Role of Post-Traumatic Growth in Bereavement Outcomes: An Inquiry of Family Caregivers in Hospice

Background: Family caregivers (FCGs) encounter several physical, psychosocial, and financial struggles while caring for a dying loved one. After their loved one has passed, FCGs face new difficulties as they transition out of the caregiving role and into bereavement. Recent research has focused on the positive adaptive outcomes of bereavement. Objective: This study examined the relationship between core bereavement experiences and post-traumatic growth (PTG) for bereaved hospice FCGs. Design: This is a quantitative cross-sectional mail-in survey. Settings/Subjects: A total of 395 bereaved FCGs of patients who died while under the care of a comprehensive hospice program were surveyed. Measurements: Demographics were collected. Bereavement experiences were assessed using the core bereavement items, and PTG was assessed using the Posttraumatic Growth Inventory (PTGI). Both surveys are validated measures. Results: Two-tailed bivariate correlations were used to analyze the relationships between bereavement experiences and PTG. Significant positive relationships were found between all bereavement experiences and PTG variables (p = <0.01-0.011, r = 0.134-0.290), except for one variable pairing (grief × new possibilities). Participants who reported more intense bereavement experiences also reported greater PTG, especially in the areas relating to others and appreciation of life. Conclusion: FCGs who undergo more intense bereavement experiences tend to experience greater PTG. This information can be used in the future to develop a more comprehensive understanding of the multifaceted nature of grief and loss.

Single Subcutaneous Ketamine Dose Followed by Oral Ketamine for Depression Symptoms in Hospice Patients: A Case Series

Management of depression symptoms in hospice patients is complicated by the fact that an appropriate trial of antidepressant therapy requires 4-6 weeks and most hospice patients receive hospice services for less than 8 weeks. Intravenously administered ketamine has been shown to produce rapid improvement in depression symptoms but is not an ideal route for hospice patients and oral ketamine appears to have a slower onset of antidepressant activity. We present a case series that illustrates the use of a single subcutaneous dose of ketamine (0.5 mg/kg) followed by daily oral ketamine (0.5 mg/kg daily) therapy to manage depression symptoms in three hospice patients. Clinical improvement of depression symptoms occurred quickly for all patients as measured by the PHQ-4, numeric ratings, and subjective reporting. A single subcutaneous dose of ketamine followed by oral therapy presents itself as an option to quickly reduce depression symptoms in hospice patients that do not also require additional pain management. Combining the use of the subcutaneous and oral routes takes advantage of the possibly faster onset, home administration, and milder side effects than intravenous dosing. Prospective studies are needed to determine which dosing strategy would be the most beneficial for hospice patients.

Attitudes and Perceptions of End-of-Life Dreams and Visions and Their Implication to the Bereaved Family Caregiver Experience

BACKGROUND

While the majority of research assesses the impact of end-of-life dreams and visions (ELDVs) on patients, more recent research has begun to explore their impact on family caregivers (FCG).

OBJECTIVE

This study evaluates the relationship between general attitudes about dreams, perspectives of ELDV and their role the bereaved FCG experience.

DESIGN

Mixed-methods using a cross-sectional survey and five focus groups.

SETTINGS/SUBJECTS

A total of 500 FCGs of patients who died under hospice care were recruited for the survey. Focus group members were self-selected through identified interest from the survey.

MEASUREMENTS

In addition to demographics and ELDV prevalence, general attitude toward dreams, ELDV perspectives, and impact on grief were assessed using ad hoc surveys.

RESULTS

Participants reporting ELDVs were significantly more validating of everyday dreams (p < .001). Positive attitudes toward dreams strongly correlated with comfort from ELDVs for both patients and FCGs. Openness correlated positively with comfort from the ELDV for both the patient (r = .149, p = .038) and FCG (r = .217, p = 0.002) and negatively with fear/anxiety (r = -.141, p = 0.050). Negative ELDV perceptions (ex. ELDVs were caused by medications) affected grief in areas such as accepting the loss (r = -.235, p = .010) or maintaining connection (r = -.255, p = .010) with the deceased. Focus group discussions were thematically analyzed resulting in 4 themes: ELDV narrative, Connection, Reflection, and Other Experiences.

