Manganese (Mn) is an industrial neurotoxicant in humans and animal models limited to rodent species. The present study analyses the potential neurotoxicity of acute Mn administration in young chicks. The acute (24 h) LD50 values of Mn following intraperitoneal, intramuscular, subcutaneous and oral administrations of MnCl2 in seven-day-old chicks were 21.3 mg kg-1, 28.1 mg kg-1, 28.1 mg kg-1 and...

BACKGROUND AND OBJECTIVES Cognitive control and tonic immobility (TI) have both been implicated in the development of PTSD, but it is not known how these factors are related. The present study investigated if a specific form of cognitive control (attentional control) would moderate the relationship between TI and intrusive memories. METHODS Participants (N = 43) completed the Attentional Cont...

The effects of the male to female mating ratio on the heterophil to lymphocyte ratio and duration of tonic immobility (indicators of stress and fearfulness, respectively) were analyzed in two different experiments with different group sizes. In Experiment 1, four different mating ratios (1:11, 1:5, 1:3, and 1:1) and 10 different Spanish breeds of chickens were used; each breeding pen had 12 bir...

The purpose of the present study was to analyze the effect of a lighting stress on the fluctuating asymmetry (FA), the heterophil-to-lymphocyte ratio, and the tonic immobility duration of chickens. The experiment (440 birds) measured the FA of several traits (outer, middle, inner, and hind toe lengths and leg, wing, second primary feather, and spur lengths), the heterophil-to-lymphocyte ratio, ...

The taiep rat is a myelin mutant in which immobility episodes (IEs) can be induced in adult males by gripping. EEG recordings during gripping-induced IEs show a rapid eye movement (REM) sleep-like pattern, similar to that reported for narcolepsy-cataplexy suggesting that IEs represent a disorder of REM-sleep. An alpha(2) adrenoceptor agonist increases gripping-induced IEs, whereas alpha(2) anta...

Bilateral asymmetry of several morphological traits, tonic immobility reaction, and leucocyte ratio were studied in hens and cocks from four Spanish breeds of chickens (Castellana, Buff Prat, Red Villafranquina, and Barred Red Vasca) and an F2 cross between Castellana and Buff Prat (C x BP - F2). Any two or all three types of bilateral asymmetry (fluctuating asymmetry, directional asymmetry, an...

Traumatization, the operative infliction of a trauma/ traumatic event, may be described as the process(es) through which the criteria of posttraumatic stress disorder (PTSD) are achieved. Trauma or a traumatic event stems from an overwhelming/excruciating bombardment of extreme stress that exceeds individuals' ability to cope, or integrate the cognitive-climate involved with that or those exper...

The influence of beak trimming of two strains of commercial male turkeys (Strains A and B) on behavior during the growing period was investigated. Poults were either left with beaks intact or arc beak trimmed at hatching. Strain by beak treatment interactions were generally lacking, indicating that these two strains responded similarly. Beak trimming did not influence tameness (as measured by r...