- Email: [email protected]
No abstract submitted
452
Abstracts
tightly reflected on the gross morphology of the pterothoracic ganglion.
16. No abstract submitted
rate a few seconds before the spontaneous initiation of walking. These units were not activated before the evoked initiation by mechanical stimulation. The results suggest that different parallel descending pathways are used for the spontaneous and evoked walking. We also found those descending units that were selectively activated during walking and those activated prior to the termination of walking. The parallel descending mechanisms underlying the control of walking was discussed.
doi:10.1016/j.cbpb.2008.09.017
doi:10.1016/j.cbpb.2008.09.019
17. Functional characterization of neuropiles in the crayfish brain: a study on freely behaving animals by optical telemetry
19. Adaptability of pheromone searching behavior of the silkmoth evaluated by an insect-controlled robot
Noriyuki Hama a, Yoshikazu Tsuchida b, Masakazu Takahata c, a Department Physiol., Sch. Medicine, Shimane Univ., Izumo 693-8501, Japan; b RIES, Hokkaido Univ., Sapporo 060-0812, Japan; c Div. Biol. Sci., Grad. Sch. Sci., Hokkaido Univ., Sapporo 060-0810, Japan
Noriyasu Ando, Shuhei Emoto, Hirokazu Takahashi, Ryohei Kanzaki, RCAST, The Univ. of Tokyo, Tokyo 153-8904, Japan
doi:10.1016/j.cbpb.2008.09.016
The crayfish brain contains many fine structures called neuropiles, which are related to specific functions respectively. The function of each neuropile, however, has remained largely unknown. Anatomical studies revealed that the olfactory information is conveyed to the central body (CB) and/or hemielipsoid body located in the protocerebrum. Somatosensory and visual sensory signals are also conveyed to these regions. Somatosensory information transmitted to the porotocerebrum is significantly modified depending on the animal's behavioral state. These facts suggest that the protocerebrum will act as the higher-order center for sensory inputs and/or motor outputs in crayfish. To test this possibility, we made extracelular recording from the brain of freely behaving crayfish using a glass micropipette filled with dye and a microdrive made of aluminum. This method allowed us to stably record the neuronal activity of the neuroplies from freely behaving crayfish for more than 1 h. We analyzed the response of neulopiles during the locomotor behavior and to sensory inputs. Only the CB responded to all sensory stimulation tested in this study and all neuropiles increased the neuronal activity during walking. These results suggested that the CB will function as a higher-order center for sensory information processing.
Insects perform adaptive behaviors and achieve a certain task in accordance with a ceaselessly changing environment. We have developed an insect-controlled robot to evaluate adaptability of insect behaviors. By manipulating a relationship between control signals (insect locomotion) and movements of the robot, we can induce unintentional displacements of the robot. And if the insect has adaptability, we can observe its compensatory behavior. In this study, we used male silkmoths (Bombyx mori) as drivers of the robot and analyzed trajectories of the robot during sex-pheromone searching behavior. The results indicated that the robot was successfully steered toward a pheromone source even though we manipulated the robot's motors to let it turn toward one side (biased side). During the orientation, the silkmoth performed compensatory behavior: it tended to execute turns opposed to the biased side. This compensatory behavior occurred within 1 s after starting the manipulation and required optic flow. We conclude that visual information is transmitted through a relatively fast sensory-motor pathway and modulates pheromone searching behavior for successful orientation. doi:10.1016/j.cbpb.2008.09.020
20. Cold adaptation of New Zealand weta and their lipids doi:10.1016/j.cbpb.2008.09.018
18. Parallel neural mechanisms underlying initiation, continuation and termination of spontaneous walking in crayfish Katsushi Kagaya, Masakazu Takahata, Department Biol. Sci., Fac. Sci., Hokkaido Univ., Sapporo 060-0810, Japan Animals can generate behaviors spontaneously without any external stimuli. The walking behavior is thus initiated, maintained and terminated spontaneously. Although command fibers for forward and backward walking have been long known, it has yet to be clarified how they are activated spontaneously to generate and control walking. The descending spike activity from the brain to the CPG in the thoracic ganglion could be considered to represent the motor commands for initiating the walking behavior. To understand the neural mechanism underlying the spontaneous initiation of walking in the crayfish Procambarus clarkii, we recorded extracellularly the activity of descending fibers from circumesophageal connective and analyzed their activity. We recorded simultaneously the leg muscle activity and quantified the walking pattern using a spherical treadmill system. We identified those descending units increasing their firing
