Question

Neuron A makes a synapse on a dendrite on a motorneuron and neurotransmission at this synapse produces a 5 mV depolarization immediately adjacent to the synapse.

B. Are EPSPs larger after they travel through a soma or a dendrite (assuming equal distance travelled)? Why?

Answer 1

EPSPs or Excitatory Post Synaptic Potential increase the likelihood of postsynaptic action potential. On reaching a neuron, an action potential will first go through the dendrites and then reach the cell body. Neurons do not usually sum inputs linearly and there are multiple active mechanisms in the dendrite that can amplify or attenuate the inputs on their way to the soma. Studies have shown that there is a physiological asymmetry in dendritic signalling for normal functions of the cell. All this points to the assumption that ESPS are larger after they travel through the dendrite.