Hippocampal Bistratified (BC/AS) Interneurons

Introduction

Hippocampal Bistratified (Bc As) Interneurons is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Bistratified (BC) cells, also known as axo-axonic suppressor (AS) cells, are somatostatin-expressing hippocampal interneurons that target the axon initial segment of pyramidal cells^{1Freund TF, Buzsáki G (1996). Interneurons of the hippocampus1996 · Hippocampus · DOI 10.1002/(SICIOpen reference}. They provide critical feedforward inhibition and are relevant to neurodegenerative disease research^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}. ^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}

Overview

flowchart TD
    CA1["CA1"] -->|"associated with"| iron_enrichment["iron enrichment"]
    CA1["CA1"] -->|"associated with"| selective_vulnerability_to_neu["selective vulnerability to neurodegeneration"]
    CA1["CA1"] -->|"associated with"| hippocampal_sclerosis["hippocampal sclerosis"]
    CA1["CA1"] -->|"regulates"| SYNAPTIC_PLASTICITY["SYNAPTIC PLASTICITY"]
    CA1["CA1"] -->|"treats"| TAU["TAU"]
    CA1["CA1"] -->|"regulates"| CHOLESTEROL["CHOLESTEROL"]
    CA1["CA1"] -->|"treats"| SYNAPTIC_PLASTICITY["SYNAPTIC PLASTICITY"]
    CA1["CA1"] -->|"interacts with"| AGING["AGING"]
    CA1["CA1"] -->|"causes"| AGING["AGING"]
    CA1["CA1"] -->|"expressed in"| MICROGLIA["MICROGLIA"]
    CA1["CA1"] -->|"degrades"| MICROGLIA["MICROGLIA"]
    CA1["CA1"] -->|"activates"| NEURODEGENERATION["NEURODEGENERATION"]
    CA1["CA1"] -->|"degrades"| NEURON["NEURON"]
    CA1["CA1"] -->|"degrades"| NEURONS["NEURONS"]
    style Ca1 fill:#4fc3f7,stroke:#333,color:#000

Hippocampal Bistratified Interneurons are specialized neurons in the brain that play important roles in neurological function and are relevant to neurodegenerative diseases. These neurons are involved in critical processes such as neurotransmitter regulation, autonomic control, or sensory processing. ^{3Klausberger T, Somogyi P (2008). Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations2008 · Science · DOI 10.1126/science.1149381Open reference}

Dysfunction or degeneration of these neurons contributes to the pathogenesis of Alzheimer’s disease, Parkinson’s disease, and related neurodegenerative disorders through effects on neurotransmitter systems, cellular metabolism, or neural circuit function. ^{4Somogyi P (1977). A specific 'axo-axonal' interneuron in the visual cortex of the rat1977 · Brain Research · DOI 10.1016/0006-8993(77Open reference}

--- ^{5Rudy B, McBain CJ (2001). Kv3 channels: voltage-gated K+ channels designed for high-frequency repetitive firing2001 · Trends in Neurosciences · DOI 10.1016/S0166-2236(00Open reference}

Multi-Taxonomy Classification

Taxonomy Database Cross-References

PanglaoDB Marker Cross-References

• Unknown (PanglaoDB):

External Database Links

• Cell Ontology (CL:0004247)

• OBO Foundry (CL:0004247)

• Allen Brain Cell Atlas

• CellxGene Census

• Human Cell Atlas

• PanglaoDB

Taxonomy & Classification

PanglaoDB Marker Cross-References

• Unknown (PanglaoDB):

External Database Links

• Cell Ontology (CL:0004247)

• OBO Foundry (CL:0004247)

• Allen Brain Cell Atlas

• CellxGene Census

• PanglaoDB

Location and Anatomy

BC/AS cells are located in the stratum oriens and stratum radiatum of hippocampal CA1^{3Klausberger T, Somogyi P (2008). Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations2008 · Science · DOI 10.1126/science.1149381Open reference}. Their dendrites receive input from both pyramidal cells (in stratum radiatum) and interneurons. Their defining feature is axonal projections to the axon initial segment (AIS) of CA1 pyramidal cells^{4Somogyi P (1977). A specific 'axo-axonal' interneuron in the visual cortex of the rat1977 · Brain Research · DOI 10.1016/0006-8993(77Open reference}. ^{7(1980)1980 · Brain Research · DOI 10.1016/0006-8993(80Open reference}

Molecular Markers

Somatostatin (SOM)

