How does a tick paralyze its host?

How does a tick paralyze its host? - briefly

Ticks inject saliva containing neurotoxic proteins that block acetylcholine release at neuromuscular junctions, preventing muscle contraction. This paralysis facilitates prolonged feeding by immobilizing the host.

How does a tick paralyze its host? - in detail

Ticks achieve host immobilization through a combination of salivary secretions, neurotoxic proteins, and physiological manipulation of the host’s nervous system. When a tick attaches, it inserts its hypostome into the skin and secretes a complex cocktail of bioactive molecules. These compounds serve three primary functions:

  • Anticoagulants and anti‑inflammatory agents prevent blood clotting and reduce host detection, creating a stable feeding site.
  • Immunomodulatory proteins suppress local immune responses, allowing prolonged attachment without eliciting a strong inflammatory reaction.
  • Neuroactive toxins interfere with synaptic transmission. Specific peptides bind to voltage‑gated sodium channels or acetylcholine receptors, reducing neuronal excitability and causing localized muscle weakness or paralysis.

The neurotoxic effect is dose‑dependent; even minute concentrations can depress nerve impulse propagation in the immediate area of the bite. This results in a loss of muscle tone around the feeding zone, limiting the host’s ability to groom or remove the parasite. In some species, the toxins spread systemically, leading to broader motor impairment that facilitates prolonged blood ingestion.

Additionally, ticks release enzymes that degrade extracellular matrix components, promoting deeper penetration of the feeding apparatus and enhancing the delivery of paralytic agents directly to nerve endings. The coordinated action of these salivary factors ensures the host remains still, reducing the risk of dislodgement and maximizing the tick’s blood intake over several days.