Venlafaxine extended release (ER) in the treatment of generalised anxiety disorder: twenty-four-week placebo-controlled dose-ranging study.

Background: Generalised anxiety disorder (GAD) has received less study than other anxiety disorders, particularly its long-term treatment.

Aims: To assess the efficacy and safety of venlafaxine extended release (ER) in patients with GAD.

Method: A total of 541 out-patients, 18-86 years old, were recruited to this 24-week, placebo-controlled, double-blind study of three fixed doses (37.

Touch and go: decision-making mechanisms in somatosensation.

A complex sequence of neural events unfolds between sensory receptor activation and motor activity. To understand the underlying decision-making mechanisms linking somatic sensation and action, we ask what components of the neural activity evoked by a stimulus are directly related to psychophysical performance, and how are they related. We find that single-neuron responses in primary and secondary somatosensory cortices account for the observed performance of monkeys in vibrotactile discrimination tasks, and that neuronal and behavioral responses covary in single trials.

Neurofilament expression in cultured rat adenohypophysial cells.

The aim of the present work was to investigate in cultured rat adenohypophysial cells: a) the presence of neurofilaments of 200 kDa (NF-H), b) the effect of thyroid hormone (T(3)) and thyrotropin releasing hormone (TRH) on the expression of NF-H and c) the possible role of NF-H on thyrotropin (TSH) secretion. The presence of NF-H was observed by immunocytochemistry in cultured rat adenohypophysial cells. The exposure to T(3) for 12 h produced a significant increase in NF-H expression; whereas incubation with TRH or T(3)+TRH resulted in no change.

Zaleplon shortens subjective sleep latency and improves subjective sleep quality in elderly patients with insomnia. The Zaleplon Clinical Investigator Study Group.

Insomnia is a frequent complaint in the elderly population. Hypnotic agents, including benzodiazepines, with longer pharmacological half-lives have been associated with side effects, including residual sedation, memory impairment, and discontinuation effects. Zaleplon is a short-acting (elimination half-life of 1 hour), non-benzodiazepine hypnotic that acts on the benzodiazepine type 1 site of the gamma-aminobutyric acid type A (GABA(A)) receptor complex.

Impact of correlated synaptic input on output firing rate and variability in simple neuronal models.

Cortical neurons are typically driven by thousands of synaptic inputs. The arrival of a spike from one input may or may not be correlated with the arrival of other spikes from different inputs. How does this interdependence alter the probability that the postsynaptic neuron will fire? We constructed a simple random walk model in which the membrane potential of a target neuron fluctuates stochastically, driven by excitatory and inhibitory spikes arriving at random times.

Periodicity and firing rate as candidate neural codes for the frequency of vibrotactile stimuli.

The flutter sensation is felt when mechanical vibrations between 5 and 50 Hz are applied to the skin. Neurons with rapidly adapting properties in the somatosensory system of primates are driven very effectively by periodic flutter stimuli; their evoked spike trains typically have a periodic structure with highly regular time differences between spikes. A long-standing conjecture is that, such periodic structure may underlie a subject's capacity to discriminate the frequencies of periodic vibrotactile stimuli and that, in primary somatosensory areas, stimulus frequency is encoded by the regular time intervals between evoked spikes, not by the mean rate at which these are fired.

Efficacy of venlafaxine extended-release capsules in nondepressed outpatients with generalized anxiety disorder: A 6-month randomized controlled trial.

Context: Generalized anxiety disorder (GAD) is a chronic disorder that is associated with debilitating psychic and somatic symptoms. Venlafaxine extended-release (XR) capsules have been shown to be effective in short-term treatment of patients with GAD without major depressive disorder (MDD), but long-term data are needed to establish whether this agent confers persistent benefits.

Objective: To compare the 6-month efficacy and safety of a flexible dosage of venlafaxine XR in outpatients with GAD without associated MDD.

Immunohistochemical study of Syntaxin-1 and SNAP-25 in the pituitaries of mouse, guinea pig and cat.

In the present work we have investigated the presence of the membrane proteins Syntaxin-1 and synaptosomal-associated protein (SNAP-25) by immunohistochemistry in the different parts of the pituitary of mouse, guinea pig and cat. We have demonstrated Syntaxin-1 and SNAP-25 immunoreactivity in the adenohypophysis as well as in the neurohypophysis but not in intermediate lobe. The results suggest that Syntaxin-1 and SNAP-25 are involved in the hormonal secretary process of adenohypophysis as well as neurohypophysis of these animals.

Concentration-dependent effects of nitric oxide on mitochondrial permeability transition and cytochrome c release.

The mitochondrial permeability transition pore (PTP) and associated release of cytochrome c are thought to be important in the apoptotic process. Nitric oxide (NO( small middle dot)) has been reported to inhibit apoptosis by acting on a variety of extra-mitochondrial targets. The relationship between cytochrome c release and PTP opening, and the effects of NO( small middle dot) are not clearly established.

Posterior chamber silicone intraocular lens for the correction of myopia: an experimental study in rabbits.

Purpose: To establish whether ocular lesions arise after implantation of posterior chamber silicone intraocular lenses (IOL) for the correction of high myopia.

