with parallel fibers. In comparison to male rats, female rats made fewer errors and had shorter latencies during the initial day of training despite no differences in cerebellar ultrastructure. These morphological changes are probable contributors to motor skill learning.
