IGF-1 Receptor Neurons

IGF-1 Receptor (IGF1R) Neurons

<table class="infobox infobox-cell">
<tr>
<th class="infobox-header" colspan="2">IGF-1 Receptor Neurons</th>
</tr>
<tr>
<td class="label">Taxonomy</td>
<td>ID</td>
</tr>
<tr>
<td class="label">Cell Ontology (CL)</td>
<td>[CL:0000197](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)</td>
</tr>
<tr>
<td class="label">Ligand</td>
<td>Affinity</td>
</tr>
<tr>
<td class="label">IGF-1</td>
<td>Highest</td>
</tr>
<tr>
<td class="label">IGF-2</td>
<td>High</td>
</tr>
<tr>
<td class="label">Insulin</td>
<td>Low</td>
</tr>
<tr>
<td class="label">Brain Region</td>
<td>Expression Level</td>
</tr>
<tr>
<td class="label">Cortex</td>
<td>High</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>High</td>
</tr>
<tr>
<td class="label">Brainstem</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Spinal Cord</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Hypothalamus</td>
<td>Moderate</td>
</tr>
</table>

Introduction

Igf 1 Receptor Neurons is an important cell type in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

...

IGF-1 Receptor (IGF1R) Neurons

<table class="infobox infobox-cell">
<tr>
<th class="infobox-header" colspan="2">IGF-1 Receptor Neurons</th>
</tr>
<tr>
<td class="label">Taxonomy</td>
<td>ID</td>
</tr>
<tr>
<td class="label">Cell Ontology (CL)</td>
<td>[CL:0000197](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)</td>
</tr>
<tr>
<td class="label">Ligand</td>
<td>Affinity</td>
</tr>
<tr>
<td class="label">IGF-1</td>
<td>Highest</td>
</tr>
<tr>
<td class="label">IGF-2</td>
<td>High</td>
</tr>
<tr>
<td class="label">Insulin</td>
<td>Low</td>
</tr>
<tr>
<td class="label">Brain Region</td>
<td>Expression Level</td>
</tr>
<tr>
<td class="label">Cortex</td>
<td>High</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>High</td>
</tr>
<tr>
<td class="label">Cerebellum</td>
<td>High</td>
</tr>
<tr>
<td class="label">Brainstem</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Spinal Cord</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Hypothalamus</td>
<td>Moderate</td>
</tr>
</table>

Introduction

Igf 1 Receptor Neurons is an important cell type in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

Neurons expressing the insulin-like growth factor 1 receptor (IGF1R) represent a critical population for neuronal survival, development, and function throughout the lifespan. IGF1R is a receptor tyrosine kinase that binds insulin-like growth factor 1 (IGF-1) with high affinity, as well as IGF-2 and insulin at lower affinity [@bondy2004]. These neurons are widely distributed in the brain and play essential roles in neuroprotection, synaptic plasticity, metabolism, and myelination. The IGF-1 system has emerged as a major therapeutic target for neurodegenerative diseases, particularly Alzheimer's disease and ALS.

<!-- multi-taxonomy-enrichment -->

Multi-Taxonomy Classification

Taxonomy Database Cross-References

External Database Links

• [Cell Ontology (CL:0000197)](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)
• [OBO Foundry (CL:0000197)](http://purl.obolibrary.org/obo/CL_0000197)
• [Allen Brain Cell Atlas](https://portal.brain-map.org/atlases-and-data/bkp/abc-atlas)
• [CellxGene Census](https://cellxgene.cziscience.com/)
• [Human Cell Atlas](https://www.humancellatlas.org/)

Molecular Biology of IGF1R

Gene and Protein Structure

The IGF1R gene is located on chromosome 15q26.3 in humans and encodes a 1,367-amino acid receptor precursor that is cleaved to form the mature heterotetrameric receptor [@igfr]. The receptor consists of:

• Alpha subunits (2x): Extracellular, bind IGF-1
• Beta subunits (2x): Transmembrane with intracellular tyrosine kinase domain
• Disulfide bonds: Connect subunits

Ligands

IGF1R binds multiple ligands with different affinities:

Signaling Pathways

IGF1R activates multiple intracellular cascades:

PI3K/Akt pathway: Major pro-survival signaling

MAPK/ERK pathway: Growth and differentiation

mTOR pathway: Protein synthesis, autophagy

PLCγ pathway: Calcium signaling

Distribution in the Nervous System

Brain Region Distribution

IGF1R-expressing neurons are found throughout the CNS:

