Kainic acid lesions to the lateral tegmental field of medulla: effects on cough, expiration and aspiration reflexes in anesthetized cats.

We have tested the hypothesis that neurons of both the ventral reticular nucleus and the adjacent parts of the lateral tegmental field (LTF) may be important for the production of motor programs associated with cough, expiration and aspiration reflexes. Our studies were conducted on non-decerebrate, spontaneously breathing cats under pentobarbitone anesthesia. Dysfunction of the medullary LTF region above the obex, produced by uni- or bilateral injections of kainic acid (a neurotoxin), regularly abolished the cough reflex evoked by mechanical stimulation of both the tracheobronchial and laryngeal regions and in most cases also the expiration reflex induced from the glottal area.

Effects of medullary midline lesions on cough and other airway reflexes in anaesthetized cats.

The involvement of rapheal and medial parts of the medullary reticular formation in both generation of airway reflexes and changes in breathing were studied in 18 chloralose or pentobarbitone anaesthetized, non-paralyzed cats. Chemical lesions to the medullary midline region (0-4 mm rostral to the obex) produced by localized injections of the neurotoxin kainic acid regularly abolished the cough reflexes evoked from the tracheobronchial and laryngopharyngeal regions and in most cases also the expiration reflex induced from the glottal area. The aspiration reflex elicited from the nasopharynx was spared, but was less intense.

Quantitative analysis of myelinated nerve fibers of peripheral nerve in streptozotocin-induced diabetes mellitus.

The purpose of this study was to examine morphometric changes of myelinated fibers in early stages of experimental diabetes mellitus. Adult male Wistar rats aged 17 wk were used in this study. Diabetes mellitus was induced by streptozotocin.

Effects of focal cooling of medulla oblongata structures on quiet breathing in cats.

Experiments were carried out on 16 anaesthetized, non-paralysed cats to determine the effects of unilateral, successive focal cooling of the nuclei of the dorsal and ventral respiratory groups (DRG, VRG) of the medulla oblongata on quiet breathing parameters. The results of cold block tests of the respiratory nuclei showed that: 1. Compared with the control state, cooling of the ventrolateral part of the nucleus solitarii (vl.

[Review of the morphological changes in peripheral nerves in experimental diabetes mellitus].

A survey of morphological changes of myelinated nerve fibers of peripheral nerves recorded in experimental streptozotocin induced diabetes mellitus in rats is presented. Causes of discordant interpretations of findings are considered and pathogenetic mechanisms involved in morphological changes of myelinated nerve fibers of peripheral nerves observed in this model of diabetes mellitus are discussed. (Ref.