Serotonin is a native neuromodulator of synaptic transmission at glutamatergic neuromuscular junctions of crayfish limb muscles. During times of stress, serotonin binds to presynaptic receptors, which activate adenylyl cyclase to elevate presynaptic levels of cAMP. cAMP binds to two presynaptic target proteins, hyperpolarization and cyclic nucleotide-activated (HCN) ion channels and an exchange protein activated by cAMP (Epac), and activation of these effectors results in enhancement of transmitter release to action potentials.
View Article and Find Full Text PDFThe induction of mossy fiber-CA3 long-term potentiation (LTP) and depression (LTD) has been variously described as being dependent on either pre- or postsynaptic factors. Some of the postsynaptic factors for LTP induction include ephrin-B receptor tyrosine kinases and a rise in postsynaptic Ca2+ ([Ca2+]i). Ca2+ is also believed to be involved in the induction of the various forms of LTD at this synapse.
View Article and Find Full Text PDFObjective: This longitudinal study uses a three-generation database involving measures of grandparental and parental alcohol use disorder (AUD), marital aggression and aggression to offspring to predict early and later childhood aggression of third generation offspring. Given the importance of aggressive, undercontrolled behavior in the etiology of alcoholism, the purpose of this study was to construct a statistical model of intergenerational aggression and alcoholism among family members.
Method: Participants were a population-based sample of 186 young sons of alcoholics and both biological parents and 120 nonsubstance abusing families and their age-matched sons drawn from the same neighborhoods.
The spontaneous fusion of vesicles at nerve terminals produces random miniature postsynaptic potentials (quantal responses) that are thought to have little functional significance. In this issue of Neuron, Sharma and Vijayaraghavan provide evidence that exogenous signals can accelerate and synchronize the occurrence of quanta strongly enough to activate postsynaptic neurons in what may be a new way to transfer information across synapses.
View Article and Find Full Text PDFIn this research, we examined the convergent validity, internal structure, and interparent agreement of the Child Behavior Checklist (CBCL; Achenbach, 1991a) using data from a community sample of 317 high-risk families. The sample consisted of 218 families with alcoholism (biological mother, father, and son) and 99 matched comparison families without alcoholism; all families were intact and included a 3- to 5-year-old son at first contact. Evidence was found for the convergent validity of the CBCL.
View Article and Find Full Text PDFBackground: LysoTracker Red (LT) is a paraformaldehyde fixable probe that concentrates into acidic compartments of cells and tissues. After cell death, a high level of lysosomal activity (acidic enzyme) is expressed in tissues resulting from phagocytosis of apoptotic bodies by neighboring cells. LT was shown previously to be an indicator of cell death in a manner similar to other standard assays (Annexin, terminal dUTP nick end labeling, Nile blue sulfate, neutral red, and acridine orange).
View Article and Find Full Text PDFThis study examined trajectories of disruptive behavior problems from preschool to early adolescence in 302 boys from a community-recruited sample of high-risk families. Growth modeling showed that paternal alcoholism was associated with elevated levels of sons' disruptive behavior problems. Family conflict predicted more disruptive behaviors at school entry and a slower rate of decline in such problems.
View Article and Find Full Text PDFBrief exposure to some pesticides, applied during a sensitive window for the neural regulation of ovulation, will block the preovulatory surge of LH and, thus, delay ovulation. Previously, we have shown that a single i.p.
View Article and Find Full Text PDFJ Pastoral Care Counsel
March 2003
The authors observe that Clinical Pastoral Education (CPE) developed out of a Protestant setting. Much of its thinking and writing therefore is heavily laden with Christian orientation and terminology. Sharing a general theological framework, most Christians read these words and think of the same- or similar-ideas.
View Article and Find Full Text PDFProgrammed cell death or apoptosis occurs in many tissues during normal development and in the normal homeostasis of adult tissues. Apoptosis also plays a significant role in abnormal development and disease. Increased interest in apoptosis and cell death in general has resulted in the development of new techniques and the revival of old ones.
View Article and Find Full Text PDFAcute exposure of mouse embryos to ethanol during stages of hindbrain segmentation results in excessive cell death in specific cell populations. This study details the ethanol-induced cell loss and defines the subsequent effects of this early insult on rhombomere and cranial nerve development. Ethanol at a teratogenic dosage (2.
