Amphidial neurons ADL and ASH initiate sodium dodecyl sulphate avoidance responses in the infective larva of the dog hookworm Anclyostoma caninum

• Published in: International journal for parasitology 2004-11, Vol.34 (12), p.1333-1336
• Main Authors: Ketschek, A.R., Joseph, R., Boston, R., Ashton, F.T., Schad, G.A.
• Format: Article
• Language: English
• Subjects: Ablation; Ancylostoma - physiology; Ancylostoma caninum; animal behavior; Animal protozoal diseases; Animals; Antiparasitic Agents; Biological and medical sciences; Caenorhabditis elegans; chemical avoidance reactions; Chemosensation; Dogs; Fundamental and applied biological sciences. Psychology; Haemonchus contortus; hookworms; Infectious diseases; Larva; Laser microbeam; Lasers; Life cycle. Host-agent relationship. Pathogenesis; Medical sciences; Movement; Nematoda; Nematode; nematode larvae; neuronal ablation; Neurons - physiology; Parasite; Parasitic diseases; Protozoa; Protozoal diseases; repellents; sensation; sensilla; sensory neurons; Sodium Dodecyl Sulfate; sulfates
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2004.08.008

Ablations of specific amphidial neuron pairs with a laser microbeam were conducted to understand better the neurological basis of the behaviours of larval parasitic nematodes. To date, the functions of the amphidial neurons of Caenorhabditis elegans and their counterparts in parasitic nematodes have been found to be remarkably conserved allowing the possibility to predict the relationships between neurons and their functions. Therefore, we anticipated that ablation of neuron pairs ASH and ASK would abrogate avoidance of sodium dodecyl sulphate (SDS) by infective larvae (L3i) of Anclyostoma caninum. Instead, we have found that laser microbeam ablation of these neuron pairs did not eliminate SDS avoidance in A. caninum, but that neuron pairs ASH and ADL are the amphidial neurons responsible for SDS repulsion. When a droplet of the repellent is placed in the direct path of a normal A. caninum L3i, a strong backward avoidance response is triggered. However, when the ASH and ADL neurons are ablated, the nematodes demonstrate the opposite reaction, increasing their movement in a forward direction.