Neurons:

A. may be myelinated by microglia.
B. secrete neurotransmitters from their nerve terminals in response to action potentials.
C. are the most abundance cell-type in the brain
D. often contain swellings at the nerve endings known as synaptic battons
E. conduct information following sub-threashold signal detection.

The correct answer is B. Neurons secrete neurotransmitters from their nerve terminals in response to action potentials.

To arrive at this answer, let's break down the options and eliminate the incorrect ones:

A. Neurons are myelinated by a different type of glial cell called oligodendrocytes, not microglia. So this option is incorrect.

C. While neurons are essential cells in the brain, they are not the most abundant. Other cell types like glial cells outnumber neurons. Therefore, this option is incorrect.

D. The swellings at the nerve endings of neurons are called synaptic boutons, not synaptic battons. Therefore, this option is incorrect.

E. Neurons conduct information following supra-threshold signal detection, which means they generate action potentials when a strong enough stimulus is detected. Sub-threshold signals do not result in information conduction. Hence, this option is incorrect.

This leaves us with option B, which states that neurons secrete neurotransmitters from their nerve terminals in response to action potentials. This is the correct answer.