The Effects of Methylglyoxal on Central Synaptic Transmission in the Isolated Nerve Cord of the Cockroach (Periplaneta Americana L)

1985 ◽  
pp. 337-341 ◽  
Author(s):  
P. L. Chambers ◽  
M. G. Davies ◽  
M. J. Rowan
Keyword(s):  
Synaptic Transmission ◽  
Nerve Cord ◽  
Periplaneta Americana

The Penetration of Acetylcholine into the Central Nervous Tissues of an Insect (Periplaneta Americana L.)

1965 ◽  
Vol 43 (1) ◽  
pp. 13-21
Author(s):  
J. E. TREHERNE ◽  
D. S. SMITH
Keyword(s):  
Synaptic Transmission ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Extracellular Fluid ◽  
Physiological Role ◽  
Intracellular Uptake ◽  
Rapid Accumulation ◽  
Stage Process ◽  
Hydrolysis Of

1. 14C-labelled acetylcholine was found to penetrate rapidly into the tissues of the intact abdominal nerve cord. Uptake in the presence of 10-4 M eserine occurred as a two-stage process, the initial rapid influx being identified as the penetration into the extracellular system of the nerve cord. 2. There was a more rapid accumulation of radioactivity in normal preparations as compared with those treated with 10-4 M eserine, presumably as a result of intracellular uptake of the products of hydrolysis of the acetylcholine. 3. The level of radioactivity in the rapidly exchanging fraction was consistent with the hypothesis that the acetylcholine ions were distributed in the extracellular fluid according to a Donnan equilibrium with the haemolymph in eserinized preparations. 4. These results are discussed in relation to the possible physiological role of acetylcholine in synaptic transmission in this insect.

Sodium and Potassium Fluxes in the Abdominal Nerve Cord of the Cockroach, Periplaneta Americana L

1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Unit Area ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Nerve Sheath ◽  
The Central Nervous System ◽  
Sodium And Potassium

1. The influx of sodium and potassium ions into the central nervous system of Periplaneta americana has been studied by measuring the increase in radioactivity within the abdominal nerve cord following the injection of 24NA and 42K. into the haemolymph. 2. The calculated influx of sodium ions was approximately 320 mM./l. of nerve cord water/hr. and of potassium ions was 312 mM./l. of nerve cord water/hr. These values are very approximately equivalent to an influx per unit area of nerve cord surface of 13.9 x 10-2 M cm. -2 sec.-1 for sodium and 13.5 x 10-12 M cm. -2 sec.-1 for potassium ions. 3. The relatively rapid influxes of these ions are discussed in relation to the postulated function of the nerve sheath as a diffusion barrier. It is suggested that a dynamic steady state rather than a static impermeability must exist across the sheath surrounding the central nervous system in this insect.

Organization of the Giant Axons of the Cockroach Periplaneta Americana

1969 ◽  
Vol 50 (3) ◽  
pp. 615-627
Author(s):  
M. E. SPIRA ◽  
I. PARNAS ◽  
F. BERGMANN
Keyword(s):  
Nerve Cord ◽  
Periplaneta Americana ◽  
Thoracic Ganglion ◽  
American Cockroach ◽  
Abdominal Ganglion ◽  
Common Pathway ◽  
Average Delay ◽  
Giant Axons ◽  
Stimulation Of

1. Stimulation of the connectives between the suboesophageal and prothoracic ganglia of the American cockroach induced ipsilateral descending spikes in the abdominal giant axons with an average delay of 0·6 msec, per thoracic ganglion. 2. Nicotine at 5 µg./ml. had no effect on conduction in the abdomen but blocked ascending responses sequentially at the 6th abdominal ganglion then at the levels of T1; T2, and T3. 3. Simultaneous descending and ascending impulses resulted in mutual extinction along the nerve cord with the point of collision depending on the interval between stimuli. 4. It is suggested that a common pathway subserves ascending and descending giant impulses and models for bi-directional conduction are discussed.

The pharmacology of an insect ganglion: actions of carbamylcholine and acetylcholine

1976 ◽  
Vol 64 (1) ◽  
pp. 13-23
Author(s):  
D. B. Sattelle ◽  
A. S. McClay ◽  
R. J. Dowson ◽  
J. J. Callec
Keyword(s):  
Synaptic Transmission ◽  
Dose Response ◽  
Response Curve ◽  
Periplaneta Americana ◽  
Electrophysiological Recording ◽  
Cholinergic Agonists ◽  
Giant Fibre ◽  
Response Data ◽  
Gap Technique ◽  
Monosynaptic Epsp

1. Methods for presenting dose-response data for the ganglionic actions of cholinergic agonists (e.g. carbamylcholine) are compared, using the mannitol-gap technique for electrophysiological recording of synaptic events at the cercal nerve, giant fibre synapse of the sixth abdominal ganglion of the cockroach Periplaneta americana. 2. At concentrations around 10(−5)M, carbamylcholine has no effect on ganglionic polarization but potentiates the monosynaptic EPSP. At 10(−4)M and higher concentrations, ganglionic depolarization is accompanied by a reduction of EPSP. 3. Pretreatment with eserine (10(−6) M) considerably shifts the dose-response curve for acetylcholine so that synaptic transmission is consistently sensitive to 10(−6) M acetylcholine.

Electrical stimulation—Effects on the protein in the ventral nerve cord of cockroach,Periplaneta americana

1985 ◽  
Vol 94 (4) ◽  
pp. 407-411 ◽  
Author(s):  
S L Maheswari ◽  
K Balasundaram ◽  
V R Selvarajan
Keyword(s):  
Electrical Stimulation ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Periplaneta Americana

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

1959 ◽  
Vol 37 (1) ◽  
pp. 259-272 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document