Fig. 1. Schematic diagrams
of mechanosensory organs
in an insect and in a fish. (A)
depicts a mechanosensory
bristle in Drosophila, while (B)
depicts a lateral line
neuromast in Danio rerio. In
both cases the basic struc-
ture of the organ is one or
more mechanosensory cell(s)
surrounded by several sup-
port cells which generate the
external structure of the or-
gan, and accompanied by glial
cells. In the fly bristle, mecha-
noreception and signal trans-
duction are done by the same
cell, the sensory neuron. In
the fish organ (and in the in-
ner ear sensory epithelium,
which is evolutionarily related), mechanoreception takes place in specialized hair cells, while signal transduction occurs in the peripheral and central axons
of the sensory neuron. This difference may have allowed for an increased sensitivity in the vertebrate system, since the information from several hair
cells converges on a single sensory neuron.