The subpedunculate lobe of the octopus brain: Evidence for dual function

Summary Two nerves arise from the subpedunculate lobe of the octopus brain. (1) The subpedunculate nerve, ending with neurosecretory terminals at the pharyngo-ophtalmic vein. It appears to be involved in growth and/or maturation. (2) The optic gland nerve, ending in the optic gland. Two types of synapses are found in the inactive optic gland (axo-axonal and axo-glandular); only one of them in the active gland (axo-glandular). The axo-axonal synapse is supposed to inhibit the axo-gladular synapse in immature glands.