PSL201Y1 Chapter Notes - Chapter 8: Axon Terminal, Signal Transduction, Electrochemical Gradient
Document Summary
Electrical synapses allow electrical signals to be transmitted from one neuron to another through gap junctions. Exist between neurons, or between a neuron and glial cell. All for rapid communications between neurons, and synchs their electrical activity. Can be excitatory (depolarizing) or inhibitory (hyperpolarizing) Found in retina, areas of the cortex and brainstem, Chemical synapses release neurotransmitters that active signal transduction mechanisms in the target cell. Presynaptic neuron secretes neurotransmitter into extracellular fluid in response to action potential (ap) arriving at its axon terminal. Nt binds to receptors on plasma membrane of postsynaptic neuron which may/may not trigger action potential. Exist between neurons, or between a neuron and effector organ (ex. muscle/gland cells) Synaptic cleft: space between pre- and post-synaptic neuron. Axodendritic synapse: from presynaptic neuron"s axon terminal to postsynaptic neuron"s dendrite. Axoaxonic synapse: from presynaptic neuron"s axon terminal to postsynaptic neuron"s axon terminal: modulates communication at axodendritic and axosomatic synapses.
