Fragile X syndrome arises from blocked expression of the fragile X mental retardation protein (FMRP). Golgi-impregnated mature cerebral cortex from fragile X patients exhibits long, thin, tortuous postsynaptic spines resembling spines observed during normal early neocortical development. Here we describe dendritic spines in Golgi-impregnated cerebral cortex of transgenic fragile X gene (Fmr1) knockout mice that lack expression of the protein. Dendritic spines on apical dendrites of layer V pyramidal cells in occipital cortex of fragile X knockout mice were longer than those in wild-type mice and were often thin and tortuous, paralleling the human syndrome and suggesting that FMRP expression is required for normal spine morphological development. Moreover, spine density along the apical dendrite was greater in the knockout mice, which may ref lect impaired developmental organizational processes of synapse stabilization and elimination or pruning.Fragile X syndrome is the most common inherited form of human mental retardation after Down Syndrome. It is an X-linked genetic trait with an incidence of 1͞2,000 in males (1-3). Phenotypic abnormalities include moderate to severe mental retardation, autistic behavior, macroorchidism, and facial abnormalities (1). The FMR1 gene contains a trinucleotide repeat [(CGG) n ] in the 5Ј untranslated region that is expanded (Ն200 repeats) in fragile X patients (2, 4, 5), resulting in hypermethylation of the FMR1 promoter region and absence of the encoded fragile X mental retardation protein (FMRP). Studies prior to the characterization of fragile X syndrome associated immature dendritic spine morphology (long and thin) with some forms of mental retardation (6-8). Similarly, fragile X cerebral cortical autopsy material exhibits thin, elongated spines and small synaptic contacts (9, 10).Recently, transgenic Fmr1 mice were produced in which the Fmr1 gene was disrupted in embryonic stem cells using a targeting vector to exon 5 and homologous recombination (11). The resultant homozygous knockout mice express no FMRP. Phenotypically, these mice exhibit increased testicular size and mildly impaired performance on the Morris water maze (11), paralleling human symptoms. To explore further parallels to the human syndrome, we examined the effect of the Fmr1 knockout on dendritic spines in the visual cortex using the Golgi-Cox impregnation technique. MATERIALS AND METHODSMale mutant (n ϭ 4) and wild-type FVB strain (n ϭ 4) adult (16-week-old) mice were prepared for Golgi-Cox impregnation. Mice were anesthetized with sodium pentobarbital (85 mg͞kg) and perfused transcardially with 60 ml of 0.9% NaCl (pH 7.3). Brains were removed and were cut sagittally along the midline. Tissue blocks were then immersed in 100 ml of Golgi-Cox solution (1% potassium dichromate͞1% mercuric chloride͞0.8% potassium chromate in distilled water) for 18 days. Tissue blocks were then immersed in 30% sucrose in 0.9% saline for 2 days and subsequently sectioned (200 m) using a vibratome. Sections were mounted o...

Fragile-X syndrome is a common form of mental retardation resulting from the inability to produce the fragile-X mental retardation protein. Qualitative examination of human brain autopsy material has shown that fragile-X patients exhibit abnormal dendritic spine lengths and shapes on parieto-occipital neocortical pyramidal cells. Similar quantitative results have been obtained in fragile-X knockout mice, that have been engineered to lack the fragile-X mental retardation protein. Dendritic spines on layer V pyramidal cells of human temporal and visual cortices stained using the Golgi-Kopsch method were investigated. Quantitative analysis of dendritic spine length, morphology, and number was carried out on patients with fragile-X syndrome and normal age-matched controls. Fragile-X patients exhibited significantly more long dendritic spines and fewer short dendritic spines than did control subjects in both temporal and visual cortical areas. Similarly, fragile-X patients exhibited significantly more dendritic spines with an immature morphology and fewer with a more mature type morphology in both cortical areas. In addition, fragile-X patients had a higher density of dendritic spines than did controls on distal segments of apical and basilar dendrites in both cortical areas. Long dendritic spines with immature morphologies and elevated spine numbers are characteristic of early development or a lack of sensory experience. The fact that these characteristics are found in fragile-X patients throughout multiple cortical areas may suggest a global failure of normal dendritic spine maturation and or pruning during development that persists throughout adulthood.