View Article and Find Full Text PDFGlutathione (GSH) is thought to play critical roles in oocyte function including spindle maintenance and provision of reducing power needed to initiate sperm chromatin decondensation. Previous observations that GSH concentrations are higher in mature than immature oocytes and decline after fertilization, suggest that GSH synthesis may be associated with cell cycle events. To explore this possibility, we measured the concentrations of GSH in Golden Hamster oocytes and zygotes at specific stages of oocyte maturation and at intervals during the first complete embryonic cell cycle.
View Article and Find Full Text PDFFour subjects living with profoundly debilitating and life-threatening illnesses reflect on how psychotherapy has contributed to their ability to cope and survive. With frankness and eloquence they address issues related to cancer, heart disease, fibromyalgia, and AIDS.
View Article and Find Full Text PDFCentral serotonin dysfunction appears to be related to a subtype of alcoholism with antisocial impulsive features (type II; antisocial alcoholism). The serotonergic deficit may be associated with greater impulsivity, which in turn facilitates both alcohol dependence and antisocial behavior. The present study tested association of antisocial impulsive alcoholism with candidate genes related to serotonergic neurotransmission, using families.
View Article and Find Full Text PDFA functional polymorphism in the regulatory region of the serotonin transporter gene (5-HTTLPR) is considered to be a plausible candidate gene for anxiety-related personality traits and for alcoholism. Empirical support for the association between 5-HTTLPR and psychological traits has been somewhat inconsistent; however, observations of the functional dominance of the low-activity s-allele over the l-allele have been more consistent. When studying the influence of particular genes on psychological traits, it seems useful also to assess more biological intermediate traits that may mediate the effects of those genes on the traits of interest.
View Article and Find Full Text PDFPresynaptic I(h) channels become activated during a tetanus through membrane hyperpolarization resulting from Na(+) accumulation and electrogenic Na(+)/K(+) exchange. I(h) activation is obligatory for inducing long-term facilitation (LTF), a long-lasting synaptic strengthening. cAMP-induced synaptic enhancement also requires I(h) activation, and both processes are sensitive to actin depolymerization.
View Article and Find Full Text PDFSynaptic transmission is a dynamic process. Postsynaptic responses wax and wane as presynaptic activity evolves. This prominent characteristic of chemical synaptic transmission is a crucial determinant of the response properties of synapses and, in turn, of the stimulus properties selected by neural networks and of the patterns of activity generated by those networks.
View Article and Find Full Text PDFWe previously established that levels of the sperm membrane protein, SP22, are highly correlated with the fertility of sperm from the cauda epididymidis of rats exposed to both epididymal and testicular toxicants, and that a testis-specific SP22 transcript is expressed in postmeiotic germ cells. In this study, polyclonal and monoclonal antibodies were generated to study the expression of SP22 in the testis and epididymis, and to determine whether SP22 plays a coincidental or causal role in fertility. Polyclonal antiserum was raised in sheep against full-length recombinant rat SP22 (rSP22).
View Article and Find Full Text PDFWe have explored the processes regulating presynaptic calcium concentration ([Ca(2+)](i)) in the generation of post-tetanic potentiation (PTP) at crayfish neuromuscular junctions, using spectrophotometric dyes to measure changes in [Ca(2+)](i) and [Na(+)](i) and effects of inhibitors of Ca(2+)-transport processes. The mitochondrial Na(+)/Ca(2+) exchange inhibitor CGP 37157 was without effect, whereas the reverse mode plasmalemmal Na(+)/Ca(2+) exchange inhibitor KB R7943 reduced PTP and Ca(2+) accumulation caused by increased [Na(+)](i). Exchange inhibitory peptide and C28R2 had opposite effects, consistent with their block of the plasma membrane Ca(2+) ATPase.
View Article and Find Full Text PDFLong-term facilitation at the crayfish opener muscle is elicited by prolonged high frequency stimulation, and arises from an increase in functional active zones, resulting in increased transmitter release. LTF induction depends critically upon presynaptic calcium accumulation and calcineurin (PP2B) activity. The protein synthesis dependence of this synaptic strengthening was investigated.
View Article and Find Full Text PDFBackground: Ethanol-induced cell death has been characterized in very few stages of embryogenesis. This investigation comprehensively maps patterns of both programmed and ethanol-induced cell death in the central nervous system and craniofacial region at 0.5-day intervals from gestational day (GD) 6.
View Article and Find Full Text PDF1. When buccal neuron B2 of Aplysia californica is co-cultured with sensory neurons (SNs), slow peptidergic synapses are formed. When B2 is co-cultured with neurons B3 or B6, fast cholinergic synapses are formed.
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