# Subcellular investigation of molecular programs responsible for corticospinal neuron development and treatment-enhanced regeneration

> **NIH NIH F30** · HARVARD MEDICAL SCHOOL · 2024 · $53,974

## Abstract

Traumatic spinal cord injury (SCI) is an acquired disorder causing permanent functional deficits due to lack
of regenerative ability of the central nervous system (CNS). The inability of the CNS to re-generate is in stark
contrast with its ability to generate precise circuitry during development. Corticospinal neurons (CSN) are the
subtype of cortical projection neurons (PN) that normally connect the cerebral cortex to the spinal cord to control
voluntary motor output directly and indirectly. During development, CSN axons traverse vast distances to
establish segmentally-specific functional circuitry along the rostro-caudal spinal cord. Establishment of such
specific circuitry necessitates tightly regulated, dynamic developmental programs to progressively refine CSN
identity and their input and output connections. After injury, CSN do not normally re-establish functional
circuitry. Despite decades of research, and existence of multiple animal models of increased CSN regeneration,
the extent of functional recovery for people with SCI remains largely unchanged. This lack of clinical advance is
partly due to limitations of understanding of molecular mechanisms directly responsible for locally enacting axon
growth and guidance (or not), both during development and during attempted regeneration. In my proposed
work, I will investigate the distinct transcriptomes and proteomes of CSN growth cones (GCs) vs. somata during
development and after injury, toward selecting molecular candidates for functional manipulation.
 GCs are the cellular subcompartments at the ends of growing axons that directly enact neuronal subtype-
specific axon growth and guidance during development and after injury. Direct investigation of CSN GC
molecular machinery promises to elucidate local subcellular processes that underpin developmental and
regenerative CSN growth. My lab has recently developed experimental and analytic approaches to deeply
investigate subtype- and stage-specific GCs in vivo. These approaches have led to identification of neuronal
subtype-specific regulation of local RNA, protein, and translation in interhemispheric callosal and
corticothalamic projection neurons. My lab and I have purified thoracolumbar CSN (CSNTL) GCs and somata
from postnatal day 3 (P3), P5, and P7 mice, during axon elongation, grey matter innervation, and branching. I
will analyze the RNA sequencing data obtained, and will expand by addition of proteomics, to select candidates
for functional investigation (Aim 1). I will use a model of increased CSN regeneration after SCI (Pten deletion)
to investigate local RNA-protein of regenerating CSNTL (Aim 2). Why CNS regeneration does not occur after
injury is a critical unanswered, fundamental question with immense translational implications. My work aims to
elucidate developmental growth programs responsible for directing appropriate CSN axon elongation, segment-
specific branching and collateralization, and synapse targeting. Importantly, my wo...

## Key facts

- **NIH application ID:** 10892644
- **Project number:** 5F30HD113352-02
- **Recipient organization:** HARVARD MEDICAL SCHOOL
- **Principal Investigator:** Maria Alejandra Vicent Allende
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $53,974
- **Award type:** 5
- **Project period:** 2023-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10892644

## Citation

> US National Institutes of Health, RePORTER application 10892644, Subcellular investigation of molecular programs responsible for corticospinal neuron development and treatment-enhanced regeneration (5F30HD113352-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10892644. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*
