Effect of Capsaicin and Other Thermo-TRP Agonists on Thermoregulatory Processes in the American Cockroach

Abstract

Capsaicin is known to activate heat receptor TRPV1 and induce changes in thermoregulatory processes of mammals. However, the mechanism by which capsaicin induces thermoregulatory responses in invertebrates is unknown. Insect thermoreceptors belong to the TRP receptors family, and are known to be activated not only by temperature, but also by other stimuli. In the following study, we evaluated the effects of different ligands that have been shown to activate (allyl isothiocyanate) or inhibit (camphor) heat receptors, as well as, activate (camphor) or inhibit (menthol and thymol) cold receptors in insects. Moreover, we decided to determine the effect of agonist (capsaicin) and antagonist (capsazepine) of mammalian heat receptor on the American cockroach’s thermoregulatory processes. We observed that capsaicin induced the decrease of the head temperature of immobilized cockroaches. Moreover, the examined ligands induced preference for colder environments, when insects were allowed to choose the ambient temperature. Camphor exposure resulted in a preference for warm environments, but the changes in body temperature were not observed. The results suggest that capsaicin acts on the heat receptor in cockroaches and that TRP receptors are involved in cockroaches’ thermosensation.

Bioactivity Profile of the Diterpene Isosteviol and its Derivatives

“…However, further studies are needed for its effects on the blood–brain barrier and during pregnancy, on whether it is safe to consume or not. For commercial and large-scale production of plant based important secondary metabolites, the expression of the genes that codes for the enzymes involved in their metabolic pathway into yeast or the tobacco plant offered an opportunity [ 28 , 29 ]. Gold et al expressed several genes that coded the different enzymes involved in the synthesis of steviosides in baker’s yeast, and the production of steviosides from glucose gave a good yield [ 30 ].…”

Role of transient receptor potential vanilloid‐1 in behavioral thermoregulation of the Mongolian gerbil Meriones unguiculatus

“…The time spent by the gerbils in different temperature zones of the plate within 120 min was recorded (Maliszewska et al . 2018).…”

Molecular bases of sensory processes in kissing bugs, vectors of Chagas disease

“…Most of these belong to a gene family named transient receptor potential receptors (TRPs), channels dedicated to hygro and chemosensation, as well as mechanoreception or phototransduction [33]. As with previous cases, the molecular bases of heat detection have been mostly shown for D. melanogaster, but a few examples have reported genes involved in heat detection in mosquitoes [34], cockroaches [35], and kissing bugs [36]. Recently, Ir93a, Ir25a, Ir40a and Ir21a have also been reported to be involved in thermo and hygrosensation in D. melanogaster [37].…”