Figure 1.

Schematic of the dendrite model (1000 µm length; 1 µm diameter) showing the extracellular space, cytosol and endoplasmic reticulum (ER). Thick black lines represent the plasma and ER membranes. The extracellular space provides a source and sink for multiple molecules. Ca²⁺, Na⁺, K⁺, and IP₃ are depicted as black circles. These molecules enter and exit the dendrite and its sub-compartments via the channels/receptors (gray pores) in directions indicated by arrows. SERCA pump moves cytosolic Ca²⁺ into the ER. Lightning symbols represent stimulus locations (AMPA-mediated depolarization; mGluR-mediated IP₃ augmentation). Dotted lines between molecules and receptors indicate the receptor is modulated by the molecule (e.g., Ca²⁺ activates K_Ca and IP₃R).