Episodic vestibular disruption following ablation of the inferior olive in rats: behavioral correlates.

The experiments herein investigate whether the behavioral responses to transient and episodic vestibular disruption and permanent ablation are distinct in the absence of climbing fiber input. Subjects in group 1 received an IP injection of PBS followed by an IP injection of niacinamide. Seven days later these rats received the first of 3 serial transtympanic injections of TTX on the same side with 7 days between each injection.

Ultrastructure and synaptology of the paratrigeminal nucleus in the rat: primary pharyngeal and laryngeal afferent projections.

The paratrigeminal nucleus (PTN) receives primary afferent projections from the aerodigestive tract and orofacial regions and plays a role in the integration of visceral and somatic information. This study describes the fine structure of the rat PTN and the synaptology of primary afferent projections from the pharynx and larynx. Injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) or cholera toxin-HRP (CT-HRP) were made into the wall of the pharynx or larynx to label primary afferent axon terminals.

Episodic blockade of cranial nerve VIII provokes asymmetric changes in lobule X of the rat.

Although debilitating syndromes like Ménière's disease are in part characterized by recurrent or episodic vestibular disturbance the study of episodic vestibular disruption has only recently been possible with the introduction of a new model utilizing tetrodotoxin (TTX). In the present study, serial unilateral transtympanic administration of TTX produced behavioral symptoms indicative of transient vestibular disruption and novel patterns of Fos activity in the brainstem and cerebellum. Following two or three serial injections of TTX and a final survival time of 2 h, Fos immunocytochemistry revealed a distinct pattern of labeling in the brainstem that differed temporally from that observed following a single unilateral TTX injection.

Distribution of Fos labeling in the inferior olive following transient blockade of the VIIIth cranial nerve.

The sodium channel blocker, tetrodotoxin (TTX), is an effective tool for blockade of action potentials in neurons. Unilateral transtympanic administration of 3 mM TTX produced behavioral symptoms paralleling those previously reported following unilateral vestibular ablation. Behavioral symptoms were evident as early as 15 min post-TTX.

Asymmetric Fos labeling in lobule X of the cerebellum following transtympanic tetrodotoxin (TTX) in the rat.

Unilateral transtympanic administration of the sodium channel blocker tetrodotoxin (75 microl of 3 mM TTX in 0.1 M citrate buffer, pH 5.0) produced behavioral symptoms indicative of unilateral vestibular disruption.

Reduction of submissive behavior in rats: a test for antidepressant drug activity.

Randomly paired rats were food deprived overnight and placed in an apparatus compelling them to compete for a food reward. About half of these pairs developed a dominant-submissive relationship measured as a significant difference in time spent on the feeder by each rat. This relationship developed over a 2-week period and remained stable for at least the next 5 weeks.

Tramadol/acetaminophen combination tablets and codeine/acetaminophen combination capsules for the management of chronic pain: a comparative trial.

Background: Opioid/acetaminophen (APAP) combination analgesics are widely prescribed for the relief of moderate pain. Tramadol is a synthetic analgesic that has been shown to be effective both alone and in combination with APAP.

Objective: The purpose of this study was to compare the efficacy and tolerability of tramadol/APAP tablets with codeine/APAP capsules.

Transtympanic tetrodotoxin alters the VOR and Fos labeling in the vestibular complex.

The sodium channel blocker tetrodotoxin (TTX) is an effective tool for blockade of action potentials. Unilateral transtympanic administration of 3 mM TTX produced behavioral symptoms similar to those following unilateral peripheral vestibular ablation. Complete resolution of visible symptoms occurred between 48 and 72 h post-TTX.

The normal distribution and projections of constitutive NADPH-d/NOS neurons in the brainstem vestibular complex of the rat.

The vestibular system is a highly conserved sensory system in vertebrates that is largely responsible for maintenance of one's orientation in space, posture, and balance and for visual fixation of objects during motion. In light of the considerable literature indicating an involvement of nitric oxide (NO) in sensory systems, it is important to determine whether NO is associated with vestibular pathways. To study the relationship of NO to vestibular pathways, we first examined the normal distribution of constitutive NADPH-diaphorase (NADPH-d), a marker for nitric oxide synthase (NOS), in the vestibular complex (VC) and then examined its association with selected vestibular projection neurons.

Possible nosocomial transmission of psittacosis.

Objectives: To investigate a cluster of seven pneumonia cases among persons exposed to a pet-shop worker hospitalized with psittacosis.

Design: Epidemiological study of the outbreak, sero-diagnostic evaluation of exposed persons with pneumonia; and retrospective review of the pneumonia cases.

Setting: 450-bed teaching community hospital.

Determination of cell line suitability for rapid isolation of herpes simplex virus.

Herpes simplex virus (HSV) is one of the most commonly identified viruses in the clinical laboratory. HSV is of clinical consequence because of its ability to produce such life-threatening infections as encephalitis and neonatal disease. A variety of cell lines are currently being used for detection of HSV in cell culture.