CONCLUSIONS

Positive general attitudes toward dreams and positive ELDV perceptions are correlated with better bereavement outcomes. Therefore, patient and family education on ELDVs that focuses on awareness and understanding of ELDVs may enhance clinical outcomes for both family and patients.

Expanding the Understanding of Content of End-of-Life Dreams and Visions: A Consensual Qualitative Research Analysis

Background: Research has established End-of-Life Dreams and Visions (ELDVs) as prevalent, meaningful valid experiences that may help patients cope with illness and approaching death. However, no inductive qualitative analysis has explored the phenomenology of ELDVs from the perspective of hospice homecare patients. Objective: The purpose of this study is to evaluate the content of ELDVs by using a rigorous qualitative approach. Design: Five hundred forty-eight ELDVs were collected from weekly interviews of hospice homecare patients and analyzed by using Consensual Qualitative Research Methodology. Settings/Subject: Participants were enrolled in a county-wide hospice homecare program between January 2013-March 2015. Results: The following domains emerged: (1) Interpersonal, (2) Affective Experience and Reflection, (3) Activities, and (4) Setting/Location. Conclusions: This study suggests that ELDV content may include a broader spectrum of experiences that reflect waking life than previously believed. Clinical implications suggest that it may be important for providers to engage with ELDVs, as they are psychologically significant experiences that may be a source of clinical insight.

Hospice Patient Care Goals and Medical Students' Perceptions: Evidence of a Generation Gap?

BACKGROUND

The ability to perceive care goals of the dying may be an indicator of future quality patient-centered care. Research conducted on end-of-life goals indicates discrepancies between patients and physicians.

OBJECTIVE

The aim of this study is to compare end-of-life care goals of hospice patients and medical student perceptions of patient care goals.

DESIGN

Hospice patients and medical students were surveyed on their care goals and perceptions, respectively, using an 11-item survey of goals previously identified in palliative care literature. Medical student empathy was measured using the Interpersonal Reactivity Index.

SETTINGS/PARTICIPANTS

Eighty hospice patients and 176 medical students (97 first-year and 79 third-year) in a New York State medical school.

RESULTS

Medical students ranked 7 of the 11 care goals differently than hospice patients: not being a burden to family (p < .001), time with family and friends (p = .002), being at peace with God (p < .001), dying at home (p = .004), feeling that life was meaningful (p < .001), living as long as possible (p < .001), and resolving conflicts (p < .001). Third-year students were less successful than first-year students in perceiving patient care goals of hospice patients. No significant differences in medical student empathy were found based on student year.

CONCLUSIONS

Medical students, while empathetic, were generally unsuccessful in perceiving end-of-life care goals of hospice patients in the psychosocial and spiritual domains. Differences impeding the ability of medical students to understand these care goals may be generationally based. Increased age awareness and sensitivity may improve future end-of-life care discussions. Overall, there is a need to recognize the greater dimensionality of the dying in order to provide the most complete patient-centered care.

End-of-Life Dreams and Visions and Posttraumatic Growth: A Comparison Study

Background: End-of-life dreams and visions (ELDVs) can provide both meaning and comfort to individuals nearing death. While research has examined the prevalence and content of ELDVs, little is known on how dreaming at end of life may affect psychological processes. Objective: This study aimed to explore differences in posttraumatic growth (PTG) between hospice patients who experience ELDVs and hospice patients who do not experience this phenomenon. Design: This is a multimethod cross-sectional comparison study. Settings/Subjects: 70 hospice patients (35 with ELDV experiences and 35 without ELDV experiences) were recruited after being admitted to a hospice inpatient unit. Measurements: PTG was assessed using a modified version of the Posttraumatic Growth Inventory (PTGI). Demographic information, ELDV occurrence, and a brief description of ELDVs were also collected. Results: Significant differences emerged between groups in terms of personal strength (p = 0.012), spiritual change (p = 0.002), and overall PTG (p = 0.019). Patients with ELDV experiences had higher scores on all subscales as well as overall PTG compared to nondreaming patients. Conclusions: Dreams and visions at the end of life affect PTG of dying individuals in hospice care. Further research should be conducted between groups to examine the effects ELDVs may have on other psychological processes.

