Psychology 2220A/B Lecture Notes - Lecture 6: Axon Hillock, Distance Decay, Phagocytosis

• School: Western University
• Department: Psychology
• Course: Psychology 2220A/B
• Professor: Jody Culham

Document Summary

Decay function is steeper for small diameter axons. This is why ap propagate faster in large-diameter axons (squids) Unmyelinated = propagation combination of passive & active rely on active (slow) Passive c takes voltage current short way & then active conductance takes it further. Myelinated = propagation jumps from node to node. Passive conductance through myelinated (no channels ,", no active conductance) Faster & don"t need sodium potassium pump because there are no channels open at myelin. Passive pushes ap above threshold for active conductance to regenerate it. Passive c takes voltage current further than active. Temporal: psps that arrive from the same neutron close in time are combined. Come in rapidly & send post-synaptic membrane above threshold. Spatial: psps that arrive from different neurons (close in time) are combined. If components closer together than more likely to trigger ap. Their impact can be stronger if neurons closer in space. If epsps ipsps > threshold then ap starts at hillock.