Search results for "Neuronal tracing"
showing 10 items of 11 documents
The brainstem efferent acoustic chiasm in pigmented and albino rats
2015
Abstract The present study examined whether structural peculiarities in the brain-efferent pathway to the organ of Corti may underlie functional differences in hearing between pigmented and albino individuals of the same mammalian species. Pigmented Brown-Norway rats and albino Wistar rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani of the cochlea to identify olivocochlear neurons (OCN) in the brainstem superior olivary complex. After five days, brains were perfusion-fixed and brainstem sections were cut and analyzed with respect to retrogradely labeled neurons. Intrinsic neurons of the lateral system were lo…
Differential efferent projections of the anterior, posteroventral, and posterodorsal subdivisions of the medial amygdala in mice
2012
The medial amygdaloid nucleus (Me) is a key structure in the control of sociosexual behaviour in mice. It receives direct projections from the main and accessory olfactory bulbs, as well as an important hormonal input. To better understand its behavioural role, in this work we investigate the structures receiving information from the Me, by analysing the efferent projections from its anterior (MeA), posterodorsal (MePD) and posteroventral (MePV) subdivisions, using anterograde neuronal tracing with biotinylated and tetrametylrhodamine-conjugated dextranamines.The Me is strongly interconnected with the rest of the chemosensory amygdala, but shows only moderate projections to the central nucl…
Olfacto-retinalis pathway in Austrolebias charrua fishes: A neuronal tracer study
2013
Abstract The olfacto-retinal centrifugal system, a constant component of the central nervous system that appears to exist in all vertebrate groups, is part of the terminal nerve (TN) complex. TN allows the integration of different sensory modalities, and its anatomic variability may have functional and evolutionary significance. We propose that the olfacto-retinal branch of TN is an important anatomical link that allows the functional interaction between olfactory and visual systems in Austrolebias . By injecting three different neuronal tracers (biocytin, horseradish peroxidase, and 1,1′-dioctadecyl-3,3,3′,3′tetramethyl-indocarbocyanine perchlorate (DiI)) in the left eye of Austrolebias ch…
Anterograde tracing of retinohypothalamic afferents with Fluoro-Gold
1997
The anterograde neuronal tracing properties of Fluoro-Gold (FG) were characterized in this study by its ability to label the retinohypothalamic tract (RHT) upon pressure injection of the substance into the vitrous body of the eye in the Djungarian hamster, Phodopus sungorus. Tracing was compared to the anterograde neuronal transport of cholera toxin B subunit (CTB), Fast blue (FB), Phaseolous vulgaris leucoagglutinin (PHA-L) and biocytin. After survival times that ranged from 24 h to 4 weeks, a major projection was found to the bilateral hypothalamic suprachiasmatic nuclei (SCN). Labeling was also found in the anterior medial preoptic nucleus and, in relatively sparse amounts, in the latera…
Spinal relay neurons for central control of autonomic pathways in a photoperiodic rodent.
2021
Location and distribution of spinal sympathetic preganglionic neurons projecting to the superior cervical ganglion were investigated in a rodent model organism for photoperiodic regulation, the Djungarian hamster (Phodopus sungorus). Upon unilateral injection of Fluoro-Gold into the superior cervical ganglia, retrograde neuronal tracing demonstrated labeled neurons ipsilateral to the injection site. They were seen in spinal segments C8 to Th5 of which the segments Th1 to Th3 contained about 98% of the labeled cells. Neurons were found in the spinal cord predominantly in the intermediolateral nucleus pars principalis and pars funicularis. At the same time, the central autonomic area and the …
Neurochemistry of olivocochlear neurons in the hamster.
2009
The present study was conducted to characterize the superior olivary complex (SOC) of the lower brain stem in the pigmented Djungarian hamster Phodopus sungorus. Using Nissl-stained serial cryostat sections from fresh-frozen brains, we determined the borders of the SOC nuclei. We also identified olivocochlear (OC) neurons by retrograde neuronal tracing upon injection of Fluoro-Gold into the scala tympani. To evaluate the SOC as a putative source of neuronal nitric oxide synthase (nNOS), arginine-vasopressin (AVP), oxytocin (OT), vasoactive intestinal polypeptide (VIP), or pituitary adenylate cyclase-activating polypeptide (PACAP) that were all found in the cochlea, we conducted immunohistoc…
A nitrergic projection from the superior olivary complex to the inferior colliculus of the rat
2003
The present study was conducted to test whether the ascending auditory projection from the superior olivary complex (SOC) of the brainstem to the inferior colliculus (IC) may use nitric oxide (NO) as a neuroactive compound. We identified olivo-collicular projection neurons in subnuclei of the SOC by retrograde neuronal tracing with Fluoro-Gold (FG) injected into the central nucleus of the IC. Sections containing retrograde labelled neurons were subjected to immunohistochemical incubation in an antiserum directed against the enzyme responsible for NO production in nerve cells, neuronal NO synthase (nNOS). The analysis showed that FG-containing neurons as well as nNOS-immunoreactive neurons w…
Modeling Vestibular Compensation: Neural Plasticity Upon Thalamic Lesion.
2020
The present study in rats was conducted to identify brain regions affected by the interruption of vestibular transmission and to explore selected aspects of their functional connections. We analyzed, by positron emission tomography (PET), the regional cerebral glucose metabolism (rCGM) of cortical, and subcortical cerebral regions processing vestibular signals after an experimental lesion of the left laterodorsal thalamic nucleus, a relay station for vestibular input en route to the cortical circuitry. PET scans upon galvanic vestibular stimulation (GVS) were conducted in each animal prior to lesion and at post-lesion days (PLD) 1, 3, 7, and 20, and voxel-wise statistical analysis of rCGM a…
Connections of the amygdaloid structures integrating olfactory and vomeronasal information in mice
2015
La amígdala es considerada una estructura clave en el aprendizaje emocional asociativo en roedores. La mayor parte de los estudios sobre aprendizaje emocional se han centrado en paradigmas de aprendizaje aversivo, cuando al menos, parte de la amígdala es también relevante en el procesamiento de estímulos reforzantes, particularmente estímulos de naturaleza química (olores y feromonas), dado que los roedores son animales macrosmáticos. La amígala es primer relevo telencefalico en donde convergen las proyecciones provenientes del bulbo olfatorio principal (MOB), que es activado por volátiles y del bulbo olfatorio accesorio (AOB), que es activado por no volátiles. Nuestro estudio se centra en …
Trigeminal innervation of the mammalian pineal gland.
1999
There is evidence that the trigeminal (Gasserian) ganglia innervate the mamma- lian pineal gland and serve in its regulation in addition to the sympathetic and cholinergic as well as further influences. By means of immunohistochemical methods, previous studies demonstrated fibers containing calcitonin gene-related peptide (CGRP-LI) or substance P (SP) in the superficial pineal of various mammalian species. In addition, SP and the related tachykinin, neurokinin A, were detected by radioimmunoassay and HPLC, respectively, in the rat and human pineal gland. In the present study, retrograde neuronal tracing upon injection of a tracer substance into the superfical pineal gland of rats was used i…