"People don't understand what goes on in here": A consensual qualitative research analysis of inmate-caregiver perspectives on prison-based end-of-life care

BACKGROUND

The age demographic of the incarcerated is quickly shifting from young to old. Correctional facilities are responsible for navigating inmate access to healthcare; currently, there is no standardization for access to end-of-life care. There is growing research support for prison-based end-of-life care programs that incorporate inmate peer caregivers as a way to meet the needs of the elderly and dying who are incarcerated.

AIM

This project aims to (a) describe a prison-based end-of-life program utilizing inmate peer caregivers, (b) identify inmate-caregiver motivations for participation, and (c) analyze the role of building trust and meaningful relationships within the correctional end-of-life care setting.

DESIGN

A total of 22 semi-structured interviews were conducted with inmate-caregivers. Data were analyzed using Consensual Qualitative Research methodology.

SETTING/PARTICIPANTS

All inmate-caregivers currently participating in the end-of-life peer care program at Briarcliff Correctional Facility were given the opportunity to participate. All participants were male, over the age of 18, and also incarcerated at Briarcliff Correctional Facility, a maximum security, state-level correctional facility.

RESULTS

In total, five over-arching and distinct domains emerged; this manuscript focuses on the following three: (a) program description, (b) motivation, and (c) connections with others.

CONCLUSION

Findings suggest that inmate-caregivers believe they provide a unique and necessary adaptation to prison-based end-of-life care resulting in multilevel benefits. These additional perceived benefits go beyond a marginalized group gaining access to patient-centered end-of-life care and include potential inmate-caregiver rehabilitation, correctional medical staff feeling supported, and correctional facilities meeting end-of-life care mandates. Additional research is imperative to work toward greater standardization of and access to end-of-life care for the incarcerated.

A consensual qualitative research analysis of the experience of inmate hospice caregivers: Posttraumatic growth while incarcerated

A growing number of correctional facilities train inmates to provide end-of-life care for dying inmates. This study explores the phenomenological perspective of inmate-caregivers participating in an inmate-facilitated hospice program (IFHP) with regard to meaning and purpose in life, attitudes on death and dying, and perceived personal impact of participation. Twenty-two inmate-caregivers were interviewed at a maximum-security state correctional facility in the United States. The interviews were transcribed verbatim and analyzed using the Consensual Qualitative Research Methodology. Results suggest that participating in an IFHP may facilitate personal growth and transformation that mirrors the tenets of posttraumatic growth.

Hospice utilization and end-of-life care in metastatic breast cancer patients at a comprehensive cancer center

BACKGROUND

Metastatic breast cancer patients have many options for therapy and may be at risk for late or absent hospice referrals, which make meaningful improvements in symptoms and quality of life difficult to achieve.

OBJECTIVE

We aimed to examine hospice utilization, status of patients on admission, and quality of care of patients treated for metastatic breast cancer from 1999 to 2010 at a National Cancer Institute (NCI)-designated comprehensive cancer center located in Western New York.

METHODS

We conducted a retrospective database review that identified 182 patients with deaths resulting from breast cancer who were eligible for services through a local not-for-profit hospice. Patients with metastatic breast cancer were matched to the hospice database for information on hospice utilization and quality measures. Date of last chemotherapy, medication use, documentation of advance directive and palliative care discussions, and place of death were collected through chart abstraction.

RESULTS

One-third (33%) of metastatic breast cancer patients treated at the cancer institute during the study period died without a hospice referral. Only 7% of patients who died without a hospice referral had a documented discussion of palliative care as an option by the oncology team (p < 0.001). Those patients referred to hospice were significantly more likely to have an advance directive and to die at home. Patients with a longer duration of metastatic cancer were at risk for late referral.

CONCLUSIONS

Efforts to enhance end-of-life (EOL) discussions and earlier referral to palliative care and hospice for patients with metastatic breast cancer are critical to improved patient care.

Cost savings and enhanced hospice enrollment with a home-based palliative care program implemented as a hospice-private payer partnership

BACKGROUND

In the United States, 5% of the population is responsible for nearly half of all health care expenditures, with a large concentration of spending driven by individuals with expensive chronic conditions in their last year of life. Outpatient palliative care under the Medicare Hospice Benefit excludes a large proportion of the chronically ill and there is widespread recognition that innovative strategies must be developed to meet the needs of the seriously ill while reducing costs.

