Listening to spikes from a single neuron (tactile afferent) of an awake behaving human with a needle stuck in her wrist. See our paper for some data.
To remember the mechanosensitive structures at the ends of slowly adapting (class 1 or 2) and fast adapting (class 1 or 2) nerve afferents, think "life is Fast for MPs, Slow for MR.’s".
The fast-adapting MP stands for Meissner (class 1) and Pacini (class 2), and slow-adapting MR stands for Merkel (class 1)and Ruffini (class 2). Remember that the M in MP is Merkel because Merkel alphabetically comes before Meissner.