The release of neurosecretory material from A2 neurosecretory neurons (NSNs) was stimulated in Lymantria dispar fourth instar caterpillars exposed to a temperature of 35 °C for 1, 12, and 24 h, as well as those allowed recover after exposure (12 h at 35°C, then 12 h at 23 °C). | Turkish Journal of Biology Turk J Biol (2014) 38: 157-167 © TÜBİTAK doi: Research Article Temperature-induced stress response in Lymantria dispar neurosecretory neurons 1 1 1 2 Larisa ILIJIN , Milena VLAHOVIĆ , Vesna PERIĆ MATARUGA , Ivana KMETIČ , 1 1 1 Anja GAVRILOVIĆ , Dragana MATIĆ , Marija MRDAKOVIĆ 1 Department of Insect Physiology and Biochemistry, Institute for Biological Research Siniša Stanković, University of Belgrade, Belgrade, Serbia 2 Laboratory for Toxicology, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia Received: Accepted: Published Online: Printed: Abstract: The release of neurosecretory material from A2 neurosecretory neurons (NSNs) was stimulated in Lymantria dispar fourth instar caterpillars exposed to a temperature of 35 °C for 1, 12, and 24 h, as well as those allowed recover after exposure (12 h at 35 °C, then 12 h at 23 °C). The levels of 2 protein forms with the same molecular mass as bombyxin (3–4 and 4–5 kDa) increased with prolonged exposure to 35 °C. The second band was present only in the groups exposed to this stressor. There was intensified synthetic activity and a low level of secretion in L2’ NSNs after exposure to 35 °C. We previously found these NSNs to be immunopositive for prothoracicotropic neurohormone. After this stress, densitometric analysis revealed a decreased amount of the 11–12 kDa isoform (present in the control group). The new isoform (13–15 kDa), expressed after exposure of the insects to a high temperature, increased in amount with prolonged exposure and after recovery at 23 °C. Short-term exposure of caterpillars to high temperatures (35 °C) is a stressor and activates carbohydrate metabolism, while PTTH immunopositive NSNs are secretory-inactive during acute thermal stress regimes. Key words: High temperature, gypsy .
