====== Astrocytic Function ======

**Astrocytic function** encompasses the diverse physiological roles played by astrocytes in maintaining CNS homeostasis, supporting neuronal networks, and coordinating brain metabolism and blood flow.

===== 🔬 Core Functions =====

  * **Neurotransmitter regulation**:
    - Uptake of glutamate via EAAT1/2 to prevent excitotoxicity.
    - GABA and adenosine recycling.
  * **Ion buffering**:
    - K⁺ spatial buffering during neuronal activity.
  * **Neurovascular coupling (NVC)**:
    - Astrocytic endfeet detect synaptic activity and signal to nearby blood vessels.
  * **Energy metabolism**:
    - Lactate production and shuttling to neurons (astrocyte-neuron lactate shuttle).
  * **Synaptic modulation**:
    - Tripartite synapse: astrocytes modulate synaptic strength and plasticity.
  * **Water homeostasis**:
    - Regulation through AQP4 in astrocytic endfeet.
  * **Blood-brain barrier (BBB) support**:
    - Structural and paracrine support for endothelial tight junctions.

===== 🧪 Developmental and Regional Specificity =====

  * Astrocyte function varies by **brain region**, **age**, and **reactive state**.
  * In early postnatal stages (e.g., P8), astrocytes show heightened plasticity and involvement in NVC development.
  * Expression of key molecules (e.g., SorCS2, AQP4) can be developmentally regulated.

===== ⚠️ Dysfunction Consequences =====

  * **Excitotoxicity** due to failed glutamate clearance.
  * **Impaired NVC** and brain perfusion.
  * **Edema** from disrupted AQP4 localization or function.
  * **Neuroinflammation** and glial scarring (reactive astrogliosis).
  * Contribution to neurodegenerative diseases and epileptogenesis.

===== 🔗 Related Pages =====

  * [[astrocyte_dysfunction]]
  * [[neurovascular_coupling]]
  * [[glutamatergic_neurotransmission]]
  * [[AQP4]]
  * [[SorCS2]]
  * [[tripartite_synapse]]
  * [[reactive_astrogliosis]]