PS263 Study Guide - Midterm Guide: Ligand-Gated Ion Channel, Exocytosis, Unit
Document Summary
The key function of neurons is to organize info received from many other neurons. Delays in communications occur when one neuron communicates with another at the synapse. Temporal summation: repeated stimuli within brief time have cumulative effect. Spatial summation: combined synaptic inputs from separate locations combine their effect. Spontaneous firing rate: most neurons have periodic production of action potentials even without synaptic input. Ipsp: inhibitory postsynaptic potential, temporary hyperpolarization of membrane, synaptic input selectively opens gates for potassium ions carrying positive charge to leave cell or for negative chloride ions to enter cell. Neurons synthesize chemicals/neurotransmitters in axon terminals and neuropeptides in cell body. Calcium releases neurotransmitters from terminals which diffiuse across synaptic cleft and attach to receptors to alter activity of postsynaptic neuron. Neurons that release serotonin, dopamine, norepinephrine contain mao enzyme that breaks transmitters into inactive chemicals. Depolarization opens voltage dependent calcium gates in presynaptic terminal and causes exocytosis (bursts of release of neurotransmitter from presynaptic neuron)
