Flow electrochemistry: a safe tool for fluorine chemistry.

The heightened activity of compounds containing fluorine, especially in the field of pharmaceuticals, provides major impetus for the development of new fluorination procedures. A scalable, versatile, and safe electrochemical fluorination protocol is conferred. The strategy proceeds through a transient (difluoroiodo)arene, generated by anodic oxidation of an iodoarene mediator.

Continuous-Flow Electrochemical Generator of Hypervalent Iodine Reagents: Synthetic Applications.

An efficient and reliable electrochemical generator of hypervalent iodine reagents has been developed. In the anodic oxidation of iodoarenes to hypervalent iodine reagents under flow conditions, the use of electricity replaces hazardous and costly chemical oxidants. Unstable hypervalent iodine reagents can be prepared easily and coupled with different substrates to achieve oxidative transformations in high yields.

Menthol activation of corneal cool cells induces TRPM8-mediated lacrimation but not nociceptive responses in rodents.

Purpose: Stimulation to the cornea via noxious chemical and mechanical means evokes tearing, blinking, and pain. In contrast, mild cooling of the ocular surface has been reported to increase lacrimation via activation of corneal cool primary afferent neurons. The purpose of our study was to determine whether menthol induces corneal cool cell activity and lacrimation via the transient receptor potential melastatin-8 (TRPM8) channel without evoking nociceptive responses.

Chronic morphine increases Fos-positive neurons after concurrent cornea and tail stimulation.

Objective: The aim of the present study was to examine the effect of chronic morphine exposure on diffuse noxious inhibitory controls in a large population of neurons throughout the medullary dorsal horn, as assessed using immunocytochemistry for c-Fos protein.

Background: Overuse of medications, including the opioids, to treat migraine headache can lead to progressively more frequent headaches. In addition, chronic daily headache sufferers and chronic opioid users both lack the inhibition of pain produced by noxious stimulation of a distal body region, often referred to as diffuse noxious inhibitory controls.

Time course of substance P expression in dorsal root ganglia following complete spinal nerve transection.

Recent evidence suggests that substance P (SP) is up-regulated in primary sensory neurons following axotomy and that this change occurs in larger neurons that do not usually produce SP. If this is so, then the up-regulation may allow normally neighboring, uninjured, and nonnociceptive dorsal root ganglion (DRG) neurons to become effective in activating pain pathways. By using immunohistochemistry, we performed a unilateral L5 spinal nerve transection on male Wistar rats and measured SP expression in ipsilateral L4 and L5 DRGs and contralateral L5 DRGs at 1-14 days postoperatively (dpo) and in control and sham-operated rats.

Paw withdrawal thresholds and persistent hindlimb flexion in experimental mononeuropathies.

Hypersensitivity of the foot produced by a number of sciatic mononeuropathies was assessed and compared. A new tool was used, the strain-gauge algometer, that delivers a noxious stimulus and gives a direct measurement of the force for paw withdrawal. In addition, we report observations of another alteration of the flexion reflex, persistent hindlimb flexion.

The effects of manually applied intermittent pulsation pressure to rat ventral thorax on lymph transport.

The present study evaluated the effects of tissue massage on a part of the body remote from the region of lymph uptake into the initial lymphatics. Lymph uptake was assessed with a fluorescent probe placed in a potential space of the lower extremity of anesthetized female Sprague-Dawley rats. Tail blood was assayed at intervals over 15 hours for fluorescence.

Properties of peripherally induced persistent hindlimb flexion in rat: involvement of N-methyl-D-aspartate receptors and capsaicin-sensitive afferents.

In the sodium pentobarbital anesthetized rat, percutaneous electrical stimulation (2 mA, 7 ms, 100 Hz, 60 min) across the upper hindlimb produces an ipsilateral hindlimb flexion that persists following spinal transection. Using this preparation, the following were found. (1) Flexion was observed in both the intact and acutely spinalized (T7) rat 10 hours to two weeks following induction, but was negligible at six weeks.

Intrathecally administered N-methyl-D-aspartate increases persistent hindlimb flexion in rat.

Persistent hindlimb flexion was induced in pentobarbital anesthetized rats using a prolonged, electrical stimulus. Intrathecal (i.t.

Behaviors induced by 5-hydroxytryptophan in neonatal, preweaning, postweaning, and adult Sprague-Dawley rats.

The behaviors induced by the 5-hydroxytryptamine (5-HT) precursor 5-hydroxytryptophan (5-HTP) has been called the "5-HT (serotonin) syndrome." These behaviors and others identified in rat pups were observed following administration of 5-HTP (300 mg/kg, SC) on postnatal (PN) days 3, 14, and 28 and in adult rats. Certain 5-HT syndrome behaviors and other uniquely neonatal behaviors were present in PN3 pups treated with vehicle.

Inhibition of chronic hindlimb flexion in rat: evidence for mediation by 5-hydroxytryptamine.

Prolonged high-intensity stimulation of the rat hindlimb produces a persistent unilateral flexion. 5-Hydroxytryptamine (5-HT) has been implicated in the modulation of spinal cord mechanisms. Electrical stimulation across the upper hindlimb was used to induce a persistent hindlimb flexion.

Direction-selective single units in the nucleus lentiformis mesencephali of the pigeon (Columba livia).

The receptive field properties of single units within the nucleus lentiformis mesencephali (LM) of the pigeon were studied using electrophysiological methods. Previous studies have suggested that the avian LM may be homologous to the nucleus of the optic tract (NOT) in mammals. Single units in the pigeon LM are similar to mammalian NOT units in that they are direction-selective, mostly for horizontal directions, velocity-selective, have large visual receptive fields and respond preferentially to large stimuli with many visual contrasts.

Semicircular canal orientation in the adult resting rabbit.

Photographs of rabbits in the alert resting position were used to record head position. Semicircular canals were surgically exposed and points measured along each canal were used to compute the best-fit plane using a least-squares method. Computations of mean best-fit planes showed that the horizontal canals were not carried horizontally in the rabbit.

Inversion of direction-selectivity to anterior fields in neurons of nucleus of the optic tract in rabbits with ocular albinism.

Extracellular recordings were made of 46 well-isolated single units in the nucleus of the optic tract (NOT) from 27 rabbits which were paralyzed but unanesthetized. Rabbits were selected from 3 varieties with ocular albinism. These units showed short latencies (mean = 2.

Post-rotary nystagmus and optokinetic after-nystagmus in the rabbit linear rather than exponential decay.

The decay of the slow phase velocity of post-rotatory (PRN) and optokinetic (OKAN) after-nystagmus as a function of time was measured in Dutch rabbits after stimulation with velocity steps of 30, 60, and 150 degrees/s. The decays fitted linear functions very well, but only poorly exponential ones. Typical decay rates were 2-5 degrees/s2, with apparent time constants (defined by decay to 37% of initial velocity) in the order of 10-20 s.

Optokinetic eye movements in albino rabbits: inversion in anterior visual field.

When visual contrasts are restricted to the anterior sector (90 degrees to 180 degrees) of the albino rabbit's visual field, eye position is dramatically unstable, and when such contrasts are moved, horizontal optokinetic eye movements are inverted: the direction of pursuit is opposite to that of the stimulus. In the posterior visual field stability and optokinetic reactions are normal, as in all parts of the pigmented rabbit's visual field. This phenomenon may be one more of the complex of visual system defects linked to albinism.