OBJECTIVE

This study aimed to evaluate the impact of a home-based palliative care program, implemented through a hospice-private payer partnership, on health care costs and utilization.

METHODS

This was a prospective, observational database study where insurance enrollment and claims data were analyzed. The study population consisted of Home Connections (HC) program patients enrolled between January 1, 2010 and December 31, 2012 who subsequently expired (n=149) and who were also Independent Health members. A control group (n=537) was derived using propensity-score matching. The primary outcome variable was overall costs within the last year of life. Costs were also examined at six months, three months, one month, and two weeks. Inpatient, outpatient, ancillary, professional, and pharmacy costs were compared between the two groups. Medical service utilization and hospice enrollment and length of stay were also evaluated.

RESULTS

Cost savings were apparent in the last three months of life—$6,804 per member per month (PMPM) cost for palliative care participants versus $10,712 for usual care. During the last two weeks of life, total allowed PMPM was $6,674 versus $13,846 for usual care. Enhanced hospice entry (70% versus 25%) and longer length of stay in hospice (median 34 versus 9 days) were observed.

CONCLUSIONS

Palliative care programs partnered with community hospice providers may achieve cost savings while helping provide care across the continuum.

Clinical impact of a home-based palliative care program: a hospice-private payer partnership

CONTEXT

Outpatient programs have been traditionally offered in the U.S. under programs such as the Medicare Hospice Benefit. Recommendations now emphasize a blended model in which palliative care is offered concurrently with curative approaches at the onset of serious or life-limiting disease. The efficacy of nonhospice outpatient palliative care programs is not well understood.

OBJECTIVES

The aim of the study was to evaluate the clinical impact of a home-based palliative care program, Home Connections, implemented as a partnership between a not-for-profit hospice and two private insurers.

METHODS

This was a prospective, observational, database study of 499 Home Connections participants enrolled between July 1, 2008, and May 31, 2013. Measured outcomes were advance directive completion, site of death, symptom severity over time, program satisfaction, and hospice referral and average length of stay.

RESULTS

Seventy-one percent of participants completed actionable advance directives after enrollment, and the site of death was home for 47% of those who died during or after participation in the program. Six of eight symptom domains (anxiety, appetite, dyspnea, well-being, depression, and nausea) showed improvement. Patients, caregivers, and physicians gave high program satisfaction scores (93%-96%). Home Connections participants who subsequently enrolled in hospice care had a longer average length of stay of 77.9 days compared with all other hospice referrals (average length of stay 56.5 days).

CONCLUSION

A home-based palliative care program was developed between two local commercial payers and a not-for-profit hospice. Not only did this program improve symptom management, advance directive completion, and satisfaction, but it also facilitated the transition of patients into hospice care, when appropriate.

End-of-life dreams and visions: a longitudinal study of hospice patients' experiences

BACKGROUND

End-of-life dreams and visions (ELDVs) have been well documented throughout history and across cultures. The impact of pre-death experiences on dying individuals and their loved ones can be profoundly meaningful.

OBJECTIVE

Our aim was to quantify the frequency of dreams/visions experienced by patients nearing the end of life, examine the content and subjective significance of the dreams/visions, and explore the relationship of these factors to time/proximity to death.

METHODS

This mixed-methods study surveyed patients in a hospice inpatient unit using a semi-structured interview. Sixty-six patients admitted to a hospice inpatient unit between January 2011 and July 2012 provided informed consent and participated in the study. The semi-structured interviews contained closed and open-ended questions regarding the content, frequency, and comfort/distress of dreams/visions.

RESULTS

Fifty-nine participants comprised the final sample. Most participants reported experiencing at least one dream/vision. Almost half of the dreams/visions occurred while asleep, and nearly all patients indicated that they felt real. The most common dreams/visions included deceased friends/relatives and living friends/relatives. Dreams/visions featuring the deceased (friends, relatives, and animals/pets) were significantly more comforting than those of the living, living and deceased combined, and other people and experiences. As participants approached death, comforting dreams/visions of the deceased became more prevalent.

CONCLUSIONS

ELDVs are commonly experienced phenomena during the dying process, characterized by a consistent sense of realism and marked emotional significance. These dreams/visions may be a profound source of potential meaning and comfort for the dying, and therefore warrant clinical attention and further research.

