Lolitrem B is one of many toxins produced by a fungus called Epichloë festucae var.

The condition is especially common in New Zealand and Australia, and plant breeders there have been trying to develop strains of fungus that produce toxins only harmful to pests, and not to mammals.

[1] The fungus produces lolitrem B, one of several mycotoxins that kill pests but which also can be neurotoxins for mammals.

[1] When animals eat ryegrass stems infected with E. f. lolii they get a condition called perennial ryegrass staggers; in cases of mild poisoning the animals get tremors, and in severe poisoning they stagger and collapse.

[5][6] Lolitrems distinguish themselves among tremorgenic neurotoxins because they induce a long lasting effect on motor function and heart rate.

[6][8] Lolitrem B likely acts synergistically with ergotamine to increase smooth muscle contraction.

[1] Plant breeders have been working with mycologists in Australia and New Zealand to develop strains of fungus that produce mycotoxins that are toxic to pests but not to mammals.

[1] Until those become commercially established the best prevention is avoiding grazing livestock on ryegrass when the stems are emerging and while the plant is flowering (concentrations are highest in the mature inflorescence and in the base of the plant), and avoiding overgrazing; once the exposure to lolitrem B ends the symptoms gradually decrease.

[1] These channels open temporarily to allow neurons to "reset" after they fire; lolitrem B blocks them, preventing the neuron from firing again after it depolarizes, which at low doses leads to tremors and at high doses to paralysis and death.

[18] The BK channels modulate neurotransmitter release, the form of the action potential and repetitive firing.

The difference between them is the position and number of aryl and hydroxyl substituents plus the absence or presence of an I ring.

[23] Intermediate metabolites such as terpendoles and paspaline can become lolitrems by addition of two rings (A and B) at the C20-C21 position to the indole moiety of the molecule.

Young et al 2009 provides predictions of variation in indole-diterpene synthesis ability between Epichloë spp.