scholarly journals Short Communication: Do Presynaptic Muscarinic Receptors Regulate Acetylcholine Release in the Central Nervous System of the Cockroach Periplaneta Americana?

1989 ◽  
Vol 142 (1) ◽  
pp. 447-451 ◽  
Author(s):  
BERNARD HUE ◽  
BRUNO LAPIED ◽  
CLAIRE O. MALECOT
1993 ◽  
Vol 175 (1) ◽  
pp. 305-311
Author(s):  
H. Le Corronc ◽  
B. Hue

Biochemical studies of the central nervous system (CNS) of locusts (Breer and Knipper, 1984; Knipper and Breer, 1988) have provided evidence for a muscarinic negative feedback mechanism in which muscarinic antagonists and agonists, respectively, enhance and decrease the acetylcholine (ACh) output. More recently, this inhibitory action of presynaptic muscarinic acetylcholine receptors (mAChrs) has been demonstrated in cockroach (Hue et al. 1989; Le Corronc et al. 1991) and in tobacco hornworm (Trimmer and Weeks, 1989) using electrophysiological methods. However, in insects, most experiments have not been performed under physiological conditions but in the presence of acetylcholinesterase inhibitors or exogenous agonists. The aim of this study was to determine whether the release of ACh at a central synapse in the cockroach, Periplaneta americana, could be modulated by endogenous ACh acting on presynaptic muscarinic receptors.


1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE

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.


1962 ◽  
Vol 39 (3) ◽  
pp. 319-324
Author(s):  
K. G. DAVEY

1. Addition of a homogenate of corpora cardiaca to the fluid bathing an isolated hind gut of Periplaneta produces an increase in tonus, amplitude, frequency and co-ordination of contractions. 2. The corpus cardiacum acts by stimulating cells in the upper colon to release an indolalkylamine. 3. This amine acts on the mucles through a peripheral nervous system which can function in isolation from the central nervous system.


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