Exploring the impacts of a coffin-lying experience on life and death attitudes of medical and nursing students: preliminary findings.

BACKGROUND: Physicians and nurses often exhibit strong negative emotional and behavioral reactions when patients they care for die, and death education helps them cope with these difficulties. When implementing death education, the literature shows that experiential activities are more effective than lecturing, and progressive exposure is the best way to reduce death anxieties. This study examined the effects of coffin-lying, an activity sometimes seen in Asian cultures, on life and death attitudes of medical and nursing students. METHODS: During a period from 2020 to 2021, 134 medical and nursing students from a medical university in northern Taiwan voluntarily participated in this study. Among them, 53 were in the experimental group, who participated in a coffin-lying activity for nearly 3 hours, and the other 81 were in the control group. All participants filled out questionnaires 1 week before the activity (T1), 1 week after the activity (T2), and 6 ~ 11 weeks after the activity (T3). Three waves of data were analyzed by a repeated-measure multivariate analysis of variance (MANOVA). RESULTS: The effects of "love and care" and "feeling of existence" were only manifested at T2, however, the scores of "fear of death" and "death avoidance" between the experimental and control groups significantly differed at T2 and T3. In addition, there were no significant differences between the experimental and control groups in "neutral acceptance", "approach acceptance", or "escape acceptance". CONCLUSIONS: The coffin-lying activity based on desensitization was effective in improving "fear of death" and "death avoidance", and the effects were sustained to 6 ~ 11 weeks. Coffin-lying is not only a well-designed activity that quickly reduces negative tendencies toward death, but it is also worth adopting by medical and nursing schools to make death education more comprehensive.

Analysis of lateral orbitofrontal cortex activation on acquisition of fear extinction and neuronal activities in fear circuit.

Inappropriate fear expression and failure of fear extinction are commonly seen in patients with post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD). Among the patients, aberrant and asymmetric activation of the lateral orbitofrontal cortex (lOFC) is reported in some clinical cases. In this study, we aimed to examine the role of lOFC activation in extinction acquisition and explore the potential functional lateralization of lOFC on extinction. We bilaterally or unilaterally activated the lOFC with N-methyl-D-aspartate (NMDA) before fear extinction acquisition in rats. Our data suggested that both left and bilateral lOFC activation interfered with the in-session expression of conditioned fear, whereas activation of the right lOFC did not. In addition, pre-extinction unilateral or bilateral activation of the lOFC, regardless of the side, impaired the acquisition of fear extinction. We also quantified the neuronal activities during the late phase of extinction with immunohistochemical approach. Our data showed that activation of the lOFC increased the neuronal activities on the injection side(s) in the medial prefrontal cortex (mPFC), the lateral amygdala (LA), the basolateral amygdala (BLA; preferentially the non-GABAergic neurons), and the medial intercalated cells (mITC; preferentially the right side). To conclude, aberrant activation of the lOFC during extinction disturbed the excitatory/inhibitory balance of neuronal activities in fear-related brain regions, which interfered with the expression of conditioned fear and impaired the acquisition of fear extinction.

Impacts of a gross anatomy laboratory course on medical students' emotional reactions in Taiwan: the role of high-level emotions.

BACKGROUND: Gross anatomy laboratory course at medical school is usually an important learning subject for medical students; however, seeing a cadaver often makes them feel uncomfortable. According to the broaden-and-build theory, positive emotions broaden our inventory of thoughts and actions, and build physical, mental, and social resources. Research on positive psychology found that through direct thanks and positive reframing, people who feel gratitude show fewer depressive symptoms. The present study tried to reduce students' negative emotions towards cadavers by sequential activities, such as family interviews and an initiation ceremony, which induced gratitude and other positive emotions. METHODS: The Emotional Reactions Towards Cadavers Scale (ERTCS) was used to evaluate medical students' emotional reactions after they see a cadaver. Third year medical students (n = 105) at Taipei Medical University in northern Taiwan completed ERTCS on three occasions within a single semester during academic year 2016. Repeated-measures ANOVA and hierarchical regression analyses were then conducted to identify any changes in the emotional reactions of these students. RESULTS: The ERTCS showed satisfactory internal consistency and a three-factor structure, i.e., negative emotions, high-level emotions, and excited emotions. High-level emotions were the highest, and negative emotions were the lowest among the three in our sample. Three-wave data showed that participants' high-level emotions increased, negative emotions decreased, and the former simultaneously predicted the latter after controlling for the influence of gender, religious beliefs, experience of the death of a family member or friend, and burnout level. CONCLUSIONS: While past research usually focused on coping strategies to reduce medical students' negative emotions, our study supported the broaden-and-build theory, which emphasizes positive emotions, and demonstrated that elevating medical students' gratitude to 'silent mentors' is an effective way. It is suggested that combining dissection courses with medical humanities can help students successfully handle negative emotions during a gross anatomy laboratory course.

