Histochemical mapping of succinic dehydrogenase and cytochrome oxidase in the diencephalon and basal telencephalic centers of the brain of squirrel monkey (Saimiri sciureus)

Summary The distribution of succinic dehydrogenase (SDA) and cytochrome oxidase (Cy. O) was mapped in the various diencephalic nuclei and basal telencephalic centers of the squirrel monkey brain. Thirty thick formaldehyde fixed serial sections were also studied for the delineation of the various nuclei, but histochemical preparations proved equally useful for this purpose. Strong SDA and Cy. O activity were observed in the habenular, pulvinaris, anterior dorsalis and ventralis, lateralis dorsalis and posterior, and ventral posterior nuclei. The corpus geniculatum laterale and mediale also showed a strong reaction for these enzymes. The nucleus ventralis anterior, which occupies a very large area in the rostral part of the thalamus, showed moderately strong activity in the cellular patches and negligible activity in the thick fiber bundles passing through it. A comparatively weak reaction was observed in the midline thalamic nuclei. The nucleus caudatus and putamen, however, showed very strong SDA/Cy. O activity. The hypothalamic nuclei showed mild Cy. O and moderate SDA reactions, except for the nucleus ventromedialis hypothalami. The latter showed a little stronger enzyme reaction. The fibers of the internal capsule and the anterior commissure showed little SDA and mild Cy. O activity. The various nuclei of the amygdaloid complex showed similar histochemical reactions with moderate SDA and mild Cy. O activity.This work has been carried out with the aid of Grant No. 00165 from the Animal Resources Branch, National Institutes of Health, and a grant from the National Foundation for Neuro-Muscular Diseases and Nasa Grant NGR-11-001-016.     

Organization of the thalamic and cortical projections of the cat neostriatum]

The investigation has demonstrated that in the cat the nucleus caudatus and the putamen are projected on the cortex and thalamic nuclei of the ipsilateral hemisphere according to a certain topical principle characterized by both similarity in localization of projections of these two structures of the neostriatum and their difference. On the one hand, to the same fields of the cortex and the thalamic nuclei fibres from both structures of the neostriatum go, and on the other hand--a number of cortical zones and thalamic nuclei get projections either from the nucleus caudatus or from the putamen only. Owing to a certain organization of the connections studied, it is possible to consider them as the base of functional heterogeneity of the basal ganglia. Over-lapping of the cortical and thalamic projections of the nucleus caudatus and the putamen might explain common striatal effects on behavioral reactions.     

Fronto-striatal correlations in normal and pathologic aging of the human brain

In psychically healthy persons of three age groups (30-40, 50-60, 80-90 years), as well as in those suffering from Alzheimer's disease (50-60 years) right and left hemispheres formations, including into a single functional system (fields 8, 10, 47 and the nucleus caudatus) have been investigated. Using the series of frontal paraffin sections 20 mcm thick, stained after Nissl and Bielschowsky methods, cyto-glioarchitectonics and neuronal composition of the structures mentioned have been studied. In 0.001 mm3 of the brain substance, in cortical layers II and V and in the nucleus caudatus head density of neurons, perineuronal glia, neurons with lipofuscin, size of the neurons have been calculated. Various degree of manifestation of morphological changes is revealed in different stages of the single functional system. These changes are directly proportional to the organizational level of the structures studied and depend on the stage of the process, on accompanying diseases and individual peculiarities of the person. They are more intensive in the frontal fields and weaker in the nucleus caudatus. At Alzheimer's disease they are more distinct in the associative fields 10 and 47, at normal ageing--in the motor structures--in the field 8 and then in the nucleus caudatus. Spreading of the pathological process occurs with a predominant damage of neurons of cholinergic origin.     

