In IB Biology HL C2.2.14, excitatory and inhibitory inputs combine at a postsynaptic neuron. Their effects change membrane potential and determine whether threshold is reached.
Describe how decision-making in the central nervous system (CNS) can result from the interaction between the activities of excitatory and inhibitory presynaptic neurons at synapses.
a. several presynaptic neurons synapse with one postsynaptic neuron;
b. excitatory presynaptic neurons depolarize postsynaptic neurons whereas inhibitory presynaptic neurons hyperpolarize postsynaptic neurons;
c. some excitatory presynaptic neurons may not be able to depolarize/cause an action potential in the postsynaptic neuron alone;
d. usually many needed to cause postsynaptic transmission;
e. some inhibitory presynaptic neurons may block/cancel depolarization (in postsynaptic neuron);
f. postsynaptic action potential/response/decision making determined by summation of all signals;