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The functional states of the thalamus and the associated neuronal interplay.

The glucose oxidase-DAB-nickel method in peroxidase histochemistry of the nervous system.

Specificity in the projection patterns of accumbal core and shell in the rat.

The organization of noradrenergic pathways from the brainstem to the paraventricular and supraoptic nuclei in the rat

Recent data have emphasized the neurochemically distinct nature of subterritories in the accumbens part of the rat ventral striatum termed the core, shell, and rostral pole. In order to gain a more comprehensive understanding of how afferents are distributed relative to these subterritories, immunohistochemical detection of retrogradely transported Fluoro-Gold was carried out following iontophoretic injections intended to involve selectively one of the subterritories. The data revealed that a number of cortical afferents of the medial shell and core originate in separate areas, i.e., the dorsal peduncular, infralimbic, and posterior piriform cortices (to medial shell) and the dorsal prelimbic, anterior agranular insular, anterior cingulate, and perirhinal cortices (to core). The lateral shell and rostral pole are innervated by cortical structures that also project either to the medial shell or core. The orbital, posterior agranular insular, and entorhinal cortices, hippocampus, and basal amygdala were observed to innervate the accumbens in a topographic manner. Following core injections, strong bilateral cortical labeling was observed. Few labeled cortical cells were observed contralaterally following injections in the medial shell. Intermediate numbers of labeled neurons were observed in contralateral cortices following lateral shell injections. Robust subcortical labeling in a variety of structures in the ventral forebrain, lateral hypothalamus, deep temporal lobe, and brainstem was observed after shell injections, particularly those that involved the caudal dorsomedial extremity of the shell, i.e., its "septal pole." Selective ipsilateral labeling of subcortical structures in the basal ganglia circuitry was observed following injections in the core and, to a lesser extent, lateral shell. It was concluded that a number of afferent systems exhibit varying degrees of segregation with respect to the accumbal subterritories.

The patterns of afferent innervation of the core and shell in the “Accumbens” part of the rat ventral striatum: Immunohistochemical detection of retrogradely transported fluoro‐gold

Application of coupled oxidation reaction to electron microscopic demonstration of horseradish peroxidase: cobalt-glucose oxidase method

Topographical localization of monotoneurons supplying the masticatory muscles was investigated in the cat and rat, utilizing retrograde axonal transport of horseradish peroxidase. Following injection of horseradish peroxidase in each masticatory muscle, motoneurons labelled with peroxidase were seen to be aggregated into a cluster within the motor nucleus of the trigeminal nerve. Such clusters of peroxidase-motoneurons innervating each masticatory muscle were demarcated more sharply in kittens than in adult animals. The pattern of the nuclear representation of the masticatory muscles was found to be essentially the same in the cat and rat; it could be summarized as follows: The motor nucleus of the trigeminal nerve could be divided cytoarchitectonically into the dorsolateral and ventromedial divisions; the former was seen in almost the whole rostrocaudal extent of the nucleus, while the latter was localized at the levels of caudal two thirds of the nucleus. In the dorsolateral division, the temporal muscle was represented dorsally and dorsomedially, the masseter muscle ventrolaterally, and the pterygoid muscles ventromedially. In the ventromedial division, the anterior digastric muscle was represented dorsomedially, and the mylohyoid muscle ventrolaterally. It was also confirmed that the motoneurons supplying the posterior digastric muscle were localized in the accessory facial nucleus.

Localization of masticatory motoneurons in the cat and rat by means of retrograde axonal transport of horseradish peroxidase

Localization of motoneurons innervating perineal muscles: a HRP study in cat

Premotor neurons sending their axons to the trigeminal motor nucleus were observed in the cat by light and electron microscopy after labeling the neurons retrogradely or anterogradely with horseradish peroxidase (HRP)



After HRP injection into the trigeminal motor nucleus, retrogradely labeled neurons were seen most frequently in the parvocellular reticular formation bilaterally Many labeled neurons were also seen contralaterally in the intermediate zone at the rostralmost levels of the cervical cord and its rostral extension into the caudalmost levels of the medulla oblongata Additionally, some neurons were labeled ipsilaterally in the mesencephalic tri-geminal nucleus, contralaterally in the main sensory trigeminal nucleus and the trigeminal motor nucleus, and bilaterally in the oral and interpolar sub-nuclei of the spinal trigeminal nucleus Only a few labeled neurons were seen in the confines of the gigantocellular reticular formation All labeled neurons were small or of medium size; no large neurons were labeled



After HRP injection into the regions around the trigeminal motor nucleus or the parvocellular reticular formation, axodendritic terminals containing HRP granules were found contralaterally within the trigeminal motor nucleus Some of these labeled terminals were filled with round synap-tic vesicles and others contained pleomorphic synaptic vesicles The varied morphology of labeled axon terminals was considered to reflect the functional heterogeneity of the premotor neurons for the trigeminal motor nucleus

A light and electron microscopic study of premotor neurons for the trigeminal motor nucleus

Central distribution of afferent and efferent components of the pudendal nerve was examined in the cat by the HRP method after applying HRP to the central cut end of the pudendal nerve.



Retrogradely labeled neuronal cell bodies were located primarily in the feline homologue of the Onuf's X nucleus, constituting a slender longitudinal cell column in the ventral horn of the S1 and S2 cord segments. The Onuf's nucleus was present constantly from middle S1 to high S2 cord segments, and occasionally extended rostrally to high S1 or low L7, and caudally to middle S2, low S2, or high S3 cord segments. No sex differences were observed in the distribution pattern, number, and soma size of labeled neurons in the Onuf's nucleus.



Transganglionically labeled dorsal root fibers were found to terminate ipsilaterally in the lamina I of the dorsal horn at levels of lower lumbar, sacral, and higher coccygeal cord segments and the gracile nucleus, and bilaterally with an ipsilateral predominance in the dorsal commissural gray and laminae III, IV, V, and VI of the dorsal horn at levels of lower lumbar, sacral, and higher coccygeal cord segments. Some labeled dorsal root fibers appeared to end ipsilaterally in the regions where the sacral parasympathetic preganglionic neurons have been shown to be located.

Akira Konishi

Papers

Application of coupled oxidation reaction to electron microscopic demonstration of horseradish peroxidase: cobalt-glucose oxidase method

Localization of masticatory motoneurons in the cat and rat by means of retrograde axonal transport of horseradish peroxidase

Localization of motoneurons innervating perineal muscles: a HRP study in cat

A light and electron microscopic study of premotor neurons for the trigeminal motor nucleus

Central distribution of afferent and efferent components of the pudendal nerve in cat.