Biology Reference
In-Depth Information
FIGURE 9.2
Dissection of giant axons. A diagram illustrating the position of the squid giant axons after
removal of the internal organs and pen. The squid mantle is roughly conical after the head and
tentacles are removed. At that point, the mantle is cut along the dorsal midline to create flat
sheet of muscle. The viscera can then be removed along with clear stiff pen located in the
center of the ventral side of the mantle, between the two largest giant axons. All axons exist in
pairs on the right and left side of the midline. The largest diameter axons extend the paralleling
of the midline and are the longest axons. The other smaller axons are not used because they
are not typically large enough to extrude. The two largest giant axons are dissected free from
the surrounding muscle and threads are tied at the distal (green) and proximal ends (red, near
the cell bodies in the stellate ganglion)
thread (black for distal and white for proximal ends). The ganglion is freed from
the mantle and the distal end of the nerve beyond the ligation. The nerve should
be handled by the threads to avoid damage. Axons from
Loligo
with mantles
>
0.3 m typically run 400-500
m
m in diameter and will produce
2.5
m
l/cm of
giant axon.
