Primitive nervous systems: Electrical activity in ventral nerve cords of the flatworm,Notoplana acticola

1. Electrical activity accompanying motor activity can be recorded from the excised pharynx of Enchiridium punctatum. Multiple stimuli elicit behaviour which consists of an initial aperture closure followed by extension and then peristalsis. If the stimulus parameters are increased the preparation bends from side to side instead of proceeding through the behavioural sequence. Bending appears to inhibit other movements differentially. 2. The conduction involved with peristalsis is polarized and proceeds in a proximal direction. 3. With stimulus intensities greater than those needed to produce the behavioural response an initial muscle potential (IMP) is evoked. The IMP is frequency sensitive. Maximum facilitation occurs within 100 ms and drops to 50% of maximum within 250 ms. 4. Conduction velocities of the IMP range from 0–05 m s-1 to 1-9 m s-1. Conduction velocities appear to increase with facilitation.

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ROMANES' RESEARCHES ON PRIMITIVE NERVOUS SYSTEMS

Science ◽

10.1126/science.ns-5.118.388 ◽

1885 ◽

Vol ns-5 (118) ◽

pp. 388-389

Keyword(s):

Nervous Systems ◽

Primitive Nervous Systems

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ACETYLCHOLINE IN PERIPLANETA AMERICANA L.: III. ACETYLCHOLINE IN ROACHES TREATED WITH TETRAETHYL PYROPHOSPHATE AND 2,2-BIS(p-CHLOROPHENYL)-1,1,1-TRICHLOROETHANE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y59-027 ◽

1959 ◽

Vol 37 (1) ◽

pp. 259-272 ◽

Cited By ~ 4

Author(s):

E. H. Colhoun

Keyword(s):

Electrical Activity ◽

Topical Treatment ◽

Mode Of Action ◽

Nerve Cord ◽

Nervous Tissue ◽

Periplaneta Americana ◽

Nervous Activity ◽

Thoracic Nerve ◽

Physiological Properties ◽

Nerve Cords

The levels of acetylcholine (ACh) in the thoracic nerve cords of cockroaches were increased by the topical application of 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and of tetraethyl pyrophosphate (TEPP), but only TEPP inhibited cholinesterase (ChE). Improvements in the correlation of symptoms, nervous activity, and ACh levels with ChE were obtained when nerve cords were homogenized in saline containing ACh, which prevented further inhibition of ChE by TEPP found to be present in blood and nervous tissue. There was a similarity in the distribution of ACh in thoracic nerve cords of roaches after topical treatment with TEPP and DDT but the physiological properties of the blood revealed differences in the mode of action of the two insecticides. The effects of blood from the poisoned insects on the electrical activity of the isolated nerve cord of roaches are discussed in relation to the penetration of the nerve cord by known neurohumors.

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Cytochemical observations on the nervous system of adult Corrigia vitta

Journal of Helminthology ◽

10.1017/s0022149x00013122 ◽

1993 ◽

Vol 67 (3) ◽

pp. 189-199 ◽

Cited By ~ 7

Author(s):

C. A. Magee ◽

M. Cahir ◽

D. W. Halton ◽

C. F. Johnston ◽

C. Shaw

Keyword(s):

Nervous System ◽

Egg Production ◽

Peptide Yy ◽

Confocal Scanning Laser Microscopy ◽

Nervous Systems ◽

Confocal Scanning ◽

Immunocytochemical Techniques ◽

Peripheral Nervous Systems ◽

Confocal Scanning Laser ◽

Nerve Cords

AbstractAdult Corrigia vitta (Trematoda: Dicrocoelidea) inhabit the pancreatic duct of the fieldmouse, Apodemus sylvaticus, where, in numbers, they may occlude the duct lumen and prevent the flow of pancreatic secretions. Enzyme histochemical and immunocytochemical techniques, in conjunction with confocal scanning laser microscopy, have been used to examine the localization and distribution of cholinergic. serotoninergic (5-HT, serotonin) and peptidergic components of the nervous system of the adult worm. All three classes of neuronal mediator showed a common pattern of staining, occurring throughout the central and peripheral nervous systems. Of the four peptide immunoreactivities (IR) demonstrated (pancreatic polypeptide (PP), peptide YY (PYY), substance P (SP), FMRFamide), PP-IR was the most predominant, occurring not only within the central ganglia and longitudinal nerve cords, but also in subtegumental plexuses and in fibres associated with the egg-forming apparatus. PYY and FMRFamide IRs were evident throughout the central and peripheral nervous systems; FMRFamide immunostaining, in particular, highlighted innervation of the ootype and immunoreactive cell bodies around the Mehlis' gland. Both SP- and 5-HT-IRs were restricted to the cerebral ganglia, ventral nerve cords and associated cell bodies. The distribution pattems of these peptides and 5-HT within the nervous system of C. vitta suggest they are likely to function as neuronal mediators. PP, PYY and FMRFamide may also serve in regulating egg production.

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