The Impact of Dreams of the Deceased on Bereavement

Many recently bereaved persons experience vivid and deeply meaningful dreams featuring the presence of the deceased that may reflect and impact the process of mourning. The present study surveyed 278 bereaved persons regarding their own perspective of the relationship between dreams and the mourning process. Fifty eight percent of respondents reported dreams of their deceased loved ones, with varying levels of frequency. Most participants reported that their dreams were either pleasant or both pleasant and disturbing, and few reported purely disturbing dreams. Prevalent dream themes included pleasant past memories or experiences, the deceased free of illness, memories of the deceased's illness or time of death, the deceased in the afterlife appearing comfortable and at peace, and the deceased communicating a message. These themes overlap significantly with previous models of bereavement dream content. Sixty percent of participants felt that their dreams impacted their bereavement process. Specific effects of the dreams on bereavement processes included increased acceptance of the loved one's death, comfort, spirituality, sadness, and quality of life, among others. These results support the theory that dreams of the deceased are highly prevalent among and often deeply meaningful for the bereaved. While many counselors are uncomfortable working with dreams in psychotherapy, the present study demonstrates their therapeutic relevance to the bereaved population and emphasizes the importance for grief counselors to increase their awareness, knowledge, and skills with regards to working with dreams.

The Use of Pentobarbital in Cases of Severe Delirium

Delirium is a common syndrome present at the end of life and causes significant distress for patients and families. Sleep disruption is a common precipitating factor for delirium and restoration of sleep may be instrumental in attenuating symptoms. In this cases series, we present three patients who were unresponsive to escalating doses of standard delirium medications, but whose delirium resolved once improved sleep was achieved using Pentobarbital. In a fourth patient, delirium was successfully treated where neuroleptics were contraindicated. Pentobarbital has been shown to reduce the time to sleep onset, decrease the number of body movements during sleep and spontaneous awakenings and increase the total sleep time. Pentobarbital may provide an additional treatment option for patients whose delirium is refractory to standard management approaches.

Effects of methylphenidate on fatigue and depression: a randomized, double-blind, placebo-controlled trial

CONTEXT

Fatigue is highly prevalent in populations with advanced illness and is often associated with depressed mood. The role of psychostimulant therapy in the treatment of these conditions remains ill defined.

OBJECTIVES

To evaluate the response of fatigue and depression in patients with advanced illness to titrated doses of methylphenidate (MP) as compared with placebo.

METHODS

In a randomized, double-blind, placebo-controlled trial, 30 hospice patients, both inpatients and outpatients, who had fatigue scores of at least four on a scale of zero to 10 (0=no fatigue and 10=worst fatigue), were randomly assigned to receive either 5mg of MP at 8 am and 1 pm or placebo. Doses of MP were titrated every three days according to response and adverse effects. Home care patients were monitored daily by telephone and visited by a research nurse on Study Days 0 (baseline), 3, 7, and 14. Fatigue was assessed using the Piper Fatigue Scale as the primary outcome measure and validated by the Visual Analogue Scale for Fatigue and the Edmonton Symptom Assessment Scale (ESAS) fatigue score. Subjects in inpatient facilities were interviewed or assessed by staff on an identical schedule. Depressive symptoms were assessed by the Beck Depression Inventory-II, Center for Epidemiologic Studies Depression Scale, and the ESAS depression score. Primary statistical analysis was conducted using repeated-measures multivariate analysis of the variance.

RESULTS

Both MP- and placebo-treated groups had similar measures of fatigue at baseline. Patients taking MP were found to have significantly lower fatigue scores (Piper Fatigue Scale, Visual Analogue Scale for Fatigue, and ESAS) at Day 14 compared with baseline. The improvement in fatigue with MP treatment was dose-dependent; the mean average effective dose was 10mg on Day 3 and 20mg on Day 14 (dose range of 10-40 mg). Placebo-treated individuals showed no significant improvement in fatigue. For patients with clinically significant depression on Day 0, treatment with MP was associated with a significant reduction in all test indices for depressed mood. For the placebo group, the changes in measures of depression were less than observed in the treatment group but were inconsistent between assessment tools. No significant toxicities were observed.

CONCLUSION

MP reduced symptoms of fatigue and depression when compared with placebo. The effect of MP on fatigue was dose-dependent and sustained over the duration of the study.