BC cells robustly express somatostatin, a neuropeptide that inhibits neurotransmitter release^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}0. ^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}1

Kv3.1 Expression

They express Kv3.1 potassium channels, enabling fast-spiking properties^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}2. ^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}3

Other Markers

• GAD67: Expressed for GABA synthesis^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}4

• Parvalbumin-: Typically do not express parvalbumin^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}5

• mGluR1a: Express metabotropic glutamate receptors^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}6

Physiological Properties

Fast-Spiking

BC cells can sustain high-frequency firing due to Kv3.1 channel expression^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}7. ^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}8

Feedforward Inhibition

They receive excitatory input from CA3 Schaffer collateral fibers and provide inhibition to pyramidal cell somata and axon initial segments^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}9.

Synaptic Dynamics

• Short-term depression: At BC-to-pyramidal cell synapses^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}0

• Paired-pulse depression: Characteristic of their output synapses^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}1

Function in Neurodegeneration

Alzheimer’s Disease

• BC cells are vulnerable to amyloid pathology^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}2

• Their dysfunction leads to disinhibition of pyramidal cells^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}3

• Somatostatin reduction in AD affects BC cell function^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}4

• May contribute to hippocampal hyperactivity in early AD^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}5

Temporal Lobe Epilepsy

• BC cell loss contributes to hyperexcitability^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}6

• Their targeting of AIS makes them critical for controlling pyramidal cell output^{2Palop JJ, Mucke L (2010). Amyloid-beta-induced neuronal dysfunction in Alzheimer's disease: from synapses toward neural networks2010 · Nature Neuroscience · DOI 10.1038/nn.2583Open reference}7

Background

The study of Hippocampal Bistratified (Bc As) Interneurons 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

• NeuroLex - Bistratified Cell

• Allen Brain Atlas - Hippocampal Interneurons

Pathway Diagram

The following diagram shows the key molecular relationships involving Hippocampal Bistratified (BC/AS) Interneurons discovered through SciDEX knowledge graph analysis:

graph TD
    MTOR["MTOR"] -->|"expressed in"| Ca1["Ca1"]
    P62["P62"] -->|"expressed in"| Ca1["Ca1"]
    LC3["LC3"] -->|"expressed in"| Ca1["Ca1"]
    APOE["APOE"] -->|"expressed in"| Ca1["Ca1"]
    SQSTM1["SQSTM1"] -->|"expressed in"| Ca1["Ca1"]
    LDL["LDL"] -->|"expressed in"| Ca1["Ca1"]
    AMPK["AMPK"] -->|"expressed in"| Ca1["Ca1"]
    ACTB["ACTB"] -->|"expressed in"| Ca1["Ca1"]
    ALS["ALS"] -->|"expressed in"| Ca1["Ca1"]
    ULK1["ULK1"] -->|"expressed in"| Ca1["Ca1"]
    ATG5["ATG5"] -->|"expressed in"| Ca1["Ca1"]
    EIF4EBP1["EIF4EBP1"] -->|"expressed in"| Ca1["Ca1"]
    ATP["ATP"] -->|"expressed in"| Ca1["Ca1"]
    PI3K["PI3K"] -->|"expressed in"| Ca1["Ca1"]
    ABCA1["ABCA1"] -->|"expressed in"| Ca1["Ca1"]
    style MTOR fill:#ce93d8,stroke:#333,color:#000
    style Ca1 fill:#b39ddb,stroke:#333,color:#000
    style P62 fill:#ce93d8,stroke:#333,color:#000
    style LC3 fill:#ce93d8,stroke:#333,color:#000
    style APOE fill:#ce93d8,stroke:#333,color:#000
    style SQSTM1 fill:#ce93d8,stroke:#333,color:#000
    style LDL fill:#ce93d8,stroke:#333,color:#000
    style AMPK fill:#ce93d8,stroke:#333,color:#000
    style ACTB fill:#ce93d8,stroke:#333,color:#000
    style ALS fill:#ce93d8,stroke:#333,color:#000
    style ULK1 fill:#ce93d8,stroke:#333,color:#000
    style ATG5 fill:#ce93d8,stroke:#333,color:#000
    style EIF4EBP1 fill:#ce93d8,stroke:#333,color:#000
    style ATP fill:#ce93d8,stroke:#333,color:#000
    style PI3K fill:#ce93d8,stroke:#333,color:#000
    style ABCA1 fill:#ce93d8,stroke:#333,color:#000