PSYB65H3 Lecture Notes - Congenital Disorder, Epileptic Spasms, Myoclonus
Document Summary
Summed up in soma; if enough excitation, signal sent down axon. Ion channels (pores) in neuron membrane, whenever neuron stimulated, channels open up, allow na+ into cell; when na+ comes inside, inside becomes more positive; if enough input, enough na+ will come into cell to make membrane potential reach threshold. When threshold reached, all channels in immediate vicinity open up, na+ pours in, makes inside of cell extremely +ve = sharp spike = very brief and then comes back down action. *whenever inside of cell becomes positive (not just because of na+), it opens up pores in vicinity. Positive-ness spreads very quickly so that more na+ can come in. When ap reaches end of axon, come to contact point btn two cells = synapse (usu. axon of one cell contacting dendrite of next cell) Inside axon terminal = synaptic vesicles contain neurotransmitters/transmitter substances.