PIGMENT-DISPERSING HORMONE IMMUNOREACTIVE NEURONS IN THE BLOWFLY NERVOUS-SYSTEM

We could demonstrate pigment-dispersing hormone immunoreactive (PDHIR) neurons in the brain and ventral ganglia of the blowfly Phormia terra enovae. PDHIR neurons were found in the optic lobe. Their processes su pply the lamina, medulla and lobula complex bilaterally. Large PDHIR c ell bodies in the protocerebrum have processes in the proto- and trito cerebrum and axons to the aorta wall and foregut. Eight pairs of PDHIR neurons are found dorsally and three pairs ventrally in the fused abd ominal neuromeres; one pair is located ventrally in each of the thorac ic neuromeres. The ventral abdominal PDHIR neurons are efferents that innervate the hindgut. PDHIR neurons may play different functional rol es as neurohormones or neuromodulators in different parts of the nervo us system and its peripheral targets.