What is a PRESYNAPTIC LOCUS/LOCI?

Neurons send messages to other neurons via chemical messengers called neurotransmitters. There is a small gap between the two neurons called the SYNAPSE where one neuron shoots out its neurotransmitters and they eventually bind to the corresponding receptor on the other neuron. The neuron sending out the message is the PRESYNAPTIC neuron [it is before the beginning of the synaptic gap hence this name]. Therefore, the presynaptic locus is simply this neuronal area.

you're suitable approximately them being initiated on the axon hillock. The positioned up-synaptic nerve doesnt get carry of enter from only one presynaptic nerve; diverse nerves converge onto it. The inputs from each and every nerve return and forth to the axon hillock as graded potentials. those indicators combine to be sure the internet ability which will or won't hearth an AP on the axon hillock. interior the state of affairs you describe that is that the positioned up-synaptic nerve is recieving a stronger inhibitory enter than excitatory enter and so the internet ability is subthreshold and an AP does not consequence.