Masazumi Iwasaki, Yukako Gotoh, Masanori Ochiai, Chihiro Katagiri, Biochem. Lab., Inst. Low Temp. Sci., Hokkaido Univ., Sapporo 0600819, Japan Wetas are indigenous orthopteran insects to New Zealand. They are known to adapt to low temperature and can overwinter during every stage of their life history. We are interested in the mechanism of their cold adaptation. We collected tree weta Hemideina femorata and alpine weta Hemideina maori in the South Island of New Zealand in Dec. 2006 and Dec. 2007. As a first step, we compared their cold tolerance with that of subtropical insects (cricket Gryllus bimaculatus and American cockroach Periplaneta americana) and silkworm (Bombyx mori). Crickets and cockroaches were torpified within 10 min at 0 °C, while wetas still responded to pinching stimulation to hindlegs over 1 h at 0 ° C. However, there was no difference among their freezing temperatures (ranging from −3 to −7 °C). Cold adaptation of organisms is often attributed to the unsaturation of lipids. We analyzed hydrocarbons that are synthesized in the oenocytes and transported to the outer surface of insects by lipophorin, a circulating lipid-transfer protein. Hydrocarbons are known to protect insects against dehydration. Wetas and silkworms have only saturated hydrocarbons, while crickets and cockroaches have both saturated and unsaturated hydrocarbons. In
Abstracts
tightly reflected on the gross morphology of the pterothoracic ganglion.
16. No abstract submitted
rate a few seconds before the spontaneous initiation of walking. These units were not activated before the evoked initiation by mechanical stimulation. The results suggest that different parallel descending pathways are used for the spontaneous and evoked walking. We also found those descending units that were selectively activated during walking and those activated prior to the termination of walking. The parallel descending mechanisms underlying the control of walking was discussed.
doi:10.1016/j.cbpb.2008.09.017
doi:10.1016/j.cbpb.2008.09.019
17. Functional characterization of neuropiles in the crayfish brain: a study on freely behaving animals by optical telemetry
19. Adaptability of pheromone searching behavior of the silkmoth evaluated by an insect-controlled robot
Noriyuki Hama a, Yoshikazu Tsuchida b, Masakazu Takahata c, a Department Physiol., Sch. Medicine, Shimane Univ., Izumo 693-8501, Japan; b RIES, Hokkaido Univ., Sapporo 060-0812, Japan; c Div. Biol. Sci., Grad. Sch. Sci., Hokkaido Univ., Sapporo 060-0810, Japan
Noriyasu Ando, Shuhei Emoto, Hirokazu Takahashi, Ryohei Kanzaki, RCAST, The Univ. of Tokyo, Tokyo 153-8904, Japan
doi:10.1016/j.cbpb.2008.09.016
The crayfish brain contains many fine structures called neuropiles, which are related to specific functions respectively. The function of each neuropile, however, has remained largely unknown. Anatomical studies revealed that the olfactory information is conveyed to the central body (CB) and/or hemielipsoid body located in the protocerebrum. Somatosensory and visual sensory signals are also conveyed to these regions. Somatosensory information transmitted to the porotocerebrum is significantly modified depending on the animal's behavioral state. These facts suggest that the protocerebrum will act as the higher-order center for sensory inputs and/or motor outputs in crayfish. To test this possibility, we made extracelular recording from the brain of freely behaving crayfish using a glass micropipette filled with dye and a microdrive made of aluminum. This method allowed us to stably record the neuronal activity of the neuroplies from freely behaving crayfish for more than 1 h. We analyzed the response of neulopiles during the locomotor behavior and to sensory inputs. Only the CB responded to all sensory stimulation tested in this study and all neuropiles increased the neuronal activity during walking. These results suggested that the CB will function as a higher-order center for sensory information processing.
