Guidelines for best practice in placebo-controlled experimental studies on probiotics in rodent animal models.

In the absence of established best practice standards in the probiotic field for reducing the risk of bacterial transfer between experimental groups, we developed protocols and methods to ensure the highest quality and interpretability of results from animal studies, even when performed in non-conventional animal care facilities. We describe easily implementable methods for reducing cross-contamination during animal housing, behavioural testing, and euthanasia, along with highlighting protocols for contamination detection in experimental subjects and laboratory areas using qPCR. In light of the high cross-contamination risks between animals during experiments involving probiotics, constant vigilance in animal care and research protocols is critical to ensure valid and reliable research findings.

The development of adaptive head movements following enucleation.

Recent work in our laboratory has revealed that enucleated patients produce large lateral and vertical head movements during visually guided grasping. These movements may allow them to maximise the use of retinal motion cues in planning and controlling their grasp. The aim of the present study was to determine whether the tendency to produce these adaptive head movements increases as a function of time since enucleation. We tested a group of 12 enucleated patients in whom the time between surgery and testing varied from 2 weeks to 35 years (mean = 11.2 years). These patients were required to reach out and grasp oblong blocks of different sizes at different distances. Correlational tests revealed an increase in the proportion of self-generated lateral and vertical head movements versus forward head movements as a function of post-enucleation time (r(s)(12) = 0.68, p < 0.025 and r(s)(12) = 0.65, p < 0.025, respectively). This suggests that enucleated patients may be adapting to living with one eye by learning to increase the proportion of their lateral and vertical head movements during the performance of skilled motor acts.

Adapting to monocular vision: grasping with one eye.

The aim of the present study was to determine whether normal subjects with one eye covered and patients in whom one eye had been enucleated generate more head movements than subjects using binocular vision during the performance of a visually guided grasping movement. In experiment 1, 14 right-handed normal subjects were tested binocularly and monocularly in a task in which they were required to reach out and grasp oblong blocks of different sizes at different distances. Although the typical binocular advantage in reaching and grasping was observed, the overall head movement scores did not differ between these testing conditions. In experiment 2, seven right-handed enucleated patients were compared to seven age and sex-matched control subjects (tested under binocular and monocular viewing conditions), on the same task as used in experiment 1. While no differences were found in the kinematics of reaches produced by the enucleated patients and the control subjects, the patients did produce larger and faster resultant head movements, composed mainly of lateral and vertical movements. This suggests that enucleated patients may be generating more head movements in order to better utilize retinal motion cues to aid in manual prehension.