effect of ethanol consumption on fear response in human and conventional animal models (rodents) is controversial. the present study aimed to investigate the effect of ethanol administration on fearfulness in poultry as an alternative animal model.being a reliable measure in avian species, tonic immobility was used to evaluate the fear response in 60 roosters orally administered with ethanol. d...

Tonic immobility, characterized by profound motor inhibition, is elicited under inescapable threat in many species. To fully support the existence of tonic immobility in humans, our aim was to elicit this reaction in a laboratory setting and measure it objectively. To mimic exposure to life-threatening events in the lab, trauma-exposed participants with PTSD (n=18) and without PTSD (n=15) liste...

Tonic immobility is a basic defense strategy which has not been studied in depth in humans. Data suggest that it may be a relatively frequent phenomenon in victims of rape and sexual abuse, but its occurrence has not been systematically explored in other types of trauma. We carried out a retrospective study in a sample of 100 university students to establish whether tonic immobility varies depe...

Death-feigning, also called tonic immobility, is found in a number of animal species across vertebrate and invertebrate taxa. To date, five hypotheses have been proposed for the adaptive significance of tonic immobility. These are that tonic immobility is effective for prey because (i) avoiding dead prey is safer for predators, (ii) immobility plays a role in physical defence, (iii) immobility ...

OBJECTIVE Tonic immobility is a defensive reaction occurring under extreme life threats. Patients with posttraumatic stress disorder (PTSD) reporting peritraumatic tonic immobility show the most severe symptoms and a poorer response to treatment. This study investigated the predictive value of tonic immobility for posttraumatic stress symptoms in a non-clinical sample. METHODS One hundred and...

Tonic immobility reaction and heterophil:lymphocyte ratio were studied in hens laying pink eggs from three brown egg Spanish breeds (Barred Red Vasca, Red Vasca, Red Villafranquina). There was no significant difference among breeds in terms of tonic immobility duration or heterophil:lymphocyte ratio. Tonic immobility duration was significantly shorter in the pink (220 + or - 23 s) than in the n...

Common pheasant (Phasianus colchicus) hens kept in different housing systems during laying period were exposed to a tonic immobility test. At the end of the laying period, the shortest duration of the tonic immobility, and thus the lowest fear level, was found in birds kept in enriched cages, i.e. cages equipped with 2 perches and a hiding place. The duration of the tonic immobility in hens kep...