Profound apoptosis-mediated regional myocyte loss and compensatory hypertrophy in pigs with hibernating myocardium

BACKGROUND

Myocyte apoptosis is seen in ischemic heart disease, but whether it can occur after reversible ischemia or independent of necrosis and replacement fibrosis is unknown.

METHODS AND RESULTS

Pigs were instrumented with a stenosis of the left anterior descending coronary artery to chronically reduce coronary flow reserve over a period of 3 months. At this time, there was viable dysfunctional myocardium having the physiological features of hibernating myocardium. Resting subendocardial perfusion was reduced to 0.65+/-0.08 (mean+/-SEM) mL. min(-1). g(-1) in hibernating myocardium of instrumented pigs compared with 0.98+/-0.14 mL. min(-1). g(-1) in myocardium of sham-operated pigs (P<0.05). There was a critical limitation in subendocardial flow during vasodilation to 0.78+/-0.20 mL. min(-1). g(-1) in instrumented pigs versus 3. 24+/-0.50 mL. min(-1). g(-1) in sham-operated pigs (P<0.001). Histology revealed a regional reduction in myocyte nuclear density to 995+/-100 nuclei/mm(2) in hibernating myocardium from the instrumented group versus 1534+/-65 nuclei/mm(2) in myocardium from the sham-operated group (P<0.05), regional myocyte hypertrophy (myocyte volume per nucleus, 14 183+/-2594 in the instrumented group versus 9130+/-1301 microm(3) in the sham group; P<0.05), and minimal increases in connective tissue (5.8+/-0.9% in the instrumented group versus 3.0+/-0.2% in the sham group, P<0.05). Necrosis was not identified, but apoptosis was increased from 30+/-9 myocytes per 10(6) myocyte nuclei in myocardium from the sham group to 220+/-77 myocytes per 10(6) myocyte nuclei in hibernating myocardium (P<0.05).

CONCLUSIONS

These findings indicate that reversible ischemia in an area of chronically reduced coronary flow reserve induces regional myocyte loss via an apoptotic mechanism. This may contribute to the progression of chronic coronary disease to heart failure and explain the lack of complete functional recovery after revascularization in hibernating myocardium.

Purification of dopamine neurons by flow cytometry

The heterogeneity and preponderence of other cell types present in cultures has greatly impeded our ability to study dopamine neurons. In this report, we describe methods for isolating nearly pure dopamine neurons for study in culture. To do so, the lipid-soluble dye, 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (diI) was injected into the embryonic rat striata where it was taken up by nerve terminals and transported overnight back to the innervating perikarya in the ventral midbrain. Midbrain cells were then dissected, dissociated and separated on the basis of their (rhodamine) fluorescence by flow cytometry. Nearly all cells recovered as fluorescent positive (> 98%) were also immunoreactive for the dopamine specific enzyme tyrosine hydroxylase (80%-96%). Little contamination by other cells types was observed after labeling for specific neuronal and glial markers. Purified dopamine neurons continued to thrive and elaborate neuronal processes for at least 3 days in culture. Using this new model, it may now be possible to directly study the cellular and molecular processes regulating the survival and functioning of developing, injured and transplanted dopamine neurons.

The physiological effects of serotonin are mediated by the 5HT1A receptor in the cat's cerebellar cortex

Serotonin is present in a fine beaded plexus in the cerebellar cortex of several mammalian species. In the cat, serotoninergic afferents arise from neurons located within the lateral, paramedian and peri-olivary reticular nuclei (Kerr and Bishop, J. Comp. Neurol., 304 (1991) 502-515). In addition to serotoninergic afferents, these same nuclei also contain a separate population of neurons that give rise to mossy fibers to the cerebellar cortex. Physiological studies have shown that mossy fibers are excitatory to their target neurons. The intent of the present study was to determine the physiological effects of serotonin in the cat's cerebellum in an in vivo preparation and to identify the receptor(s) that mediate the observed responses. Iontophoretic application of serotonin (5HT) onto Purkinje cells reduces the spontaneous firing rate of all cells tested (n = 12). Serotonin also blocks the excitatory effects elicited by the application of aspartate in 17 of 19 units tested and of glutamate (n = 62) in all cases. In addition, 5HT potentiated the inhibitory action of GABA (n = 12). Iontophoretic application of the 5HT1A agonists, 8-OH-DPAT and ipsapirone, mimic the suppressive action of serotonin in a dose-dependent manner. This response, as well as the 5HT mediated suppression are blocked by the application of spiperone, a 5HT1A antagonist. Compounds selective for the 5HT1C,2 and 3 receptors are physiologically ineffective. The present data are in partial agreement with previous studies in the rat's cerebellar cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Topographical organization in the origin of serotoninergic projections to different regions of the cat cerebellar cortex

