A guide to the neuroanatomy of locust suboesophageal and thoracic ganglia

1982 ◽  
Vol 297 (1085) ◽  
pp. 91-123 ◽  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Fibre ◽  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Suboesophageal Ganglion ◽  
Thoracic Ganglia ◽  
Locusta Migratoria Migratorioides ◽  
Basic Framework ◽  
Metathoracic Ganglion ◽  
The Brain

The organization of the thoracic and suboesophageal ganglia in the locust is presented to provide a framework into which details of individual neurons can be inserted as information becomes available. Three species were examined, Chortoicetes terminifera (Walker), Schistocerca gregaria (Forskål) and Locusta migratoria migratorioides (Reiche and Fairmaire). The basic plan of the ganglia is similar in all three species. Series of selected sections in transverse, horizontal and sagittal planes are illustrated to show the arrangement of the main nerve fibre tracts and areas of neuropil, and these are described briefly. A guide is given to prominent features that assist in the interpretation of sections in each plane. In the simpler mesothoracic and prothoracic ganglia nine longitudinal tracts are present in each half of the neuromere, and six dorsal and four ventral transverse tracts (commissures) link the two halves. Four vertical or oblique tracts are conspicuous, the T-tract, ring tract, C-tract and I-tract. Major roots of each peripheral nerve useful as landmarks are numbered from anterior to posterior. Two regions of fine fibrous neuropil are prominent, the ventral association centre and an area associated with the ring tract, a little above it. In the metathoracic ganglion three abdominal neuromeres are fused posteriorly to the true metathoracic neuromere. All four neuromeres show modification of the basic framework chiefly in the arrangement of the ventral commissures and the degree of development of the ventral association centre. In the suboesophageal ganglion three neuromeres, mandibular, maxillary and labial, are fused together from anterior to posterior. They show increasing modification of the basic plan anteriorly. Additional anterior longitudinal tracts are present, which connect with the brain, the dorsal commissures are much reduced and compressed, particularly in the mandibular neuromere, and the ventral commissures of all three neuromeres differ considerably from those of the thoracic ganglia.

Pitch discrimination in locusts

1961 ◽  
Vol 155 (959) ◽  
pp. 218-231 ◽  
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Pitch Discrimination ◽  
High Pitch ◽  
Sound Stimulation ◽  
Sensory Axons ◽  
Metathoracic Ganglion ◽  
Tympanic Organ ◽  
The Brain ◽  
Stimulation Of

Sound stimulation of the tympanic organ of Locusta migratoria and Schistocerca gregaria initiates responses in the tympanic nerve and these in turn stimulate a few interneurones which ascend the ventral cord from the metathoracic ganglion to the brain. Some of the preparations show the following evidence of pitch discrimination. The response of the whole tympanic nerve to a pulsed note of low pitch cannot be made identical to the response to the same pulse at high pitch no matter how the relative inten­sities are adjusted. A continuous note, which presumably adapts some but not all of the primary receptors, modifies the relation between pre- and post-ganglionic responses in a way which depends on the pitch of the continuous note. The relative intensities of a pure tone of high pitch (10 to 15 kc/s) and one of low pitch (0.5 to 2.0 kc/s) can, in a preparation showing only ‘on' responses, be adjusted so that there is a post-ganglionic response to the former but not to the latter, although the latter causes a larger response in the tympanic nerve. Certain large interneurones, identifiable by their spike height, do not have the same curve of threshold to pulses of various pitch as does the summed response from the whole tympanic nerve. The post-ganglionic response is, therefore, towards a selected fraction of the sensory axons. In each of the above tests the effects are small and pitch discrimination cannot be of great significance for the life of the animal.

