Dissociation of physiology and behavior in PTSD.

We have previously reported that subjects with posttraumatic stress disorder (PTSD) differ from trauma controls in their ability to produce and withhold responses in the Stop-Signal Task depending on the motivational context as determined by financial reward. This experiment measured skin conductance and heart rate to assess autonomic changes accompanying these different patterns of behavior. Fowles hypothesized that heart rate would increase with behavioral activation and that increases in skin conductance would accompany behavioral inhibition. Both PTSD and comparison groups showed the expected behavioral changes in response to rewards, but they differed in their physiological responses. The subjects in the traumatized comparison group showed changes in skin conductance and heart rate consistent with Fowles' hypothesis and the observed changes in behavioral inhibition and activation. However, PTSD subjects showed no significant change in either physiological measure. These results demonstrate a dissociation between autonomic reactivity and motivated behavior in PTSD that may represent one aspect of emotional numbing.

Olanzapine treatment for post-traumatic stress disorder: an open-label study.

Post-traumatic stress disorder (PTSD) is a common and increasingly diagnosed mental illness. Recent pharmacotherapeutic research on treatments for this condition has focused on antidepressant drugs with serotonergic actions. However, the presence of intrusive, psychotic-like symptoms in a substantial portion of PTSD patients raises the possibility that antipsychotics with serotonergic properties might also prove useful in treating PTSD. We conducted an open-label 8-week study of olanzapine treatment in veterans with combat-induced PTSD. Primary outcome measures in this study were the Clinician Administered PTSD Scale (CAPS) and the Clinical Global Impressions Improvement scale. Secondary outcome measures included the Hamilton Rating Scales for Depression (HRSD) and Anxiety (HRSA). Forty-eight patients enrolled in the study, and 30 completed the 8-week trial. Results of intent-to-treat and completer analyses demonstrated that all outcome measures improved significantly during treatment. Secondary analyses indicate that improvement in the intrusive symptom cluster of the CAPS was independent of improvement on the HRSD and HRSA. In conclusion, the study indicates that olanzapine treatment is useful in alleviating the symptoms of combat-induced PTSD.

Psychophysiologic responsivity in posttraumatic stress disorder: generalized hyperresponsiveness versus trauma specificity.

BACKGROUND: Clinically, subjects with posttraumatic stress disorder (PTSD) are viewed as hyperresponsive to a variety of stimuli. Psychophysiologic studies, however, have demonstrated hyperresponsiveness only to stimuli that are closely related to the original trauma. METHODS: This set of experiments uses a variety of stimuli that vary in trauma-relatedness, arousal level, sensory modality stimulated, and degree of cognitive processing demanded to assess the extent of generalization of physiologic responses. Heart rate (HR), frontal electromyogram (EMG), and skin conductance (EDG) responses were measured during presentation of each stimulus. RESULTS: PTSD subjects (n = 15) had an elevated baseline EDG and increased HR and EMG responses to the trauma-related stimulus (combat sounds) compared to normal control subjects (n = 11) and combat control subjects (n = 10). No significant differences were noted between PTSD and control groups in response to non-trauma-related arousing stimuli. CONCLUSIONS: These results suggest that the physiologic hyperresponsivity of PTSD subjects is limited to stimuli closely associated with the inciting trauma.

An investigation of dental student values.

The development of a dental student's professional values system is an important issue in dental education. The purpose of this study was to assess the relative importance of different values of dental student and instructor populations at a single dental school. Data was collected from surveys disseminated to dental students and faculty. Statistical analysis of the data indicated faculty showed a different set of values than students. Faculty placed greater value on patient care and clinical education. Students were more focused on passing licensure examinations, completing course requirements, and personal satisfaction. Junior and senior dental students placed greater value on the requirements of becoming a licensed dentist than did their younger student colleagues. Freshman and sophomore dental students placed higher values on additional academic pursuits and personal growth. This study also revealed no statistically significant difference between males and females in any of the values ranked.

Muscarinic receptors mediate the effect of acetylcholine (ACh) on neurons of the bed nucleus of the stria terminalis (BNST).

This study was designed to determine the type of receptor mediating the effect of ACh on BNST neurons. 45% of BNST neurons showed a dose-dependent monophasic increase in firing rate in response to ACh. Muscarinic antagonist blocked the effects of ACh. Amygdala stimulation (Amyg S) elicited excitatory responses, but atropine and hexamethonium had no effect on the Amyg S induced excitation. The experiment shows that the excitatory effect of ACh on BNST neurons is mediated by muscarinic receptors, while the excitatory effects of Amyg S on BNST neurons is not mediated by ACh.

Responses of neurons in bed nucleus of the stria terminalis to microiontophoretically applied morphine, norepinephrine and acetylcholine.