Local translation of proteins in distal dendrites is thought to support synaptic structural plasticity. We have previously shown that metabotropic glutamate receptor (mGluR1) stimulation initiates a phosphorylation cascade, triggering rapid association of some mRNAs with translation machinery near synapses, and leading to protein synthesis. To determine the identity of these mRNAs, a cDNA library produced from distal nerve processes was used to screen synaptic polyribosome-associated mRNA. We identified mRNA for the fragile X mental retardation protein (FMRP) in these processes by use of synaptic subcellular fractions, termed synaptoneurosomes. We found that this mRNA associates with translational complexes in synaptoneurosomes within 1-2 min after mGluR1 stimulation of this preparation, and we observed increased expression of FMRP after mGluR1 stimulation. In addition, we found that FMRP is associated with polyribosomal complexes in these fractions. In vivo, we observed FMRP immunoreactivity in spines, dendrites, and somata of the developing rat brain, but not in nuclei or axons. We suggest that rapid production of FMRP near synapses in response to activation may be important for normal maturation of synaptic connections.Changes in synaptic connectivity are likely to be a key mechanism by which nervous system organization is permanently changed by experience. Local translation of some proteins in dendrites is increasingly considered to be important for changes in synaptic structure and receptor composition. Certain mRNAs are known to be targeted to dendrites (1, 2), and polyribosomal aggregates are observed in or near dendritic spines, more frequently at newly forming synapses (3-5). Dendrites have been shown to be equipped with components necessary for protein synthesis (6), and synthesis of proteins has been demonstrated directly in synaptoneurosomes (7,8) and in preparations of dendrites isolated from hippocampal neurons in culture (9). Local translation of transfected reporter-tagged mRNA has been demonstrated in transected dendrites (10).Protein translation induced by metabotropic receptor stimulation has previously been proposed to play a role in longterm potentiation (LTP), a model for synaptic plasticity (1,11,12). LTP induction also alters levels of specific mRNAs in tissue slices (13), and isotope-tagged leucine is taken up in dendritic regions of hippocampal slices in response to stimulation (14). We have demonstrated that phosphoinositidelinked metabotropic glutamate receptors (mGluR1), known to trigger a phosphorylation cascade, cause certain mRNAs to associate rapidly with protein translation complexes in synaptoneurosomes (15); this process is modulated by ionotropic receptors (16). Furthermore, we have shown that depolarization by 40 mM K ϩ or stimulation by phosphoinositide receptorspecific mGluR agonists increases [ 35 S]methionine incorporation into trichloroacetic acid-precipitable polypeptides (15, 17), indicating that de novo protein synthesis at the synapse occurs as a result of t...

Fragile-X syndrome is the most common single-gene inherited form of mental retardation. Morphological studies suggest a possible failure of the synapse maturation process. Cerebral cortical spine morphology in fragile-X syndrome and in a knockout mouse model of it appears immature, with long, thin spines much more common than the stubby and mushroom-shaped spines more characteristic of normal development. In human fragile-X syndrome there is also a higher density of spines along dendrites, suggesting a possible failure of synapse elimination. While variously misshapen spines are characteristic of a number of mental retardation syndromes, the overabundance of spines seen in fragile-X syndrome is unusual. Taken with evidence of neurotransmitter activation of the synthesis of the fragile-X protein (FMRP) at synapses in vitro and evidence for behaviorally induced FMRP expression in vivo, and with evidence compatible with a role for FMRP in regulating the synthesis of other proteins, it is possible that FMRP serves as an 'immediate early protein' at the synapse that orchestrates aspects of synaptic development and plasticity.

There is little agreement about what constitutes good death or successful dying. The authors conducted a literature search for published, English-language, peer-reviewed reports of qualitative and quantitative studies that provided a definition of a good death. Stakeholders in these articles included patients, prebereaved and bereaved family members, and healthcare providers (HCPs). Definitions found were categorized into core themes and subthemes, and the frequency of each theme was determined by stakeholder (patients, family, HCPs) perspectives. Thirty-six studies met eligibility criteria, with 50% of patient perspective articles including individuals over age 60 years. We identified 11 core themes of good death: preferences for a specific dying process, pain-free status, religiosity/spiritualty, emotional well-being, life completion, treatment preferences, dignity, family, quality of life, relationship with HCP, and other. The top three themes across all stakeholder groups were preferences for dying process (94% of reports), pain-free status (81%), and emotional well-being (64%). However, some discrepancies among the respondent groups were noted in the core themes: Family perspectives included life completion (80%), quality of life (70%), dignity (70%), and presence of family (70%) more frequently than did patient perspectives regarding those items (35%–55% each). In contrast, religiosity/spirituality was reported somewhat more often in patient perspectives (65%) than in family perspectives (50%). Taking into account the limitations of the literature, further research is needed on the impact of divergent perspectives on end-of-life care. Dialogues among the stakeholders for each individual must occur to ensure a good death from the most critical viewpoint—the patient’s.