Connections between the anterior thalamic nuclei in turtles (data of the peroxidase method)

It turtles, Testudo horsfieldi (Gray) connections of anterior dorsomedial and dorsolateral thalamic nuclei have been investigated by means of horseradish peroxidase, injected ionophoretically. Retrogradely labelled neurons are predominantly revealed ipsilaterally in the cerebral structures belonging to the limbic system: in the forebrain--basal parts of the hemisphere, septum, adjoining nucleus, nuclei of the anterior and hippocampal commissures, hippocampal cortex, preoptic area; in the diencephalon--in the subthalamus (suprapeduncular nucleus), in some hypothalamic structures (para- and periventricular nuclei, posterior nucleus, lateral hypothalamic area, mamillary complex); in the brain stem--ventral tegmental area, superior nucleus of the suture. Less vast connections are with nonlimbic cerebral formations: projections to the striatum, afferents from the laminar nucleus of the acoustic torus, nuclei of the posterior commissure. Similarity and difference of the nuclei investigated in the turtles with the thalamic anterior nuclei in lizards, with the anterior and intralaminar nuclei in Mammalia are discussed. An idea is suggested on functional heterogeneity of the anterior nuclei in reptiles and on their role for ensuring limbic functions at the thalamic level.     

Efferent projections from the lateral geniculate nucleus to the pineal complex of the Mongolian gerbil (Meriones unguiculatus)

Summary The intergeniculate leaflet of the lateral geniculate nucleus is considered to modulate circadian activity rhythms probably mediated by a direct neuronal connection to the suprachiasmatic nucleus. The present study in the gerbil demonstrates, by anterograde tracing with Phaseolus vulgaris-leucoagglutinin (PHA-L), the existence of an additional neuronal projection from a subportion of the lateral geniculate nucleus, involving the intergeniculate leaflet, directly to the pineal gland. PHA-L-immunoreactive nerve fibers originating from perikarya at the injection site were located under the optic tract projecting towards the midsagittal plane. Delicate PHA-L-immunoreactive nerve fibers were observed in the posterior paraventricular thalamic nucleus, precommissural nucleus, olivary pretectal nucleus, anterior and posterior pretectal nuclei, and posterior commissure. Single fibers could be followed from the caudal part of the medial habenular nucleus and the pretectal area into the rostral part of the deep pineal gland. Other fibers continued through the posterior commissure into the contralateral hemisphere to terminate in the same structures as on the ipsilateral side. From the posterior commissure, small bundles of thick fibers entered the deep pineal gland where they arborized among the endocrine cells. A few nerve fibers were observed in the habenular commissure and the pineal stalk, but no fibers were identified in the superficial pineal. This direct geniculo-pineal connection suggests that the pineal gland is directly influenced by the optic system.     

Central connections of the olfactory bulb in the weakly electric fish,Gnathonemus petersii

Summary We have investigated the central connections of the classical olfactory system in the weakly electric fish Gnathonemus petersii using HRP and cobalt labelling techniques. The olfactory bulb projects bilaterally via the medial and lateral olfactory tracts to restricted areas of the telencephalon, namely to its rostromedial, lateral and posterior medial parts. The most extensive telencephalic target is the posterior terminal field, which arcs around the lateral forebrain bundle at levels posterior to the anterior commissure. Projections to the contralateral hemisphere cross in the ventral telencephalon rostral to the anterior commissure and via the posterior dorsal part of the anterior commissure; endings are also present within the anterior commissure. Bilateral projections to the preoptic area, to the nucleus posterior tuberis and to an area in the thalamus are apparent. In all cases, contralateral projections are less extensive than those on the side ipsilateral to the injected bulb. A projection via the medial olfactory tract can be followed to the contralateral bulb. Following injections into the olfactory bulb, retrogradely labelled neurons are found in the contralateral bulb and in six telencephalic areas; they are also present in the periventricular diencephalon and in an area lateral to the nucleus posterior tuberis. The present results support the suggestion that a reduction in olfactory input to the telencephalon occurs together with increased telencephalic differentiation in actinopterygian fishes.     

