# Defining the roles and regulation of neuronal autophagy

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2020 · $367,878

## Abstract

PROJECT SUMMARY
Autophagy is a lysosomal degradation pathway that is critical to maintain neuronal homeostasis and survival.
Autophagy sequesters damaged and aged cellular components from the intracellular environment and targets
them to lysosomes for destruction. Defective autophagy is linked to neurodevelopmental abnormalities and
neurodegeneration in mammals. Further, activating autophagy can rescue models of neurodegeneration and
age-related cognitive decline in mice. Little is known, however, about the regulation and functions of autophagy
that provide neuroprotection. Much of the work to date elucidating the molecular basis of autophagy has been
performed in model systems that lack the morphological complexity of neurons. Further, our research has
revealed that several canonical paradigms, including starvation and mTOR-inhibition, that trigger autophagy in
non-neuronal cells do not robustly induce autophagy in neurons. Thus, it is critical to study autophagy directly
in neurons to provide insight that may improve therapies to mitigate diseases of neuronal dysfunction. Thus,
the objective for this proposal is to define the roles and regulation of neuronal autophagy that facilitate
neuronal function and survival. We established that autophagy in neurons is a highly compartmentalized
process. Axonal autophagy is a unidirectional pathway that allows cargo delivery from distant regions of the
axon to the soma for degradation. In contrast to the long-range pathway for autophagy in axons, dendritic
autophagy is defined by bidirectional movement of autophagic vacuoles (AVs) that may execute more localized
functions. Our preliminary data have identified three aspects of neuronal biology (synaptic connectivity,
neurotrophic support, and interactions with astrocytes) that regulate autophagy in specific neuronal
compartments. We find that synaptic activity controls AV dynamics selectively in dendrites and not in the axon.
We find that the neurotrophin BDNF induces retrograde autophagic flux along axons. Lastly, we find that co-
culturing neurons with astrocytes decreases autophagosome density in axons. The mechanistic basis for these
pathways and their functions, however, are unknown. Based on our preliminary data, we hypothesize that
synaptic activity, neurotrophins, and astrocytes differentially regulate autophagy in neurons, and, that
autophagy plays compartment-specific roles in neuronal function and survival. To test this hypothesis,
we will pursue three aims: (1) Define how synaptic activity regulates neuronal autophagy and how autophagy
affects synapse function; (2) Determine how neurotrophins regulate neuronal autophagy and how autophagy
impacts neurotrophin signaling; and (3) Elucidate how neuronal autophagy is regulated by astrocytes. We will
use quantitative approaches in cell biology, biochemistry, and electrophysiology to gain a mechanistic
understanding for each pathway. These studies will comprehensively map the pathways and functions fo...

## Key facts

- **NIH application ID:** 9973460
- **Project number:** 1R01NS110716-01A1
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Sandra L. Maday
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $367,878
- **Award type:** 1
- **Project period:** 2020-05-15 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9973460

## Citation

> US National Institutes of Health, RePORTER application 9973460, Defining the roles and regulation of neuronal autophagy (1R01NS110716-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9973460. Licensed CC0.

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