Ventromedial Thalamus-Projecting DCN Neurons Modulate Associative Sensorimotor Responses in Mice

Area of Science:

• Neuroscience
• Cerebellar Function
• Learning and Memory

Background:

• The deep cerebellar nuclei (DCN) are essential for motor control and learning.
• Specific neuronal subpopulations within the DCN and their precise roles in associative learning are not fully understood.

Purpose of the Study:

• To investigate the function of a specific subpopulation of DCN neurons projecting to the ventromedial (Vm) thalamus (DCN^Vm neurons).
• To determine the role of DCN^Vm neurons in associative sensorimotor learning, specifically trace eyeblink conditioning (tEBC).

Main Methods:

• Recording DCN^Vm neuron activity during tEBC in mice.
• Using optogenetics and chemogenetics to manipulate DCN^Vm neuron activity.
• Assessing the effects of DCN^Vm neuron manipulation on conditioned responses and motor coordination.
• Measuring neuronal activity in the cingulate cortex following DCN^Vm neuron activation.

Main Results:

• DCN^Vm neuron activity significantly correlated with conditioned eyeblink responses during tEBC.
• Optogenetic activation of DCN^Vm neurons amplified conditioned responses, while inhibition diminished them.
• Chemogenetic manipulation of DCN^Vm neurons did not affect non-associative motor coordination.
• Activation of DCN^Vm neurons rapidly increased activity in the cingulate cortex.

Conclusions:

• DCN^Vm neurons are critical components of the neural circuitry underlying associative sensorimotor learning.
• These neurons play a causal role in modulating the strength of conditioned responses.
• DCN^Vm neurons influence downstream brain areas like the cingulate cortex, contributing to the timing of learned responses.