# Determining the role of the Cuneate nucleus in the processing of proprioceptive information in the awake behaving animal

> **NIH NIH F31** · NORTHWESTERN UNIVERSITY · 2020 · $45,520

## Abstract

PROJECT SUMMARY
Patients who have lost the sense of proprioception demonstrate the necessity of understanding
this sense in explaining how the motor system is able to coordinate dexterous movements. An
important aspect in understanding any sensory system is the set of transformations that take
place in the pathway from simple receptors to rich and useful representations in cortex. In the
case of proprioception, knowledge of the early stages of processing are poorly understood. The
first proprioceptive synapse in the brain is in the Cuneate Nucleus (CN). Remarkably, encoding
of limb state by single CN neurons has never been examined in a non-anesthetized animal
before, despite 50 years of behavioral electrophysiology in other brain areas. I propose to
record from the CN of an awake behaving monkey to determine how proprioception is encoded
in this low-level area.
Two main receptor classes comprise the sense of proprioception; muscle spindles and Golgi
tendon organs encode muscle lengths and forces respectively. Previous experiments
investigating the CN have yielded contradictory results regarding the convergence of signals
from multiple muscles and receptor types, contradictions that may be explained by the effects of
anesthesia. Anesthesia suppresses cortical activity, which has been shown to send descending
signals to brainstem nuclei including CN. Additionally, studies investigating the effects of
anesthesia on transmission of proprioceptive signals have found evidence of attenuation of
muscle afferents while under surgical sedation. By studying the CN in the awake state, I will
remove these effects to better understand both the extent of spatial and modality convergence
of neurons in CN, as well as the effects of descending inputs on its transmission of
proprioceptive information.
I will conduct experiments which answer three aims. First, I will test the effect of anesthesia on
the representation of proprioception in single neurons of the CN of a monkey. With selective
receptor stimulation, I will characterize the responsiveness of neurons in the CN in both the
awake and anesthetized states. Second, using the selective receptor stimulation and encoding
models of CN neurons, I will test how single neurons in the CN represent information during
reaching behavior. Third, I will compare how the CN represents actively generated movements
to those generated by external perturbation, with an attempt to find efference copy in CN.
Through these aims, I will answer foundational questions about the role of CN in the afferent
proprioceptive pathway.

## Key facts

- **NIH application ID:** 9999687
- **Project number:** 5F31NS106833-03
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Christopher Versteeg
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $45,520
- **Award type:** 5
- **Project period:** 2018-09-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9999687

## Citation

> US National Institutes of Health, RePORTER application 9999687, Determining the role of the Cuneate nucleus in the processing of proprioceptive information in the awake behaving animal (5F31NS106833-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9999687. Licensed CC0.

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