Chronic active myocarditis following acute Bartonella henselae infection (cat scratch disease).

An association between Bartonella infection and myocardial inflammation has not been previously reported. We document a case of a healthy young man who developed chronic active myocarditis after infection with Bartonella henselae (cat scratch disease). He progressed to severe heart failure and underwent orthotopic heart transplantation. Bartonella henselae, therefore, should be included among the list of infectious agents associated with chronic active myocarditis.

Effects of the serotonin receptor agonists 8-OH-DPAT and TFMPP on learning as assessed using a novel water maze.

We evaluated the effects of two drugs active at serotonin receptors, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, a 5-HT1A agonist) and N-3-trifluoromethylphenyl)piperazine hydrochloride (TFMPP, a 5-HT2C agonist) on learning using a novel water maze previously characterized in our laboratory. The water maze utilized is a traditional type of maze with alleyways and doors through which the rats learn to swim to reach a platform, unlike the open pool Morris water maze task. Performance is assessed by swim time required to reach the platform and errors committed. Following initial training on maze configuration A, rats were assigned to saline, TFMPP and 8-OH-DPAT treatment groups and tested for performance once per dose, 30 min after administration of drug (0.25, 0.5, and 1.0 mg/kg IP). Swim times were significantly increased as compared to saline for all doses for both drugs. The error rate was increased for 8-OH-DPAT at all doses, while TFMPP had no effect on error rate at any dose. Next, rats were challenged to learn new mazes following daily administration of 0.25 or 0.5 mg/kg of each drug 30 min prior to each daily swim trial. Rats given 0.25 mg/kg of 8-OH-DPAT learned new maze C more slowly than saline-treated rats, while TFMPP had no effect at this dose. At the higher dose of 0.5 mg/kg, tested on new maze B, TFMPP administration significantly increased swim times but not errors, while this dose of 8-OH-DPAT markedly increased both swim time and errors. Finally, rats from all groups were tested on maze E after drug administration was discontinued, and there were no performance differences among groups. These data suggest that serotonin1A receptors may inhibit learning.

Effects of chronic stress on sleep in rats.

The present study was conducted to determine the effects of chronic stress on sleep using a rodent paradigm of around-the-clock signalled intermittent foot shock in which some rats can pull a chain to avoid/escape shock while another group of rats is yoked to the first group. We measured sleep using telemetry; four-channel EEG was collected 24 h/day in rats during 2 prestress days; days 1, 2, 3, 7, and 14 during chronic stress; and 3 poststress days. States of REM sleep, non-REM (NREM) sleep, and waking were scored for each 15-s period of the EEG recordings. During the prestress period, rats slept (REM plus NREM) 55% of available time during the light hours and 34% of the dark hours with the remainder represented by waking. On the first day of stress, total sleep and, especially REM sleep, decreased markedly. By the second day of stress, only REM sleep in the controllable stress group (but not the uncontrollable stress group) was still significantly decreased compared to prestress levels, and REM sleep returned to baseline levels by day 7 of stress. The recovery of sleep quantity was accomplished by increased sleep during the dark hours, resulting in a long-lasting disruption of normal circadian sleep patterning.