Insects perform adaptive behaviors and achieve a certain task in accordance with a ceaselessly changing environment. We have developed an insect-controlled robot to evaluate adaptability of insect behaviors. By manipulating a relationship between control signals (insect locomotion) and movements of the robot, we can induce unintentional displacements of the robot. And if the insect has adaptability, we can observe its compensatory behavior. In this study, we used male silkmoths (Bombyx mori) as drivers of the robot and analyzed trajectories of the robot during sex-pheromone searching behavior. The results indicated that the robot was successfully steered toward a pheromone source even though we manipulated the robot's motors to let it turn toward one side (biased side). During the orientation, the silkmoth performed compensatory behavior: it tended to execute turns opposed to the biased side. This compensatory behavior occurred within 1 s after starting the manipulation and required optic flow. We conclude that visual information is transmitted through a relatively fast sensory-motor pathway and modulates pheromone searching behavior for successful orientation. doi:10.1016/j.cbpb.2008.09.020
20. Cold adaptation of New Zealand weta and their lipids doi:10.1016/j.cbpb.2008.09.018
18. Parallel neural mechanisms underlying initiation, continuation and termination of spontaneous walking in crayfish Katsushi Kagaya, Masakazu Takahata, Department Biol. Sci., Fac. Sci., Hokkaido Univ., Sapporo 060-0810, Japan Animals can generate behaviors spontaneously without any external stimuli. The walking behavior is thus initiated, maintained and terminated spontaneously. Although command fibers for forward and backward walking have been long known, it has yet to be clarified how they are activated spontaneously to generate and control walking. The descending spike activity from the brain to the CPG in the thoracic ganglion could be considered to represent the motor commands for initiating the walking behavior. To understand the neural mechanism underlying the spontaneous initiation of walking in the crayfish Procambarus clarkii, we recorded extracellularly the activity of descending fibers from circumesophageal connective and analyzed their activity. We recorded simultaneously the leg muscle activity and quantified the walking pattern using a spherical treadmill system. We identified those descending units increasing their firing
Masazumi Iwasaki, Yukako Gotoh, Masanori Ochiai, Chihiro Katagiri, Biochem. Lab., Inst. Low Temp. Sci., Hokkaido Univ., Sapporo 0600819, Japan Wetas are indigenous orthopteran insects to New Zealand. They are known to adapt to low temperature and can overwinter during every stage of their life history. We are interested in the mechanism of their cold adaptation. We collected tree weta Hemideina femorata and alpine weta Hemideina maori in the South Island of New Zealand in Dec. 2006 and Dec. 2007. As a first step, we compared their cold tolerance with that of subtropical insects (cricket Gryllus bimaculatus and American cockroach Periplaneta americana) and silkworm (Bombyx mori). Crickets and cockroaches were torpified within 10 min at 0 °C, while wetas still responded to pinching stimulation to hindlegs over 1 h at 0 ° C. However, there was no difference among their freezing temperatures (ranging from −3 to −7 °C). Cold adaptation of organisms is often attributed to the unsaturation of lipids. We analyzed hydrocarbons that are synthesized in the oenocytes and transported to the outer surface of insects by lipophorin, a circulating lipid-transfer protein. Hydrocarbons are known to protect insects against dehydration. Wetas and silkworms have only saturated hydrocarbons, while crickets and cockroaches have both saturated and unsaturated hydrocarbons. In