Developmental Expression

• Prenatal: High expression during brain development
• Postnatal: Decreases but maintained throughout life
• Aging: Often reduced in aging brains
• Disease: Altered in neurodegeneration

Function in Normal Physiology

Neuronal Survival and Neuroprotection

IGF1R neurons are protected against various insults:

• Anti-apoptotic: Akt activation prevents cell death
• Anti-oxidant: Reduces oxidative stress
• Anti-excitotoxic: Protects against glutamate toxicity
• Energy metabolism: Improves glucose utilization

Synaptic Plasticity

In the cortex and hippocampus:

• LTPmechanisms/long-term-potentiation) promotion: Enhances long-term potentiation
• Dendritic complexity: Promotes dendritic growth
• Synapse formation: Facilitates synapse development
• Learning and memory: Essential for cognitive function [@torresaleman2010]

Myelination

IGF-1 promotes oligodendrocyte function:

• Oligodendrocyte survival: Via IGF1R signaling
• Myelin production: Supports myelination
• Remyelination: Promotes repair in disease

Metabolic Regulation

In the hypothalamus:

• Regulates food intake
• Controls energy expenditure
• Modulates glucose homeostasis

Role in Neurodegenerative Diseases

Alzheimer's Disease

IGF1R dysfunction is central to Alzheimer's disease pathogenesis:

IGF-1 Signaling Deficit:

• Reduced IGF-1 levels in AD brains
• Impaired IGF1R signaling
• Contributes to neuronal loss [@carro2002]

Amyloid Relationship:

• Aβ reduces IGF-1 signaling
• Creates vicious cycle of dysfunction
• Therapeutic implications

Therapeutic Strategies:

• IGF-1 delivery approaches
• IGF1R agonists
• Combined therapies

Amyotrophic Lateral Sclerosis (ALS)

IGF-1 is a major therapeutic target in ALS:

Motor Neuron Protection:

• IGF-1 protects motor neurons
• Multiple clinical trials conducted
• Controversial results [@lai1997]

Therapeutic Approaches:

• Intrathecal IGF-1 delivery
• Gene therapy (AAV-IGF1)
• Combination therapies

Parkinson's Disease

IGF-1 may be beneficial in Parkinson's disease:

• Protects dopaminergic neurons
• May improve function
• Clinical trials ongoing

Stroke and Brain Injury

IGF-1 is neuroprotective after injury:

• Reduces infarct size
• Promotes recovery
• Clinical trials for stroke

Therapeutic Targeting

IGF-1 and IGF1R Agonists

Clinical Use:

• Mecasermin: Recombinant human IGF-1 (approved for growth disorders)
• Mecasermin rinfabate: IGF-1/IGFBP-3 complex

Investigational:

• AAV-IGF-1 gene therapy
• Small molecule IGF1R agonists
• Peptide analogs

Challenges and Considerations

Side Effects:

• Hypoglycemia
• Peripheral edema
• Potential tumor promotion

Delivery:

• Blood-brain barrier penetration
• Intrathecal delivery options
• Gene therapy approaches

Genes and Proteins

• IGF1 Gene - Insulin-Like Growth Factor 1
• IGF1R Gene - IGF-1 Receptor
• IGFBP Proteins - IGF Binding Proteins
• Akt Protein

Cell Types

• Cortical Pyramidal Neurons
• Hippocampal CA1 Neurons
• Motor Neurons
• [Oligodendrocytes](/cell-types/oligodendrocytes)

Diseases

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis)
• Stroke

Mechanisms

• Neuroprotection
• Synaptic Plasticity
• Apoptosis Mechanisms
• Myelination

Background

The study of Igf 1 Receptor Neurons has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• NCBI Gene: [IGF1R](https://www.ncbi.nlm.nih.gov/gene/3480)
• UniProt: [IGF1R](https://www.uniprot.org/uniprot/P08069)
• Ensembl: [IGF1R](https://ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000138796)
• Allen Brain Atlas: [IGF1R expression](https://human.brain-map.org/microarray/search/show?search_term=IGF1R)
• PubMed: [IGF1R neurodegeneration research](https://pubmed.ncbi.nlm.nih.gov/?term=IGF1R+neurodegeneration)