Necator americanus (The Human Hookworms)
The Human Hookworm is a free‐living soil nematode that eats bacteria and is therefore constantly exposed to potential pathogens. Like other invertebrates, it lacks an adaptive immune system. It also does not appear to have specialized immune cells. The human Hookworm possesses three different types of defences against microbial attacks. It has been demonstrated that worms are able to distinguish between different bacteria. Whereas most bacteria, force the nematode away and cause an avoidance behaviour.
Worms can also “remember” odors and can even learn to avoid bacteria that are recognized as poison. This discrimination relies in part on pairs of asymmetric chemosensory neurons. Their correct development requires a signalling cassette that also has an intracellular acting cascade. It also plays a behavioral role because it has been proven to be involved in neuroendocrine regulation.
Worms can also “remember” odors and can even learn to avoid bacteria that are recognized as poison. This discrimination relies in part on pairs of asymmetric chemosensory neurons. Their correct development requires a signalling cassette that also has an intracellular acting cascade. It also plays a behavioral role because it has been proven to be involved in neuroendocrine regulation.