Neuropathological Studies of Chickens Following Exposure to Chlorpyrifos


  • Guru Angad Dev Veterinary and Animal Sciences University, Departments of Veterinary Pathology, College of Veterinary Science, Ludhiana, India
  • Guru Angad Dev Veterinary and Animal Sciences University, Pharmacology and Toxicology, College of Veterinary Science, Ludhiana, India


The objective of this study was to determine the putative neuropathological effects in young chickens after administration of a single dose of 55 mg/kg bw chlorpyrifos. The gross lesions of the nervous system comprised of congestions in the brain. Microscopic examination of brain showed mild congestion of cerebral blood vessels and mild perivascular cuffing of lymphomononuclear cells in the cerebral cortex and necrosis of the neurons. The interesting findings were the presence of cytoplasmic vacuolations of cerebral neurons and swelling of the endothelial cell of the cerebral capillaries. Cerebellum showed congestion and hemorrhages in the granular layer and necrosis of Purkinje cell. Sciatic nerve exhibited mild edema, swelling and degeneration of axons, and swelling of Schwann cells. There was a significant inhibition of plasma cholinesterase enzyme activity in chickens administered with chlorpyrifos compared to chickens of control group. The study revealed that administration of chlorpyrifos produces neuropathological lesions in chickens shortly after exposure.


Chickens, chlorpyrifos, neuropathological effects

Subject Discipline


Full Text:


Eto M. Organophosphours pesticides: Organic and biological chemistry. Boca Raton: CRC Press; 1979. p. 248.

Ritchardson RJ, Moore TB, Kayyali US, Randall JC. Chlorpyrifos: Assessment of potential for delayed neurotoxicity by repeated dosing in adult hens with monitoring of brain acetylcholinesterase, brain and lymphocyte neurotoxic esterase, and plasma butyrylcholinesterase activities. Fundam Appl Toxicol 1993;21:89-96.

Veronesi B. A rodent model of organophosphorus-induced delayed neuropathy: Distribution of central (spinal cord) and peripheral nerve damage. Neuropathol Appl Neurobiol 1984;10:357-68.

Tanaka D, Bursian SJ, Lehning EJ, Aulerich RJ. Delayed neurotoxic effect of bis (1-methylethyl) phosphorofluoridate (DFP) in the European ferret: A possible mammalian model for organophosphorus-induced delayed neurotoxicity. Neurotoxicology 1991;12:209-24.

Moretto A, Capodicasa E, Lotti M. Clinical expression of organophosphate-induced delayed polyneuropathy in rats. Toxicol Lett 1992;63:97-102.

Pope CN, Chakraborti TK, Chapman ML, Farrar JD. Longterm neurochemical and behavioral effects induced by acute chlorpyrifos treatment. Pharmacol Biochem Behav 1992;42:251-6.

Rowe LD, Warner SD, Johnston RV. Acute delayed neurotoxicologic evaluation of chlorpyrifos in white Leghorn hens. Dow Chemical Company, USA report A1A-715, dated 22 May 1978. Available from: chlorpyrifos_tox.pdf [last cited on 1978].

Capodicasa E, Scapellato ML, Moretto A, Caroldi S, Lotti M. Chlorpyrifos-induced delayed polyneuropathy. Arch Toxicol 1991;65:150-5.

Luna LG. Manual of histological staining methods of Armed Forces Institute of Pathology. New York: Mc Graw Hill book Co; 1968.

Khozhai LI, Otellin VA, Neokesariiskii AA. Postnatal morphological changes in neurons and glial cells in neocortex of mice developing at the background of serotonin deficit. J Evolut Biochem Physiol 2007;43:350-5.

Essawy AE, Abdelmeguied NE, Radwan MA, Hamed SS, Hegazy AE. Neuropathological effect of carbamate molluscicides on the land snail, Eobania vermiculata. Cell Biol Toxicol 2009;25: 275-90.

Paljarvi L, Rehncrona S, Sderfeldt B, Olsson Y, Kalimo H. Brain lactic acidosis and ischemic cell damage: Quantitative ultrastructural changes in capillaries of rat cerebral cortex. Acta Neuropathol 1983;60:232-40.

Balint Z, Krizbai IA, Wilhelm I, Farkas AE, Parducz A, Szegletes Z, et al. Changes induced by hyperosmotic mannitol in cerebral endothelial cells: An atomic force microscopic study. Eur Biophys J 2007;36:113-20.

Jortner BS, Ehrich M. Neuropathological effects of phenyl saligenin phosphate in chickens. Neurotoxicology 1987;8: 97-108.

Roberts NL, Phillips CN, Gopinath C, Begg S, Anderson A, Dawe IS. Acute delayed neurotoxicity study with chlorpyrifos in the domestic hen. Huntingdon Research Centre Ltd, UK. Study completed 14 May 1987. HRC report no. MBS 16/87764. MCW reference no. R-4661. Available from: http://www.apvma. [last cited on 1987].


  • There are currently no refbacks.