02/04 Lecture 18 - Neurophysiology I

Voltage-gated ion channel

This is an ion channel that opens or closes depending on charges in the membrane

Equilibrium potential

This is a moment where an ions’ electrical and chemical gradients are in balance, and there is no net movement across the membrane

Chemical gated ion channel

This is an ion channel that opens or closes depending on the presence of a chemical

Mechanically gated ion channel

This is an ion channel that opens or closes in response to mechanical stimuli

Local current

This describes the movement of extracellular ions to replace the ones lost when they entered the cell

Hyper-polarisation

This describes a negative shift below -70mV in the membrane

Local potential

This is a change in membrane charge on a particular area of the cell

Relative refractory period

This is a period after the refractory period where the membrane can only respond to a larger than usual stimulus

Post-synaptic potential

This is a graded potential that develops in the post-synaptic membrane in response to a neurotransmitter

EPSP

This is a graded depolarisation that moves the membrane potential closer to the threshold

IPSP

This is a graded depolarisation that causes hyper-polarisation

Summation

This is the integration of the effects of graded potentials on an affected segment of membrane

Temporal summation

This occurs when a single synapse is repeatedly activated, without sufficient time for cooldown between activations

Spatial summation

This occurs when multiple synapses are activated at the same time

GABA

This is an inhibitory neurotransmitter