Biomedical subjects

Deborah Saucier

Publications and source records attributed to Deborah Saucier.

5 recordsLinked to original sources

PubMed2004

Febrile convulsions affect ultrasonic vocalizations in the rat pup.

Febrile convulsions are common among preschool children and are studied experimentally with hyperthermia in rat pups. Although heat-induced convulsions (HC+) can affect behaviors in adulthood, to date no one has examined the effects on behavior in the neonatal period. We examined the effects of HC+ on ultrasonic vocalizations (USVs) and mother-pup interactions in P10- and P12-aged rat pups. On P7, 34 pups were subjected to HC+ (32 controls, HC-) and behaviors were observed on P10 and P12. For mother-pup interactions, a trend for a sex x treatment interaction was found, with HC- females and HC+ males interacting more often with their dam. Further, HC+ pups vocalized more than controls (HC-) and male pups vocalized more than females. Interestingly, females and HC+ pups displayed less efficient USVs. However, mother-pup interactions did not significantly differ between HC+ and HC- pups, despite greater vocalization. Thus, dams differentiate among their pups, perhaps through USVs.

Animals↗

PubMed2003

Water self-diffusion tensor changes in an avian genetic developmental model of epilepsy.

Diffusion tensor imaging (DTI) was used to investigate whether tissue anisotropy in the developing brain is modified by recurrent seizures in epileptic chickens. Twelve epileptic chickens were sorted equally into two experimental groups at 10 days old. Until the age of 180 days, one group was photically stimulated beginning at an age of 2 weeks and repeated every 2 days while the other group was not stimulated. The photic stimulation induced generalized tonic-clonic seizures, and the unstimulated group did not display seizures. Both treatment groups were imaged at three time points, 45 (juvenile), 90 (adolescent), and 180 (adult) days posthatching, and maps of major and minor elements of anisotropy (eta and epsilon), trace and fractional anisotropy (FA) were generated. The eta, epsilon, and trace values in the hyperstriatum, archistriatum, and optic tectum showed significant changes as a function of developmental time point. Differences and/or interactions due to seizures were seen in the archistriatum and optic tectum for eta, epsilon, and trace with the largest differences between the stimulated and unstimulated birds being seen for eta in juvenile birds in the archistriatum (38.1 x 10(-11) m(2)/s versus 18.0 x 10(-11) m(2)/s) and the optic tectum (53.9 x 10(-11) m(2)/s versus 27.1 x 10(-11) m(2)/s). With the DTI parameters being sensitive to microstructure in the brain, these results demonstrate that seizures produce measurable differences, over unstimulated chickens, in brain structure for juvenile chickens, but the differences disappear as the brain matures. In other words, while seizure activity appears to induce atypical biophysical change (relative to unseizing birds) in the brain at a young age, the change is apparently reversed as the brain matures.

Adaptation, Physiological↗

PubMed2003

Males and females scan maps similarly, but give directions differently.

After studying routes on a map, females tend to give directions that feature landmarks and left/right turns, whereas males include more cardinal and distance information. It is plausible this difference results from disparate attention to these features during exploration of a map. In the present study, 22 males and 22 females learned routes on a map while their eye movements were monitored, and then gave written directions between different locations. Consistent with earlier research, males made more references to NSEW when giving directions, whereas females referred mainly to left/right turns and landmarks along each route. However, these reporting biases were not related to differences in how the groups explored the maps, as females did not spend more time looking at landmarks, nor did either group spend more time looking at Euclidean cues. Thus, despite sexually dimorphic route descriptions, there was not dimorphic exploration or attention to the salient features.

Adolescent↗

PubMed2003

Sex differences in the effect of articulatory or spatial dual-task interference during navigation.

Women are more likely to employ landmark-based strategies when navigating, and they are superior at employing this type of strategy. The cause of this sexually dimorphic behaviour is unknown. Seventy-nine undergraduates performed a matrix navigation task wherein the symbols within the matrix were highly nameable. Participants were either given landmark-based or Euclidean-based instructions for navigation within the matrix. During navigation, participants were subjected to either articulatory or spatial interference. The articulatory interference selectively impaired women's ability to navigate correctly, regardless of the type of instruction. The performance of the men was not affected differentially by the two types of interference. When given a test of symbol recognition following the navigation task, women recognized more of the symbols employed in the task. Collectively, this result suggests that women rely on linguistic information more than men do when navigating, regardless of the type of instruction.

Adult↗

PubMed2003

Female advantage for spatial location memory in both static and dynamic environments.

A female advantage has previously been found for spatial location tests of object memory. Previous studies have used static, 2-D tasks to test this advantage. This study used a computerized adaptation of the game Concentration to test object location memory in both a static and dynamic array of 24 pairs of line drawings. The dynamic version of this task was used to better reflect the dynamic real world in which we usually use object location memory. Consistent with previous research, we observed a female advantage. This advantage was found to a similar extent in both the static and dynamic versions of the task. The female advantage for object location memory is a concrete advantage in spatial cognition that females show on the Concentration Task, regardless of the nature of the presentation environment.

Adult↗