Inside the heart
of Ligia exotica
Ligia heart was opened and stretched out after
incision of the ventral wall. Inside the heart, there's the cardiac
ganglion, a cluster of the heart pacemaker neurons. There are six neurons
found in the main trunk of the cardiac ganglion.
These nerve processes were stained by intracellular
injection of Neurobiotin Tracer (Vector Lab.). into the soma of
the cardiac ganglion neuron. Scale bar in left pic, 500 micron.
The cardiac ganglion neurons project nerve fiberes
onto all over the heart wall and make neuromuscular junctions with
the cardiac muscles. Their neurotransmitter is glutamic acid.
The soma of the cardiac ganglion neuron is
seen in the middle pic as a swelling of the nerve process beside the scale
bar. Fine short processes are also seen near the soma. There are the varicosities
along a fine branch in the right pic.
Back to the heart figures...