Dendrites make up 90% of the neurons surface area. Hillock is area of low electrical resistance dense in voltage-gated na+ channels. Currents move not by the flow of electrons but by the shuffling of electrons. Chemical synapse is the most common type, high electrical resistance, uses neurotransmitters. Epsp 15 ms long, increase in conductance to na+ (primarily) and k+, is 1 mv in size. Ipsp is also transient and has an increase in conductance to cl- and k+. Play a role in brain development, excitatory neurotransmission, synaptic plasticity and memory formation. Found in the hippocampus (structure concerned with memory) Main excitatory neurotransmitter is glutamate, glycine acts as inhibitory at the spinal cord and brainstem. Myasthenia gravis increase in width of synapse, decrease in number of receptors. Long-term potentiation has been found in the hippocampus and neocortex, maintenance is probably mediated by both pre- and post-synaptically. Occurs mainly at excitatory synapses which have nmda receptors. temporal summation is more effective.