Insects nervous system

Octopamine is one of the most abundant biogenic amines found in the insect nervous system. Its ubiquitous presence in nervous systems coupled to its broad range of actions has led to a rapid accumulation of knowledge about this amine, which is considered to be the insect equivalent of epinephrine and norepinephrine. Octopamine has both central and peripheral actions, where it serves as a... 

Nathanson, J.A. "Cyclic AMP A Possible Role in Insect Nervous System Function", Ph.D. Thesis, Yale University, New Haven,... 

This possibility was confirmed by injecting 5 yl N-acetyl OA (26 nmoles) into the cockroach haemocoel and monitoring levels of the derivative at various times following injection. If it is assumed that the haemolymph volume is 175 yl (24), the concentration of N-acetyl OA immediately following injection is 148.57 yM and, as indicated by the results in Table III, this value is reduced by 44% within 30 min. N-Acetyl OA is inactive against neuromuscular preparations from decapod crustaceans (25) and studies from this laboratory demonstrate that the derivative has no effect on adenylate cyclase activity in the insect nervous system (26). The relatively low rate of removal of N-acetyl OA compared with that of OA (see Table II) suppports the contention that the N-acetylation pathway produces a neurally non-active product. 

We decided to study changes in the chemistry of the insect nervous system following behavioural changes. We used the preparation devised by Horridge (1962) where he set up two cockroaches so that one got a shock every time its leg touched... 

Hodgson, E. S. and Wright, A. M. (1963) Action of epinephrine and related compounds upon the insect nervous system. Gen. comp. Endocr., 3,519-525. 

The further classification of conventional insecticides, acting chiefly on the insect nervous system, is a chemical one compounds of natural origin, arsenic compounds, chlorinated hydrocarbons, organophosphorus compounds, carbamates, and other compounds. 

Harrelson, A.L. (1992) Molecular mechanisms of axon guidance in the developing insect nervous system. J. Exp. Zool. 261 310-321. 

Soon after development of OP insecticides such as parathion, extensive electrophysiological studies were commenced for the purpose of elucidating the physiological rnechani.sm of action of OPs/CMs on the insect nervous system. The.se studies were conducted almost at the same time as nonmedical CM anti-ChEs were examined. Many of these studies conducted in the late 1940s through the early 1960s involved vertebrate neuromuscular junctions and insect. synaptic transmission. The effects of OPs/CMs on insect synapse,s are described later. 

N ssel, D. R. (1996) Advances in the immunocytochemical localization of neuro-active substances in the insect nervous system. J. Neurosci. Methods, in press. Cuello, A. C., ed. Immunohistochemistry. IBRO Handbook Series Methods in Neurosciences, vol. 3, Wiley, Chichester, UK. 

Klemm,N. andAxelsson, S. (1973) Detection of dopamine, noradrenaline and 5-hydroxytryptamme in the cerebral ganglion of the desert locust, Schistocerca gregana Forsk (Insecta Orthoptera). Brain Res 57,289-298 Evans, P. (1978) Octopamine distribution in the insect nervous system. J Neurochem 30, 1009—1013. 

Baines, R. A., Zhou, P, Midgley, J. M., Bacon, J. P., and Watson, D. G. (1996) p-Tyramine is a precursor for both p-octopamine and dopamine in the insect nervous system determination by GC/MS of deuterium incorporation. J. Neurochem, submitted for publication. 

Evans, P. D. (1980) Biogenic amines in the insect nervous system. Adv, Insect Physiol 15,317—473... 

Fipronil and its predominant sulfone metabolite are unique among insecticides in that they have three known high-affinity target sites - the three ligand-gated chloride channels that mediate most inhibitory transmission in the insect nervous system GABA receptors and the two subtypes of GluCls that have been de-... 

In Europe, bifenazate received a unanimous positive vote by the EU legislative meeting for Annex I inclusion under Council Directive 91/414/EEC in 2005 [4]. Preliminary results from studies on the mode of action of bifenazate in insects indicate that, at high concentrations, bifenazate acts on the postsynaptic GABA receptor in the insect nervous system. This mode of action has not yet been con-... 

The insect nervous system provides the preferred taget pool for all major insecticide classes (Fig. 8.28). Whereas the pyrethroids deregulate signal transduction by keeping the presynaptic sodium channel open for a prolonged period, the 8.28 The target of many carbamates inhibit reversibly and the phosphate esters irreversibly acetylcho-... 

Insecticide Compounds, Acting on the Acetylcholine Receptor of the Insect Nervous System... 

Nassel DR (1996) Advances in the immunocy-tochemical localization of neiuoactive substances in the insect nervous system. J Neurosci Methods 69 3-23... 

In insects poisoned by organic phosphorus compounds, assays for acetylcholinesterase show that this enzyme becomes increasingly inhibited dvuring the first hour and the levels of free acetylcholine rise sharply (Small-man and Fisher, 1958). This rise causes a great increase in spontaneous nerve activity (neuronal hyperexcitation), both autonomic and somatic. This state brings about liberation of tissue toxins, ion imbalance, with eventual paralysis, dehydration, and death this sequence is reminiscent of that caused by the chlorinated insecticides (see Section 7.6c for this comparison and for general information on biochemistry of the insect nervous system). 

The pyrethrins possess the most desirable combination of high biological activity coupled with low mammalian toxicity. The synthetic pyrethroids have been improved over the pyrethrins to achieve a thousand fold increase in activity with even lower mammalian toxicity (Naumann, 1990a Henrick, 1995). The pyrethrins and pyrethroids are considered to act on almost all parts of the nervous system of insects in their primary mode of action. They are speculated to act stereospecifically to block sodium channels in excitable nerve membranes in several parts of the insect nervous system to rapidly produce loss of coordinated movement, periods of convulsive activity and ultimate paralysis (Ruigt, 1985). The pyrethrins which produce repetitive discharges in the peripheral and central nervous system are classified as Type I pyrethroids. Type II pyrethroids (most modem synthetics) block the action potentials without inducing repetitive after discharges (Soderlund and Bloomquist, 1989 Henrick, 1995). 

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