Operational Aspects of Locust Control

1966 ◽  
Vol 70 (672) ◽  
pp. 1077-1081
Author(s):  
D. Yeo
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Broad Band ◽  
Central Africa ◽  
Nomadacris Septemfasciata ◽  
Red Locust ◽  
Migratory Locust ◽  
Locusta Migratoria Migratorioides ◽  
The World ◽  
Locust Control

The crops of every continent of the world have been devastated from time to time by locusts or grasshoppers. To mention three major locust species, the Desert Locust (Schistocerca gregaria Forsk.) has caused havoc in a broad band of the world stretching from East Pakistan to Senegal and from the Mediterranean to Central Africa, the Red Locust (Nomadacris septemfasciata Serv.) has infested East, Central and Southern Africa, and the African Migratory Locust (Locusta migratoria migratorioides Rch. and Frm.) has plagued most of Africa south of the Sahara.What happens in one part of a plague area can significantly affect the situation in others and locust control is therefore an international problem, requiring international co-operation. Many of the threatened areas are countries where standards of living are not high and local agriculture is a mainstay of the economy; the regions are often inhospitable and lack modern roads, aerodromes and lines of communication.

scholarly journals Descending and Ascending Signals That Maintain Rhythmic Walking Pattern in Crickets

2021 ◽  
Vol 8 ◽  
Author(s):  
Keisuke Naniwa ◽  
Hitoshi Aonuma
Keyword(s):  
Nervous System ◽  
Gait Pattern ◽  
Gait Patterns ◽  
Control Center ◽  
Walking Gait ◽  
Thoracic Ganglia ◽  
Metathoracic Ganglion ◽  
Tripod Gait ◽  
The Brain ◽  
Leg Movements

The cricket is one of the model animals used to investigate the neuronal mechanisms underlying adaptive locomotion. An intact cricket walks mostly with a tripod gait, similar to other insects. The motor control center of the leg movements is located in the thoracic ganglia. In this study, we investigated the walking gait patterns of the crickets whose ventral nerve cords were surgically cut to gain an understanding of how the descending signals from the head ganglia and ascending signals from the abdominal nervous system into the thoracic ganglia mediate the initiation and coordination of the walking gait pattern. Crickets whose paired connectives between the brain and subesophageal ganglion (SEG) (circumesophageal connectives) were cut exhibited a tripod gait pattern. However, when one side of the circumesophageal connectives was cut, the crickets continued to turn in the opposite direction to the connective cut. Crickets whose paired connectives between the SEG and prothoracic ganglion were cut did not walk, whereas the crickets exhibited an ordinal tripod gait pattern when one side of the connectives was intact. Crickets whose paired connectives between the metathoracic ganglion and abdominal ganglia were cut initiated walking, although the gait was not a coordinated tripod pattern, whereas the crickets exhibited a tripod gait when one side of the connectives was intact. These results suggest that the brain plays an inhibitory role in initiating leg movements and that both the descending signals from the head ganglia and the ascending signals from the abdominal nervous system are important in initiating and coordinating insect walking gait patterns.

scholarly journals Neuromuscular systems in the fifth instar larva of silkworm Bombyx mori (Lepidoptera: Bombycidae): I-Cephalothoracic musculature and its innervation

2009 ◽  
Vol 1 (2) ◽  
pp. 201-209
Author(s):  
S. Sivaprasad ◽  
P. Muralimohan
Keyword(s):  
Bombyx Mori ◽  
Instar Larva ◽  
Compound Eyes ◽  
Suboesophageal Ganglion ◽  
Ventral Region ◽  
Thoracic Ganglia ◽  
Neuromuscular Systems ◽  
Frontal Ganglion ◽  
The Brain ◽  
Silkworm Bombyx Mori

The cephalo-thoracic musculature of the fifth instar larva of Bombyx mori comprises distinct groups of segmental muscle bands arranged in a stereotyped pattern. It includes dorsal, ventral, tergopleural, tergocoxal, lateral intersegmental, pleurosternal, sternocoxal, pleurocoxal and spiracular muscles. The cephalothoracic segments are innervated by the nerves of brain, suboesophageal ganglion (SG) and three thoracic ganglia (TG1, TG2, TG3).The brain gives nerves for compound eyes, antennae, labrum, frontal ganglion and the integument in the head. The SG, TG1,TG2,and TG3 give out a pair of lateral segmental nerves each, called the dorsal (DN) and ventral (VN) nerves. The DN of SG innervates muscles in the cephalic region, while its VN innervates muscles in the prothorax. The DN of thoracic ganglia innervates muscles in the dorsal, lateral and ventral regions of the hemi-segment while the VN innervates muscles in the ventral region. The innervation pattern indicates the presence of mixed nerves and multiple innervations that facilitate coordinated body movements and locomotion.