Methods: Twenty-three posterior chamber silicone IOL were implanted in 23 eyes of the same number of pigmented rabbits. After different follow-up time (from one week to one year) the eyes were enucleated and processed for histopathological study after determining the protein concentration in the aqueous humor.

[Spontaneous intracranial hypotension].

Introduction And Clinical Case: A 38 year old woman, with no previous history of trauma, presented complaining of interscapular pain followed by pulsating headache clearly related to posture, alleviated on lying down and worse on standing up. Subsequently, she also complained of diplopia. On examination there was paresia of the left sixth cranial nerve.

[A validity study of continuous Doppler].

Introduction: Ultrasound is regularly used for the detection of carotid stenosis which can be treated surgically. This technique includes continuous Doppler, which together with study of blood flow in the orbit is very useful and should be used systematically, not only in certain cases. We present a study of the usefulness of this technique in our Cerebral Vascular Pathology Laboratory.

Do simple cells in primary visual cortex form a tight frame?

Sets of neuronal tuning curves, which describe the responses of neurons as functions of a stimulus, can serve as a basis for approximating other functions of stimulus parameters. In a function-approximating network, synaptic weights determined by a correlation-based Hebbian rule are closely related to the coefficients that result when a function is expanded in an orthogonal basis. Although neuronal tuning curves typically are not orthogonal functions, the relationship between function approximation and correlation-based synaptic weights can be retained if the tuning curves satisfy the conditions of a tight frame.

Sleep latency is shortened during 4 weeks of treatment with zaleplon, a novel nonbenzodiazepine hypnotic. Zaleplon Clinical Study Group.

Background: Zaleplon is a short-acting pyrazolopyrimidine hypnotic with a rapid onset of action. This multicenter study compared the efficacy and safety of 3 doses of zaleplon with those of placebo in outpatients with DSM-III-R insomnia. Zolpidem, 10 mg, was used as an active comparator.

Sensing and deciding in the somatosensory system.

Combined psychophysical and neurophysiological experiments have revealed some of the neural codes associated with perception and processing of tactile information. Recently, intracortical microstimulation was used to demonstrate a causal link between primary cortical activity and perception. Evidence for a subsequent link, between a sensory decision process and its expression as a movement, has been found in motor areas.

Immunohistochemical demonstration of syntaxin and SNAP-25 in chromaffin cells of the frog adrenal gland.

The release of catecholamines from chromaffin cells involves specific proteins such as synaptobrevin present in the secretory vesicles as well as syntaxin and synaptosomal-associated protein of 25 kDa (SNAP-25), both present in the plasma membrane. We have found syntaxin and SNAP-25 in chromaffin cells of the frog adrenal gland by immunohistochemistry. This result suggests that the secretion of catecholamines from chromaffin cells involves these proteins in the frog.

Engineered peptides corresponding to segments of the H3 domain of syntaxin inhibit insulin release both in intact and permeabilized mouse pancreatic beta cells.

Syntaxin is one of the proteins involved in the exocytotic event through sequential binding to specific proteins, including SNAP25 and synaptobrevin. In a previous work in digitonin-permeabilized beta cells, we characterized the functional role of two segments: synA and synB of the H3 domain of syntaxin. As a continuation of these experiments in the present study we have initially outlined a zone of 17 residues as the very effective uncoupling element of the synA segment.

[Familial internal carotid dissection].

Cervicocerebral arterial dissections is responsible for 20% of first strokes in young adults. Several diseases of the connective tissue and wall vessels anomalies are considered predisposing of arterial dissection. Familiar cases have been reported in 5%, according to hereditary primary arteriopathy, such as fibromuscular dysplasia.

Somatosensory discrimination based on cortical microstimulation.

The sensation of flutter is produced when mechanical vibrations in the range of 5-50Hz are applied to the skin. A flutter stimulus activates neurons in the primary somatosensory cortex (S1) that somatotopically map to the site of stimulation. A subset of these neurons-those with quickly adapting properties, associated with Meissner's corpuscles-are strongly entrained by periodic flutter vibrations, firing with a probability that oscillates at the input frequency.

Effects of a toxin from the mucus of the Caribbean sea anemone (Bunodosoma granulifera) on the ionic currents of single ventricular mammalian cardiomyocytes.

The effects were studied of a toxin (Bainh) isolated from the secretion of the Caribbean sea anemone Bunodosoma granulifera on electrical and mechanical activities of rat ventricular muscle. The effects on the ionic currents of single rat and dog ventricular cardiomyocytes were studied using the whole-cell recording patch-clamp technique. In the concentration range from 1 to 10 mg/ml, Bainh increased the force of contraction and induced an increase in action potential duration of ventricular multicellular preparations.

Conversion of sensory signals into motor commands in primary motor cortex.

Movement triggered by sensory stimuli requires that the networks generating the motor commands receive an adequate driving input, which, in general, is a transformed version of the initial sensory signal. We investigated the nature of this transformation in a task in which monkeys categorize the speed of tactile stimuli as either low or high, reaching for one of two pushbuttons to indicate their choice. Extracellular recordings from primary motor cortex revealed two types of neurons selective for the speed categories: ones that fire at higher rates for low versus high speeds, and others that do the opposite.