The bed nucleus of the stria terminalis is a basal forebrain nucleus that receives inputs from limbic system nuclei and sends projections to several hypothalamic and brainstem nuclei, proposed to be involved in the physiological response to stressors. The bed nucleus of the stria terminalis also receives norepinephrine- (NE), acetylcholine- (ACh) and opiate-containing projections. The objectives of this experiment were to examine the effects of microiontophoretically applied ACh, NE and morphine sulfate (M) on neurons of the bed nucleus in urethane-anesthetized rats and to determine the degree to which these systems interact on individual neurons. Acetylcholine was excitatory in 43% of the neurons and NE was inhibitory in 70%. Morphine however, elicited two distinct types of response--excitation in 24% of the neurons and inhibition in 28%. Each of these effects was current-dependent and monophasic. Since 77% of neurons of the bed nucleus responded to two or more of the drugs used in this experiment, statistical analysis was used to determine correlations between responses to each of these drugs. This analysis showed that neurons that responded to M with excitation also responded to ACh with excitation, while neurons that responded to M with inhibition, were nonresponsive to ACh. No correlation was found between NE and either M or ACh. Thus, this experiment demonstrated the possible effects of noradrenergic, cholinergic and opioid innervation on firing rates of neurons of the bed nucleus of the stria terminalis and may explain the roles these neurotransmitters play in modulating the response to stress.

Evidence for two different afferent pathways carrying stress-related information (noxious and amygdala stimulation) to the bed nucleus of the stria terminalis.

The bed nucleus of the stria terminalis (BNST) is an important nucleus involved in mediating amygdala-regulated endocrine effects. Since the amygdala is important in mediating the endocrine response to noxious somatosensory stimuli and olfactory stimulation, this experiment studies whether noxious input (tail pinch, TP) and stress-related input (amygdala stimulation, AmygS) will modulate BNST neuronal activity. One hundred and fifty-eight BNST neurons were studied following AmygS, TP and cutaneous stroke. AmygS was effective in 66% of BNST neurons and produced one of the following five responses: oligosynaptic excitation (43%), polysynaptic excitation (5%), time-locked inhibition (4%), generalized increase in firing rate (8%), or generalized decrease in firing rate (6%). TP produced an increase in firing rate in 27% of BNST neurons tested. Analysis of a contingency table constructed to determine the degree of correspondence between neurons responsive to AmygS and neurons responsive to TP showed that the distributions of reactivity to these stimuli in BNST neurons are independent of each other. This suggests that although AmygS and TP are both capable of altering the firing rate of BNST neurons, the pathways by which they reach BNST differ.

Dental emergencies: management in the long-term care facility.

In an extended care facility, the nurse may be the first health care professional to become aware of a dental emergency. A systematic approach to the evaluation and resolution of dental emergencies is presented.

Restraint and stimulation of bed nucleus of the stria terminalis produce similar stress-like behaviors.

Restraint stress, electrical stimulation of the bed nucleus of the stria terminalis (BNST), and the combination of restraint stress and BNST stimulation were studied using a computerized animal activity monitoring system. Both restraint and the combination of restraint and BNST stimulation produced increases in locomotor, exploratory and stereotypic activity all of which returned to baseline within an hour while BNST stimulation alone also increased measurements of locomotor and exploratory behavior some of which remained elevated throughout the three-hour period of measurement. BNST stimulation also produced vigorous escape behavior and biting which were not seen with restraint alone. Thus electrical stimulation of BNST produces behavior which is qualitatively similar to the behavior produced by stress but differs in time course.

Dental care for a patient with Alzheimer's disease. A case report.

Alzheimer's disease, a devastating, irreversible and progressive degenerative disease of unknown cause or cure, is the fourth leading cause of adult death. With a predicted increase in the proportion of the population age 65 or older anticipated, the incidence of Alzheimer's disease should rise. As a result, more Alzheimer's patients will be seen in the dental office. A case report illustrating the skills and techniques necessary to treat a patient with Alzheimer's disease is presented.

Restraint stress modulates sensory evoked potentials.

The present experiment investigated whether repeated exposure to an acute stressor elicits changes in sensory evoked responses recorded from awake rats. Animals were restrained for four hours per day on each of four consecutive days. Recordings were obtained on the day prior to the first restraint and following the first and fourth day of restraint. Restraint generally resulted in an increase in the amplitude of sensory evoked responses recorded from the medial basal hypothalamus (MBH), dorsal hippocampus (DH), and superior colliculus (SC) without changing any other characteristics of the recording. A persistent increase in the averaged evoked response amplitudes seen on both the first and fourth daily presentation of the stressor indicates that no significant adaptation to the stressor occurred over this time period as measured electrophysiologically.

Interrelationships among epidermal Na-K ATPase, developmental stage and length of Rana catesbeiana tadpoles.

Sodium and potassium activated adenosine triphosphatase (Na-K ATPase) was extracted from the skin of Rana catesbeiana tadpoles and adults. Using carefully staged tadpoles, it was noted that the enzyme level increases two or three stages before there is a perceptible potential difference generated across the skin. The level of non-ouabain-inhibitable ATPase remains constant throughout the life cycle. It was also concluded that Rana catesbeiana tadpoles cannot be reliably staged using length as a key trait.