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R Druga

Publications and source records attributed to R Druga.

At least 37 records · Page 2Linked to original sources
PubMed1997

Projections of auditory cortex onto the inferior colliculus in the rat.

The organization of the neocortical projection to the inferior colliculus (IC) was studied in 36 rats using retrograde transport of horseradish peroxidase (HRP) or horseradish peroxidase conjugated with lectin (WGA-HRP). Projection to the external and dorsal cortices originates in the temporal neocortical areas Te 1, Te 2 and Te 3 and in the parietal area Par 2. The corticocollicular projection is predominantly ipsilateral with a weak contralateral contribution. Projection to the rostromedial and rostrolateral part of the external cortex (EC) of the IC arises mainly from the areas Par 2 and Te 1. The participation of the cortical areas Te 2 and Te 3 in this projection is only small. The fibres to the caudobasal part of the external cortex descend from the caudal parts of areas Te 1, Te 2, and Te 3. The corticocollicular projections to the dorsal part of the IC are more numerous than the projections to the EC and originate in all temporal areas, i.e. in area Te 1, Te 2 and Te 3. However, the topographical organization of the corticocollicular projection is more pronounced in the part which projects to the EC. We suggest that the topographical organization of the projections to the EC corresponds with the map of auditory space in the EC. The source of corticocollicular fibres are exclusively neurones of lamina V of all cortical areas sending their fibres to the IC.

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PubMed1993

NADPH-diaphorase activity in the central auditory structures of the rat.

Distribution of NADPH-diaphorase (NADPH-d) positive neurones was investigated in the central auditory structures of the rat. NADPH-d positive perikarya were found in the dorsal and external cortices of the inferior colliculus and in the intercollicular commissure. Within the medial geniculate body (MGB), stained cell bodies were observed in the dorsal part of the suprageniculate nucleus and in the basal part of the medial division of the MGB. Occurrence of the NADPH-d positive perikarya in the MGB is limited to its caudal third. NADPH-d positive cells are dispersed in the auditory temporal cortex within layers II-VI, with a slight prevalence in the infragranular layers. NADPH-d positive neurones have smooth dendrites without stained dendritic spines.

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PubMed1993

Distribution of the nigropallidal neurons in the rat. (An experimental study using HRP and iron-dextran).

The distribution of nigral neurons retrogradely labelled from the globus pallidus was studied in 9 rats using the horseradish peroxidase and the iron-dextran labelling technique. Retrogradely labelled neurons significantly prevailed in the ipsilateral substantia nigra pars compacta. Labelled neurons localized in the ipsilateral substantia nigra pars compacta were demonstrated throughout the anteroposterior extent of the nucleus and prevailed in its lateral half. A small number of labelled neurons was found in the lateral part of the ipsilateral substantia nigra pars reticulata, in the ipsilateral ventral tegmental area and in the contralateral substantia nigra pars compacta. A considerable perikaryal polymorphism and differences in the size are characteristic of the nigral neurons labelled from the globus pallidus.

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PubMed1992

Nigrostriatal projections in the rat as demonstrated by retrograde transport of horseradish peroxidase. II. Projection to the caudal striatum.

The distribution of nigral neurons projecting to the caudal and basal parts of the striatum was studied in 9 rats by means of the horseradish peroxidase labelling technique. Labelled neurons localized in the substantia nigra pars compacta were demonstrated throughout the antero-posterior extent of the nucleus. Most of them were found in the lateral half of the SNc. Labelled neurons localized in the substantia nigra part reticulata predominated in the caudolateral part of the SNr. Characteristic features included major perikaryal polymorphism and size range of the nigrostriatal neurons.

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PubMed1991

Thalamocaudate projections in the macaque monkey (a horseradish peroxidase study).

The distribution of thalamocaudate neurons was studied in four macaque monkeys (Macaca mulatta) using the method of retrograde horseradish peroxidase (HRP Sigma VI) transport following previous aspiration of part of the frontal cortex and subcortical white matter covering the head of the caudate nucleus. After HRP injections into the head of the caudate nucleus we found retrogradely labelled neurons mainly in the intralaminar nuclei (nc. paracentralis, nc. centralis lateralis, nc. parafascicularis) and in the midline nuclei (nc. parataenialis, nc. centralis pars densocellularis, nc. centralis superior, nc. centralis intermedialis, nc. centralis inferior, nc. reuniens). Some labelled neurons were seen in the anterior thalamic nuclei (nc. anterodorsalis, nc. anteromedialis, nc. anteroventralis). In the ventral thalamus labelled neurons were seen in the nc. ventralis anterior (pars magnocellularis) and in the nc. ventralis lateralis (pars medialis). Some labelled neurons were distributed in the marginal parts of the nc. mediodorsalis. As for the caudal portion of the thalamus, labelled neurons were found in the nc. pulvinaris medialis and nc. limitans. The thalamocaudate projection is an exclusively ipsilateral projection system. The position of the thalamocaudate neurons coincides, to a certain degree, with the termination intrathalamic area of the nigrothalamic and tectothalamic projections arising from the deep layers of the superior colliculus.

