Synergism between insecticides permethrin and propoxur occurs through activation of presynaptic muscarinic negative feedback of acetylcholine release in the insect central nervous system

Fifth-instar nymphs of Rhodnius prolixus Stålwere exposed to the vapours of 11 volatile drugs: acetone, bromobenzene, bromoform, carbon tetrachloride, chloral hydrate, chloroform, dioxane, ethanol, ethyl ether, isopropanol and paraldehyde. Bromobenzene, bromoform, carbon tetrachloride, chloroform and ether induced reversible anaesthesia. For each of these five, the insects exhibited a different andspecific pattern of motor responses before becoming totally immobile; these responses are described. The responses to carbon tetrachloride are similar to the normal feeding responses of this insect. The other six drugs did not induce anaesthesia, but instead, a commonand stereotyped pattern of cleaning responses, suggesting irritation of the sensory organs. It is proposed that the agent-specific responses to the anaesthesiainducing drugs are due to their differential action upon specific portions of the insect central nervous system.

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Cell proliferation in the repairing adult insect central nervous system: incorporation of the thymidine analogue 5-bromo-2-deoxyuridine in vivo

Journal of Cell Science ◽

10.1242/jcs.95.4.599 ◽

1990 ◽

Vol 95 (4) ◽

pp. 599-604

Author(s):

P.J. Smith ◽

E.A. Howes ◽

J.E. Treherne

Keyword(s):

Central Nervous System ◽

Cell Proliferation ◽

Nervous System ◽

Blood Brain Barrier ◽

Glial Cells ◽

Past Research ◽

Thymidine Analogue ◽

Adult Insect ◽

Insect Central Nervous System

Uptake of the thymidine analogue 5-bromo-2-deoxyuridine into non-neuronal cells of the insect central nervous system has been examined following a controlled lesioning of the glial elements. The pattern of BUdR labelling along the penultimate abdominal connective was examined over a period of 17 days. Cell proliferation occurred in and immediately around the site of damage in both perineurial and subperineurial glial cells but at different times post-lesion for the two regions. Proliferation in the perineurial zone was maximal at 6–8 days post-lesion but continued for at least 17 days. Subperineurial proliferation was less dramatic and peaked between days 8–11 post-lesion. In both areas division appears to be confined to the reactive glial cells. These results are discussed in the context of past research on this system, particularly with regard to the restoration of the blood-brain barrier.

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Adipokinetic hormone stimulates neurones in the insect central nervous system.

Journal of Experimental Biology ◽

10.1242/jeb.198.6.1307 ◽

1995 ◽

Vol 198 (6) ◽

pp. 1307-1311

Author(s):

J J Milde ◽

R Ziegler ◽

M Wallstein

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Manduca Sexta ◽

Central Action ◽

Adipokinetic Hormone ◽

Metabolic Functions ◽

Simple Preparation ◽

Pressure Injection ◽

The Central Nervous System ◽

Insect Central Nervous System

A simple preparation designed to screen and compare the central action of putative neuroactive agents in the moth Manduca sexta is described. This approach combines microinjections into the central nervous system with myograms recorded from a pair of spontaneously active mesothoracic muscles. Pressure injection of either octopamine or Manduca adipokinetic hormone (M-AKH) into the mesothoracic neuropile increases the monitored motor activity. Under the conditions used, the excitatory effects of M-AKH exceed those of the potent neuromodulator octopamine. This suggests that M-AKH plays a role in the central nervous system in addition to its known metabolic functions and supports recent evidence that neuropeptides in insects can be multifunctional.

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