Somite Compartments in Amphioxus and Its Implications on the Evolution of the Vertebrate Skeletal Tissues.

Mineralized skeletal tissues of vertebrates are an evolutionary novelty within the chordate lineage. While the progenitor cells that contribute to vertebrate skeletal tissues are known to have two embryonic origins, the mesoderm and neural crest, the evolutionary origin of their developmental process remains unclear. Using cephalochordate amphioxus as our model, we found that cells at the lateral wall of the amphioxus somite express SPARC (a crucial gene for tissue mineralization) and various collagen genes. During development, some of these cells expand medially to surround the axial structures, including the neural tube, notochord and gut, while others expand laterally and ventrally to underlie the epidermis. Eventually these cell populations are found closely associated with the collagenous matrix around the neural tube, notochord, and dorsal aorta, and also with the dense collagen sheets underneath the epidermis. Using known genetic markers for distinct vertebrate somite compartments, we showed that the lateral wall of amphioxus somite likely corresponds to the vertebrate dermomyotome and lateral plate mesoderm. Furthermore, we demonstrated a conserved role for BMP signaling pathway in somite patterning of both amphioxus and vertebrates. These results suggest that compartmentalized somites and their contribution to primitive skeletal tissues are ancient traits that date back to the chordate common ancestor. The finding of SPARC-expressing skeletal scaffold in amphioxus further supports previous hypothesis regarding SPARC gene family expansion in the elaboration of the vertebrate mineralized skeleton.

The Reuniens and Rhomboid Nuclei Are Required for Acquisition of Pavlovian Trace Fear Conditioning in Rats.

The reuniens (Re) and rhomboid (Rh) nuclei (ReRh) of the midline thalamus interconnects the hippocampus (HPC) and the medial prefrontal cortex (mPFC). Several studies have suggested that the ReRh participates in various cognitive tasks. However, little is known about the contribution of the ReRh in Pavlovian trace fear conditioning, a procedure with a temporal gap between the conditioned stimulus (CS) and the unconditioned stimulus (US), and therefore making it harder for the animals to acquire. Because the HPC and mPFC are involved in trace, but not delay, fear conditioning and given the role of the ReRh in mediating this neurocircuitry, we hypothesized that ReRh inactivation leads to a learning deficit only in trace conditioning. In a series of experiments, we first examined the c-Fos expression in male Long-Evans rats and established that the ReRh was recruited in the encoding, but not the retrieval phase, of fear memory. Next, we performed behavioral pharmacology experiments and found that ReRh inactivation impaired only the acquisition, but not the consolidation or retrieval, of trace fear. However, although the ReRh was recruited during the encoding of delay fear demonstrated by c-Fos results, ReRh inactivation in any phases did not interfere with delay conditioning. Finally, we found that trace fear acquired under ReRh inactivation reprised when the ReRh was brought off-line during retrieval. Together, our data revealed the essential role of the ReRh in a learning task with temporally discontinuous stimuli.

Effects of a "silent mentor" initiation ceremony and dissection on medical students' humanity and learning.

OBJECTIVES: Many medical schools in Taiwan have adopted a dignified "silent mentor" initiation ceremony to strengthen student's medical humanity and increase their learning attitudes. This ceremony consists of introductions of the body donor's conduct and deeds, wreath-laying, and a tea party. However, few empirical studies have examined the influences of the ceremony and dissection on medical humanity. This study explored if the initiation ceremony and the course can help students care more about others, develop more positive attitudes toward death, improve learning effectiveness in the course, and decrease negative emotions the first time they see a cadaver. METHODS: The Attitudes Towards Death and Love and Care subscales of the life attitude inventory, Learning Effectiveness of Gross Anatomy Laboratory Scale (LEGALS), and Emotional Reactions Towards Cadavers Scale were adopted to examine differences before (T1) and after (T2) medical students attended an initiation ceremony at a university in northern Taiwan. Whether these effects lasted to the end of the semester (T3) was also tested. RESULTS: After the ceremony, students' attitudes towards death increased, negative emotions towards cadavers decreased, but love and care and the LEGALS did not significantly change. Data from T3 showed a similar pattern, but high-level emotions (e.g., being respected, cherished, and grateful) and the LEGALS were significantly higher than those at T1. DISCUSSION: The initiation ceremony, which showed a body donor's deeds and attitudes toward life and death when they were alive, could help medical students gain more mature attitudes towards death and decreased negative emotions. Learning between T2 and T3 might have caused significant changes in high-level emotions and the LEGALS at T3. Arranging reflective writing with guided discussion by a teacher before and after the ceremony is highly recommended.