Fragile-X syndrome is a common form of mental retardation resulting from the inability to produce the fragile-X mental retardation protein. The specific function of this protein is unknown; however, it has been proposed to play a role in developmental synaptic plasticity. Examination of human brain autopsy material has shown that fragile-X patients exhibit abnormalities in dendritic spine structure and number, suggesting a failure of normal developmental dendritic spine maturation and pruning in this syndrome. Similar results using a knockout mouse model have previously been described; however, it was noted in retrospect that the mice used in that study may have carried a mutation for retinal degeneration, which may have affected cell morphology in the visual cortex of those animals. In this study, dendritic spines on layer V pyramidal cells of visual cortices, taken from fragile-X knockout and wild-type control mice without the retinal degeneration mutation and stained using the Golgi-Cox method, were investigated for comparison with the human condition. Quantitative analyses of the lengths, morphologies, and numbers of dendritic spines, as well as amount of dendritic arbor and dendritic branching complexity, were conducted. The fragile-X mice exhibited significantly more long dendritic spines and significantly fewer short dendritic spines than control mice. Similarly, fragile-X mice exhibited significantly more dendritic spines with an immature-like morphology and significantly fewer with a more mature type morphology. However, unlike the human condition, fragile-X mice did not exhibit statistically significant dendritic spine density differences from controls. Fragile-X mice also did not demonstrate any significant differences from controls in dendritic tree complexity or dendritic arbor. Long dendritic spines with immature morphologies are characteristic of early development or a lack of sensory experience. These results are similar to those found in the human condition and further support a role for the fragile-X mental retardation protein specifically in normal dendritic spine developmental processes. They also support the validity of these mice as a model of fragile-X syndrome.

Protein synthesis occurs in neuronal dendrites, often near synapses. Polyribosomal aggregates often appear in dendritic spines, particularly during development. Polyribosomal aggregates in spines increase during experience-dependent synaptogenesis, e.g., in rats in a complex environment. Some protein synthesis appears to be regulated directly by synaptic activity. We use ''synaptoneurosomes,'' a preparation highly enriched in pinched-off, resealed presynaptic processes attached to resealed postsynaptic processes that retain normal functions of neurotransmitter release, receptor activation, and various postsynaptic responses including signaling pathways and protein synthesis. We have found that, when synaptoneurosomes are stimulated with glutamate or group I metabotropic glutamate receptor agonists such as dihydroxyphenylglycine, mRNA is rapidly taken up into polyribosomal aggregates, and labeled methionine is incorporated into protein. One of the proteins synthesized is FMRP, the protein that is reduced or absent in fragile X mental retardation syndrome. FMRP has three RNA-binding domains and reportedly binds to a significant number of mRNAs. We have found that dihydroxyphenylglycine-activated protein synthesis in synaptoneurosomes is dramatically reduced in a knockout mouse model of fragile X syndrome, which cannot produce full-length FMRP, suggesting that FMRP is involved in or required for this process. Studies of autopsy samples from patients with fragile X syndrome have indicated that dendritic spines may fail to assume a normal mature size and shape and that there are more spines per unit dendrite length in the patient samples. Similar findings on spine size and shape have come from studies of the knockout mouse. Study of the development of the somatosensory cortical region containing the barrel-like cell arrangements that process whisker information suggests that normal dendritic regression is impaired in the knockout mouse. This finding suggests that FMRP may be required for the normal processes of maturation and elimination to occur in cerebral cortical development.

BackgroundAs a significant proportion of patients receiving palliative care suffer from states of anxiety, depression, delirium, or other mental symptoms, psychiatry and palliative care already collaborate closely in the palliative care of medical conditions. Despite this well-established involvement of psychiatrists in palliative care, psychiatry does not currently explicitly provide palliative care for patients with mental illness outside the context of terminal medical illness.DiscussionBased on the WHO definition of palliative care, a, a working definition of palliative psychiatry is proposed. Palliative psychiatry focuses on mental health rather than medical/physical issues. We propose that the beneficiaries of palliative psychiatry are patients with severe persistent mental illness, who are at risk of therapeutic neglect and/or overly aggressive care within current paradigms. These include long-term residential care patients with severe chronic schizophrenia and insufficient quality of life, those with therapy-refractory depressions and repeated suicide attempts, and those with severe long-standing therapy-refractory anorexia nervosa. An explicitly palliative approach within psychiatry has the potential to improve quality of care, person-centredness, outcomes, and autonomy for patients with severe persistent mental illness.ConclusionsThe first step towards a palliative psychiatry is to acknowledge those palliative approaches that already exist implicitly in psychiatry. Basic skills for a palliative psychiatry include communication of diagnosis and prognosis, symptom assessment and management, support for advance (mental health) care planning, assessment of caregiver needs, and referral to specialized services. Some of these may already be considered core skills of psychiatrists, but for a truly palliative approach they should be exercised guided by an awareness of the limited functional prognosis and lifespan of patients with severe persistent mental illness.