Biomedical subjects
Publications and source records attributed to J S Janowsky.
An epileptic girl with Lennox-Gastaut syndrome had seizures triggered specifically by blinking, but not by other eye movements or by photic stimulation. Electrographic and clinical seizures were most reliably precipitated by repetitive blinking produced voluntarily on command, by reflex blinking on corneal stimulation, or by psychogenic triggers of blinking such as social stress or cognitive effort.
The hippocampus, dentate gyrus, cerebellum, amygdala and caudate were examined for degenerating cells in normal neonatal hamsters. Each structure was studied from postnatal day 5 (P5) to P 10. The cerebellum was also studied on P 12. This time span was chosen to coincide with cessation of migration and establishment of connectivity in these structures. Substantial numbers of pycnotic cells were found in all structures except the dentate gyrus. The timing and amount of cell death varied between structures. Both the caudate nucleus and the amygdala showed greater cell losses in their peripheral margins than in their centers. The deep half of the internal granule cell layer of the cerebellum showed greater cell loss than the superficial half on all postnatal days studied.
Hypothermia was studied 5 min before, and 30 and 60 min after intraperitoneal administration of ethanol (3 g/kg) in 20 inbred strains of mice. Ethanol was given daily for 8 days, and temperatures were taken on Days 1, 3, 5, and 8. Tolerance was indexed by the reduction in hypothermia over days. There were large strain differences in baseline temperature, the hypothermic effect of ethanol, and in development of tolerance to hypothermia. Some strains of mice (DBA/1J, DBA/2N, MA/MyJ, and PL/J) did not develop tolerance to the hypothermic effect of ethanol. Initial sensitivity to the hypothermic effect of ethanol was significantly genetically correlated with tolerance development, indicating control of these responses by common genes. Ethanol-induced changes in activity and ataxia, as well as blood ethanol concentrations, were also assessed. Although there were significant strain differences in activity reduction, ataxia, blood-ethanol concentrations, and changes in these parameters during the course of chronic treatment, none of these variables could explain the genetic differences in hypothermic sensitivity and tolerance.
Explore the source record for details and available documents.
As a model of reflex epilepsy, rats were classically conditioned to show paroxysmal spike activity to an auditory stimulus. A tone stimulus was paired with seizures induced by kindling. After repeated pairings, paroxysmal discharges were elicited at tone onset. The duration of the tone, proximity to the stimulation, and the number of pairings appeared to be important in the conditioning process.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The present study examined sex differences in the area and age-related atrophy of the corpus callosum (CC) of 76 healthy elderly subjects using magnetic resonance imaging. The cerebellum and pons served as noncortical control structures. CC area and its subregions were also related to cognitive performance. Women had a slightly larger posterior sector of the CC than men. Women but not men showed age-related atrophy of the anterior and middle sectors of the CC but not the posterior sector. Cerebellum and pons size was similar in men and women, and neither showed age-related atrophy. CC area was related to visual memory in women but not men; no other significant cognitive to structure area relationships were found. These findings show that selective age related atrophy of the CC differs in men and women late in life.
We used volumetric magnetic resonance imaging to examine sex differences in prefrontal tissue volumes of healthy aged and patients with Alzheimer's disease (AD). Healthy subjects had greater total prefrontal volume than AD, and men had greater total prefrontal volume than women (ps < or = 0.02). This was true for both gray and white matter volumes. There were no interactions between group and sex for total prefrontal volume. An exploratory analysis of each group suggested that sex differences in both gray and white matter in healthy aging are not sustained in AD.
Male mice of parent inbred strains C57BL/6J and DBA/2J, and mice from several of the BXD/Ty Recombinant Inbred (RI) strains derived from the cross of the parent inbred strains were tested for responsiveness to ethanol. Separate groups of mice from these strains were characterized for sensitivity to ethanol's effects to increase activity in an open field and to induce ambulatory ataxia in the grid test. The strain distribution pattern of the RI strains indicated polygenic control of both responses to ethanol. Other mice from this battery were tested for acceptance of an ethanol solution, a measure related to preference drinking. This trait may be substantially influenced by a single gene. Mice were then rendered physically dependent on ethanol through inhalation of ethanol vapor for three days. Severity of handling-induced convulsions was used to index the severity of the ethanol withdrawal syndrome. The distribution of the RI strains indicated possible influence of a major gene on ethanol withdrawal severity.