Comprehensive Application of Time-of-flight Secondary Ion Mass Spectrometry (TOF-SIMS) for Ionic Imaging and Bio-energetic Analysis of Club Drug-induced Cognitive Deficiency.

Excessive exposure to club drug (GHB) would cause cognitive dysfunction in which impaired hippocampal Ca(2+)-mediated neuroplasticity may correlate with this deficiency. However, the potential changes of in vivo Ca(2+) together with molecular machinery engaged in GHB-induced cognitive dysfunction has never been reported. This study aims to determine these changes in bio-energetic level through ionic imaging, spectrometric, biochemical, morphological, as well as behavioral approaches. Adolescent rats subjected to GHB were processed for TOF-SIMS, immunohistochemistry, biochemical assay, together with Morris water maze to detect the ionic, molecular, neurochemical, and behavioral changes of GHB-induced cognitive dysfunction, respectively. Extent of oxidative stress and bio-energetics were assessed by levels of lipid peroxidation, Na(+)/K(+) ATPase, cytochrome oxidase, and [(14)C]-2-deoxyglucose activity. Results indicated that in GHB intoxicated rats, decreased Ca(2+) imaging and reduced NMDAR1, nNOS, and p-CREB reactivities were detected in hippocampus. Depressed Ca(2+)-mediated signaling corresponded well with intense oxidative stress, diminished Na(+)/K(+) ATPase, reduced COX, and decreased 2-DG activity, which all contributes to the development of cognitive deficiency. As impaired Ca(2+)-mediated signaling and oxidative stress significantly contribute to GHB-induced cognitive dysfunction, delivering agent(s) that improves hippocampal bio-energetics may thus serve as a promising strategy to counteract the club drug-induced cognitive dysfunction emerging in our society nowadays.

Spatiotemporal Changes of Neuronal Responses in the Primary Somatosensory Cortex to Noxious Tail Stimulation in Awake and Pentobarbital-Anesthetized Rats.

Primary somatosensory cortex (SI) is a key area in the processing of nociceptor inputs to our consciousness. To clarify the columnar and laminar organization of SI for pain processing, we compared spatiotemporal changes in neuronal activities of the primary sensorimotor cortex (SmI) of the rat in response to noxious laser heat stimulation applied to the mid-tail. Longitudinal and vertical array microelectrodes were chronically implanted in the cerebral cortex. Evoked neuronal activities, including intracortical local field potentials (LFP) and ensemble single-unit activity (SU) around SmI were simultaneously recorded. The effect of pentobarbital on the neuronal responses was evaluated in comparison with the neuronal responses in conscious animals to explore the potential substrate of nociceptive processing in the conscious state. The results from the experiment with longitudinal microelectrode arrays indicated that noxious stimulation induced a neuronal response which was spread widely around the SmI of the conscious rat, and the range of neuronal responses was limited to the tail region of the SmI under anesthesia. The results from the experiment with vertical microelectrode arrays showed the universal neuronal responses through all cortical layers of the SmI in conscious rats, and sodium pentobarbital suppressed these neuronal responses in the supragranular layers significantly relative to the deeper layers and basal activity. These results imply that a wider range of cortical activation, both in the horizontal or vertical dimension, might be important for nociceptive processing in the conscious state.

Comparisons of terminal densities of cardiovascular function-related projections from the amygdala subnuclei.

The amygdala is important in higher-level control of cardiovascular functions. In this study, we compared cardiovascular-related projections among the subnuclei of the amygdala. Biotinylated dextran amine was injected into the central, medial, and basolateral nuclei of the amygdala, and the distributions and densities of anterograde-labeled terminal boutons were analyzed. We found that the medial, basolateral, and central nuclei all had projections into the cardiovascular-related areas of the hypothalamus. However, only the central nucleus had a significant direct projection into the medulla. By contrast, the medial nucleus had limited projections, and the basolateral nucleus had no terminals extending into the medulla. We concluded that the medial, central, and basolateral nuclei of the amygdala may influence cardiovascular-related nuclei through monosynaptic connections with cardiovascular-related nuclei in the hypothalamus and medulla.

Involvement of the periaqueductal gray in the effect of motor cortex stimulation.