The distribution of serotonin immunoreactivity in the cat cerebellum was studied by using the indirect antibody peroxidase-antiperoxidase (PAP) technique. Furthermore, the origin of these chemically defined afferents was determined by combining the retrograde transport of horseradish peroxidase (HRP) with the PAP technique. In the cerebellar cortex, serotonin immunoreactivity is present in a plexus of beaded fibers that is confined almost exclusively to the granule and Purkinje cell layers; a few fibers are present in the molecular layer. Serotoninergic axons and varicosities have a dense and uniform distribution throughout all lobules of the cerebellum with the exception of lobule X where the fiber density is sparse. Serotonin cell bodies were not found within the cerebellar cortex. However, following pretreatment with pargyline and L-tryptophan, serotonin positive cell bodies were found in all deep cerebellar nuclei as well as the raphe and reticular nuclei in the brainstem. The present study demonstrates that the serotoninergic projection to the cat's cerebellum has some degree of topographical organization. Serotoninergic fibers in the anterior vermis (lobules I-V) were shown to arise from neurons located within the paramedian reticular nucleus, the lateral reticular nucleus, and the lateral tegmental field. Injections of HRP into either the posterior vermis (lobule VI-IX) or the paramedian lobule, labeled serotoninergic neurons exclusively in the lateral reticular nucleus. Lobus simplex, crus I and crus II (the hemisphere) receive a serotoninergic input from cells located in the lateral tegmental field, the peri-olivary reticular formation and the paramedian reticular nucleus. In no cases were neurons in the raphe double-labeled, although there were cells positive for HRP or serotonin alone. The data indicate that there is a topographical organization in the serotoninergic projection from the caudal brainstem to specific regions of the cat's cerebellar cortex. In addition to climbing and mossy fibers, this projection represents a third major source of cerebellar afferents based on its dense and widespread distribution as well as its morphological and chemical characteristics.

Anthralin-derived transients--II. Formation of the radical by spontaneous fragmentation of both singlet and triplet states of the 10,10'-dehydrodimer: radical pair multiplicity effects

The singlet and triplet states of the anthralin (1,8-dihydroxy-9-anthrone) dehydrodimer have been produced selectively in benzene via pulsed laser excitation and pulse radiolysis respectively. The lifetime of S1 is less than or equal to 30 ps, that of T1 short but unspecified. Both states fragment spontaneously to yield a pair of anthralin radicals. The singlet radical pair predominantly undergoes geminate recombination within the solvent cage. In contrast, the corresponding triplet radical pair undergoes essentially exclusive cage escape to give the anthralin free radical (lambda max 370, 490 and 720 nm) which recombines under normal diffusive conditions. Both recombination processes lead, at least in part, to one or more species which have been assigned as tautomeric forms of the original dimer. The anthralin free radical in benzene is insensitive to the vitamin E model 6-hydroxy-2,2,5,7,8-pentamethylchroman and reacts only slowly with oxygen.

Anthralin-derived transients--I. The triplet state and the products of its reaction with oxygen in benzene

Direct laser excitation in benzene of 1,8-dihydroxy-9-anthrone (anthralin) does not lead to transient species with lifetimes in the nanosecond time regime or longer. The triplet state has been produced in benzene by pulse radiolysis and characterised in terms of its absorption spectrum (lambda max 560 nm), natural lifetime (11 microseconds), self-quenching properties (kmicrosecond = 2.6 x 10(7) l mol-1 s-1) and triplet energy (234 kJ mol-1). There is no tendency in the non-polar medium for production of either the triplet or ground state in a tautomeric form. The observed triplet state reacts with oxygen with a typical rate constant, 2.2 x 10(9) l mol-1 s-1. The products of this reaction are singlet oxygen (approximately 64%) and the anthralin radical (approximately 14%).