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Dense Innervation (dense + innervation)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Inflammatory nerve responses in the dental pulp

ENDODONTIC TOPICS, Issue 1 2007
INGE FRISTAD
Tooth pulp has a dense innervation and a rich vascular supply to maintain homeostasis and to preserve the integrity of the tissue. Function, trauma, and antigenic challenges make teeth and supporting tissues susceptible to tissue injury and inflammation, partially due to the lack of collateral blood and nerve supply and to their low compliance. This review focuses on dental nerve functions and adaptive changes in the pulpal nerve supply following inflammation and peripheral injury. Overviews of dental innervation and its development and of the peptidergic innervation of oral tissues are presented, followed by a discussion of peripheral and central changes after local insults to teeth and peripheral nerve injuries. The functional implications of these adaptive changes are considered. Received 13 February 2009; accepted 3 September 2009. [source]

Gender-related changes in the avian vasotocin system during ontogeny

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2001
Aleksandr Jurkevich
Abstract The arginine vasotocin (AVT) system of the avian brain includes a sexually dimorphic part that extends from the caudal part of preoptic region through the medial part of the bed nucleus of stria terminalis (BSTm) to the lateral septum. It is composed of the parvocellular neurons located in the BSTm and the dense innervation of the medial preoptic region and lateral septum. In this part of the brain, AVT expression is stronger in males than in females in a few bird species investigated to date. This review focuses on the ontogeny of sexual differences in the vasotocinergic system of two gallinaceous species, domestic chicken and Japanese quail, and on the role of gonadal hormones in organizing during development and maintaining in adulthood these differences. Parvocellular AVT neurons become discernible in the BSTm of males and females during the second half of embryonic development. These cells undergo a profound and irreversible sexual differentiation during ontogenetic development. Recent findings demonstrate a dual role of estrogens in the organization and activation of sex differences in the AVT system. During the embryonic period of ontogeny, estrogens differentiate the AVT system in a sexually dimorphic manner in parallel with the differentiation of sexual behavior, while in adulthood estrogens, locally produced from testosterone in the male brain, activate AVT synthesis in the BSTm. The sexually dimorphic part of the AVT system is sensitive to a number of abiotic factors such as light, temperature, and water availability. It is suggested that sex dimorphic vasotocinergic systems could be implicated in processes of social recognition in various behavioral contexts. Microsc. Res. Tech. 55:27,36, 2001. © 2001 Wiley-Liss, Inc. [source]

Effects of age and GDNF on noradrenergic innervation of the hippocampal formation: Studies from intraocular grafts

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 5 2001
A.-C. Granholm
Abstract Recent studies have suggested that factors in the target tissue influence the degree of plasticity and regeneration following aging and/or specific insults. We have investigated whether young or aged targets differ in their noradrenergic innervation from fetal locus coeruleus (LC) neurons, and also if a specific growth factor, glial cell line-derived neurotrophic factor (GDNF) can affect this innervation pattern. Tissue pieces of fetal brainstem and young (3 months) or old (18 months) iris tissue were transplanted simultaneously into the anterior chamber of the eye of adult hosts. We found that aged iris transplants became innervated to a significantly lesser degree by the cografted LC neurons than young iris transplants. Fetal hippocampal tissue was then grafted to adult hosts, and a fetal brainstem graft containing LC neurons was placed adjacent to the first graft, either at 3 or 21 months post-grafting. Thus, old/young chimeras of the noradrenergic coeruleo-hippocampal pathway were created. Aged hippocampal grafts received a much less dense innervation from co-grafted LC neurons than young hippocampal grafts. Tyrosine hydroxylase-positive-immunoreactive innervation was only found in the outskirts of aged grafts, while the young hippocampal grafts contained an even innervation pattern. The innervation density of hippocampal grafts was significantly enhanced by GDNF treatment. These findings demonstrate that target-derived factors may regulate neuronal plasticity, and that the age of the target is more important for innervation properties than the age of the neuron innervating a particular target. Microsc. Res. Tech. 54:298,308, 2001. © 2001 Wiley-Liss, Inc. [source]

Retrograde adenoviral vector targeting of nociresponsive pontospinal noradrenergic neurons in the rat in vivo

THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 2 2009
Patrick W. Howorth
Abstract The spinal dorsal horn receives a dense innervation of noradrenaline-containing fibers that originate from pontine neurons in the A5, locus coeruleus (LC), and A7 cell groups. These pontospinal neurons are believed to constitute a component of the endogenous analgesic system. We used an adenoviral vector with a catecholaminergic-selective promoter (AVV-PRS) to retrogradely label the noradrenergic neurons projecting to the lumbar (L4,L5) dorsal horn with enhanced green fluorescent protein (EGFP) or monomeric red fluorescent protein (mRFP). Retrogradely labeled neurons (145 ± 12, n = 14) were found in A5-12%, LC-80% and A7-8% after injection of AVV-PRS-EGFP to the dorsal horn of L4,L5. These neurons were immunopositive for dopamine ,-hydroxylase, indicating that they were catecholaminergic. Retrograde labeling was optimal 7 days after injection, persisted for over 4 weeks, and was dependent on viral vector titer. The spinal topography of the noradrenergic projection was examined using EGFP- and mRFP-expressing adenoviral vectors. Pontospinal neurons provide bilateral innervation of the cord and there was little overlap in the distribution of neurons projecting to the cervical and lumbar regions. The axonal arbor of the pontospinal neurons was visualized with GFP immunocytochemistry to show projections to the inferior olive, cerebellum, thalamus, and cortex but not to the hippocampus or caudate putamen. Formalin testing evoked c-fos expression in these pontospinal neurons, suggesting that they were nociresponsive (A5-21%, LC-16%, and A7-26%, n = 8). Thus, we have developed a viral vector-based strategy to selectively, retrogradely target the pontospinal noradrenergic neurons that are likely to be involved in the descending control of nociception. J. Comp. Neurol. 512:141,157, 2009. © 2008 Wiley-Liss, Inc. [source]