Several clinical and animal studies of different pain models reported that motor cortex stimulation (MCS) has an antinociceptive effect. In our previous study, the response of the primary somatosensory cortex (SI) to peripheral stimuli decreased after MCS. The aim of the present study was to investigate involvement of the periaqueductal gray (PAG) in this inhibitory effect of MCS. Responses of the SI to electrical stimuli applied to both forepaws of anesthetized rats were monitored to evaluate the effect of MCS. After sensory-evoked potentials (SEPs) were stable, either saline, opioid, or dopamine receptor antagonists were locally microinjected into the PAG. After drug or saline administration, MCS was applied to the forepaw area of the right motor cortex. SEPs after MCS were compared to those before MCS. In the saline group, SEPs ipsilateral to MCS decreased, but SEPs contralateral to MCS did not. The decrease in SEPs was prevented by pretreatment of the PAG with naloxone. Application of a nonspecific dopamine receptor antagonist (α-flupenthixol) to the PAG also blocked the inhibition of SEPs after MCS. Inhibition of SEPs after MCS was blocked by local application of a D1 antagonist (SCH-23390) in the PAG, but not by a D2 antagonist (eticlopride). These results suggest that the PAG participates in the inhibitory effect of MCS, and this effect of MCS may be mediated by opioid and dopamine D1 receptors within thePAG.

Epidural motor cortex stimulation suppresses somatosensory evoked potentials in the primary somatosensory cortex of the rat.

Motor cortex stimulation (MCS) is a promising clinical procedure to help alleviate chronic pain. Animal models demonstrated that MCS is effective in lessening nocifensive behaviors. The present study explored the effects of MCS on cortical somatosensory evoked potentials (SEPs) recorded at the primary somatosensory cortex (SI) of the rat. SEPs were evoked by electrical stimulation applied to the contralateral forepaws. Effects of different intensities, frequencies, and durations of MCS were tested. MCS at ≥2V suppressed SEPs of the ipsilateral SI. Suppression lasted 120 min at an intensity of 5 V. The optimal frequency was 50 Hz, and the duration was 30s. In contrast, MCS did not affect SEPs recorded on the contralateral SI. Cortical stimulation out of the motor cortex did not induce a decrease in the ipsilateral SEPs. We also investigated involvement of the endogenous opioid system in this inhibition of SEPs induced by MCS. The opioid antagonist, naloxone (0.5 mg/kg), was administered 30 min before MCS. Application of naloxone completely prevented the inhibitory effect of MCS on ipsilateral SEPs. These results demonstrate that MCS blocked the transmission of somatosensory information to the primary somatosensory cortex, and this interference was mediated by the endogenous opioid system. This inhibitory effect on sensory transmission induced by MCS may reflect its antinociceptive effect.

Differential involvement of the anterior cingulate and primary sensorimotor cortices in sensory and affective functions of pain.

The present study examined the role of neurons in different pain-related functions of the anterior cingulate cortex (ACC) and primary sensorimotor cortex (SmI) by assessing their abilities to code different levels of noxious heat and activity changes evoked by classical fear conditioning involving electric shocks. Multiple single-unit activity was recorded with microwires implanted in the SmI and ACC of each rat. In the first set of experiments, the middle segment of the tail in each rat was irradiated with laser-heat pulses of various intensities. Neuronal responses in both the SmI and ACC increased with the intensity of the laser heat, although there was a significantly higher percentage of intensity-related units in the SmI. Furthermore, the stimulus-response curve of SmI ensemble activity had a steeper slope than that of the ACC. In the second set of experiments, rats were trained and tested on a conditioned fear-potentiated startle task in which a light was paired with an electric shock and, later, the startle response was elicited by a burst of noise in the presence or absence of light. A higher percentage of ACC units changed their neuronal responses to the conditioned stimulus after the light-shock pairing and the average activity change was also significantly stronger. Our results suggest that SmI neurons are better at coding laser-heat intensity than ACC neurons, whereas more ACC neurons are involved in conditioned fear associated with an electric shock than SmI neurons. These data provide evidence for differential contributions of the SmI and ACC to sensory and affective dimensions of pain.

State-dependent amygdala stimulation-induced cardiovascular effects in rats.

Stimulation of the amygdala is known to produce pressor, depressor, or has no effects. The present study was performed to test whether amygdala cardiovascular effects are influenced by consciousness states and by different types of anesthetics. Adult rats were set up for stimulation amygdala and measurement of blood pressure in a chronic preparation. After recovery, same sites of the amygdala were stimulated electrically for several trials with the rat under conscious or anesthetic states induced by pentobarbital, urethane, ketamine, alpha-chloralose and urethane plus alpha-chloralose, respectively. The interval between any two stimulation trials was at least 2 days. The stimulation was an 80-Hz, 0.5-ms, 100-micro A square wave pulse train lasting for 15 s. Cardiovascular responsive sites were found in the central, medial, and basolateral nuclei of the amygdala. In stimulating these responsive sites, significantly different cardiovascular effects were induced under a conscious state and an anesthetized state of the animal, yet no significant differences were found among the various anesthetic agents. We conclude, that the cardiovascular influence of the amygdala is state-dependent in the rat.