PSL201Y1 Chapter Notes -Catechol, Tetrahydrocannabinol, Enteric Nervous System
Document Summary
Electrical synapses: operate by allowing electrical signals to be transmitted from one neuron to another through gap junctions. Chemical synapses: operate through the release of neurotransmitters that activate signal transduction mechanisms. Exist between neurons, and neurons and glial cells. The plasma membrane of adjacent cells are linked together by gap junctions (electrical signal directly transferred to the adjacent cell by ions flowing). Allows rapid communication (usually bidirectional) between adjacent neurons that synchronizes the electrical activity in these cells. Communication can be excitatory or inhibitory at the same synapse, as either a depolarizing or a hyperpolarizing current can spread through the junctions. One neuron secretes a neurotransmitter into the extracellular fluid in response to an action potential arriving at its axon terminal. The neurotransmitter than binds to receptors on the plasma membrane of a second cell, triggering an electrical signal that may or may not initiate an action potential. Neuroeffector junction: a synapse between a neuron and an effector cell.