The inhibitory effect of seedling grasses on feeding and survival of Acridids (Orthoptera)

1974 ◽  
Vol 64 (3) ◽  
pp. 413-420 ◽  
Author(s):  
E. A. Bernays ◽  
R. F. Chapman ◽  
J. Horsey ◽  
E. M. Leather
Keyword(s):  
Schistocerca Gregaria ◽  
Locusta Migratoria ◽  
Time Lapse ◽  
Inhibitory Effect ◽  
Nomadacris Septemfasciata ◽  
Activity Levels ◽  
Locusta Migratoria Migratorioides ◽  
Mature Leaves ◽  
Time Spent Feeding ◽  
Survival Studies

AbstractThe amounts eaten by Locusta migratoria migratorioides (R. & F.) on seedling grasses was less than on mature grasses in four other Acridids, Nomadacris septemfasciata (Serv.), Chortoicetes terminifera (Wlk.), Melanoplus sanguinipes (F.) and Schistocerca gregaria (Forsk.). Palatability of the young grasses increases with age, becoming maximal 6–10 weeks from the time of germination. Similar preferences were shown by other Acridids. Time-lapse film studies on Locusta showed that not only is less time spent feeding on seedling grasses, but that locomotor activity levels are considerably higher. Survival studies on the same species showed higher mortality on the seedlings as compared with the mature leaves at all stages of nymphal development, while on seedlings no individuals survived to the adult stage. Lipid-soluble materials were removed from seedling leaves with chloroform or acetone and this rendered them more acceptable, while the extract applied to mature leaves resulted in reduced palatability.

scholarly journals Descending and ascending signals that maintain rhythmic walking pattern in the cricket

2020 ◽  
Author(s):  
Keisuke Naniwa ◽  
Hitoshi Aonuma
Keyword(s):  
Nervous System ◽  
Gait Pattern ◽  
Gait Patterns ◽  
Control Center ◽  
Walking Gait ◽  
Thoracic Ganglia ◽  
Metathoracic Ganglion ◽  
Tripod Gait ◽  
The Brain ◽  
Leg Movements

AbstractThe cricket is one of the model animals used to investigate the neuronal mechanisms underlying adaptive locomotion. An intact cricket walks with a tripod gait, similar to other insects. The motor control center of the leg movements is located in the thoracic ganglia. In this study, we investigated the walking gait patterns of crickets whose ventral nerve cords were surgically cut to gain an understanding of how the descending signals from the head ganglia and ascending signals from the abdominal nervous system into the thoracic ganglia mediate the initiation and coordination of the walking gait pattern. Crickets whose paired connectives between the brain and subesophageal ganglion (SEG) were cut exhibited a tripod gait pattern. However, when one side of the connectives between the brain and SEG was cut, the crickets continued to turn in the opposite direction to the connective cut. Crickets whose paired connectives between the SEG and prothoracic ganglion were cut did not walk, whereas the crickets exhibited an ordinal tripod gait pattern when one side of the connectives was intact. Crickets whose paired connectives between the metathoracic ganglion and abdominal ganglia were cut initiated walking, although the gait was not a coordinated tripod pattern, whereas the crickets exhibited a tripod gait when one side of the connectives was intact. These results suggest that the brain plays an inhibitory role in initiating leg movements, and that both the descending signals from the head ganglia and the ascending signals from the abdominal nervous system are both important in initiating and coordinating insect walking gait patterns.

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