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PubMed1990

Claustro-neocortical projections in the rhesus monkey (projections to area 6).

The distribution of claustral neurons projecting to area 6 on the convexity and medial wall of the hemisphere was studied in four macaque monkeys. In all cases, HRP-positive neurons were found almost throughout the antero-posterior extent of the claustrum in its dorsal half. Following HRP injections in area 6 on the medial wall of the hemisphere most of the labelled neurons were found in the dorsal and dorsolateral portions of the claustrum. After injections in area 6 on the hemispheral convexity, labelled neurons predominated in about the middle third of the vertical extent of the claustrum. Perikaryal polymorphism and considerable differences in perikaryal size are features characteristic of claustral neurons projecting to area 6. There is a preponderance of labelled neurons whose perikarya are noted for their multipolar or pyramidal (triangular) shape. Oval and spindle-shaped neurons were found less frequently. The size of the perikarya ranged from 11 to 26 microns while most of the labelled neurons had perikarya ranging form 14 to 18 microns in size.

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PubMed1989

Nigrostriatal projections in the rat as demonstrated by retrograde transport of horseradish peroxidase. I. Projections to the rostral striatum.

The distribution of nigral neurons projecting to the rostral part of the striatum was studied in 12 rats using the horseradish peroxidase or the wheatgerm lectin bound horseradish peroxidase labelling techniques. Labelled neurons localized in the substantia nigra pars compacta (SNc) were demonstrated throughout the anteroposterior extent of the nucleus. Most of the labelled neurons were localized in the medial half of the SNc, predominantly in its basal part. Labelled neurons localized in the substantia nigra pars reticulata (SNr) predominated in the caudal half of the nucleus where they were found in its medial, central and lateral parts. A quantitative evaluation of the shape and size of the labelled neurons showed no statistically significant differences between the SNc and SNr as to the shape of the labelled perikarya. In contrast, nigrostriatal neurons in the SNc were found to have larger perikarya than their counterparts in the SNr.

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PubMed1989

Projections from the claustrum to the occipital cortex in the guinea pig.

The existence of ipsilateral claustrocortical projection to the occipital area Oc 2.2 (Wree et al. 1981) was demonstrated in four guinea pigs. The neurons labelled by retrogradely transported HRP were localized in the caudal half of the claustrum dorsale (in its dorsomedial and central part); small and medium-sized oval and multipolar neurons preponderated.

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PubMed1989

[Experimental injuries of the spinal cord].

The authors present the results of five years' research concerned with experimental injuries of the spinal cord. The authors studied in cats and rabbits four types of problems: 1. the dynamics of injuries of the spinal cord from the morphological and biochemical aspect, in particular the development and shape of the lesion after complete severing of the spinal cord at the L2 level which was performed by 10-second extradural compression of the spinal cord with an artery forceps. 2. The possibility of resection of the destroyed spinal tissue one week after the insult and the development of autodestructive processes after this resection. 3. Resection of the entire vertebra L2 in healthy animals and shortening of the spine by means of an original stabilization apparatus. 4. Resection of the vertebra, resection of the autodestroyed parts of the spinal cord and approximation of the stumps of the spinal cord by shortening the spine. The assembled findings are discussed in conjunction with contemporary research into the reconstruction of spinal functions and possible transplantations of the CNS.

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PubMed1985

[Neurons forming striatonigral connections in the rat brain].

Using the retrograde axonic transport of horseradish peroxidase method the striatal neurons projections to substance nigra have been studied in rats. After peroxidase injection into substance nigra a considerable number of small and medium sized neurons (10-20 mkm) become labelled in the ipsilateral striatum. Large labelled striatal cells (20-25 mkm) have been found. Among labelled striatal neurons multipolar cells with triangular and oval body prevailed. The number of cells with elongated multipolar or spindle-shaped body was less. The data obtained disprove the conception that only large ("giant") neurons form the efferent striatal pathways to substance nigra.

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PubMed1984

Projections from auditory structures to the superior colliculus in the rat.

Auditory inputs to the middle and deep layers of the central area of the superior colliculus were studied in rats with horseradish peroxidase (HRP) injections into the superior colliculus. The most powerful projections were found from the dorsal nucleus of the lateral lemniscus bilaterally, with prevailing ipsilateral projections. A smaller number of labelled cells was observed in the ipsilateral external nucleus of the inferior colliculus and a few labelled cells were distributed in the dorsomedial part of the inferior colliculus ipsilaterally. Descending connections from the auditory cortex originated from the dorsal part of the ipsilateral auditory cortical area, in layer Vb.

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