SALMFamide2 and serotonin immunoreactivity in the nervous system of some acoels (Xenacoelomorpha)

Acoel worms are simple, often microscopic animals with direct development, a multiciliated epidermis, a statocyst, and a digestive parenchyma instead of a gut epithelium. Morphological characters of acoels have been notoriously difficult to interpret due to their relative scarcity. The nervous system is one of the most accessible and widely used comparative features in acoels, which have a so‐called commissural brain without capsule and several major longitudinal neurite bundles. Here, we use the selective binding properties of a neuropeptide antibody raised in echinoderms (SALMFamide2, or S2), and a commercial antibody against serotonin (5‐HT) to provide additional characters of the acoel nervous system. We have prepared whole‐mount immunofluorescent stainings of three acoel species: Symsagittifera psammophila (Convolutidae), Aphanostoma pisae, and the model acoel Isodiametra pulchra (both Isodiametridae). The commissural brain of all three acoels is delimited anteriorly by the ventral anterior commissure, and posteriorly by the dorsal posterior commissure. The dorsal anterior commissure is situated between the ventral anterior commissure and the dorsal posterior commissure, while the statocyst lies between dorsal anterior and dorsal posterior commissure. S2 and serotonin do not co‐localise, and they follow similar patterns to each other within an animal. In particular, S2, but not 5‐HT, stains a prominent commissure posterior to the main (dorsal) posterior commissure. We have for the first time observed a closed posterior loop of the main neurite bundles in S. psammophila for both the amidergic and the serotonergic nervous system. In I. pulchra, the lateral neurite bundles also form a posterior loop in our serotonergic nervous system stainings.     

Central connections of the olfactory bulb in the goldfish,Carassius auratus

Summary The central connections of the goldfish olfactory bulb were studied with the use of horseradish peroxidase methods. The olfactory bulb projects bilaterally to ventral and dorsolateral areas of the telencephalon; further targets include the nucleus praeopticus periventricularis and a caudal olfactory nucleus near the nucleus posterior tuberis in the diencephalon, bilaterally. The contralateral bulb and the anterior commissure also receive an input from the olfactory bulb. Contralateral projections cross in rostral and caudal portions of the anterior commissure and in the habenular commissure. Retrogradely labeled neurons are found in the contralateral bulb and in three nuclei in the telencephalon bilaterally; the neurons projecting to the olfactory bulb are far more numerous on the ipsilateral side than in the contralateral hemisphere. Afferents to the olfactory bulb are found to run almost entirely through the lateral part of the medial olfactory tract, while the bulb efferents are mediated by the medial part of the medial olfactory tract and the lateral olfactory tract. Selective tracing of olfactory sub-tracts reveals different pathways and targets of the three major tract components. Reciprocal connections between olfactory bulb and posterior terminal field suggest a laminated structure in the dorsolateral telencephalon.     

Efferent connections of the striatum with the Ep field of the temporal cortex in the cat

When horseradish peroxidase was injected into the Ep area of the temporal cortex of 5 cats, the distribution of the labelled neurons in the strio-pallidum and in the nucleus of Meynert was similar in all the cases. In the striatum predominantly large cells (in the nucleus caudatus and in the putamen), as well as middle and small (in the putamen) cells were labelled. Comparing the form and size of the labelled cells in the striatum, revealed in Golgi preparations, it is possible to conclude that large labelled neurons correspond to long-axonal sparsely-branching reticular neurons, and middle and small--to long-axonal densely-branching dendroid "spinular" neurons. The large cells of the striatum can be considered as a part of a vast macrocellular ascending system of the forebrain, its preservation maintains the higher integrative functions of the brain.     

Topical organization of the projections to the putamen from the nuclei of the amygdaloid body in the cat

The investigation has been performed on the cat by means of the retrograde axonal transport of horseradish peroxidase method and luminescent markers. To the putamen along its rostro-caudal length and to all the segments projection fibers get only from the neurons of the basal nucleus of the amygdaloid body, greater number of the neurons projecting to the antero-ventral parts of the putamen than to the posterior ones. The problem on likeness in organization of the projections of the amygdaloid body and the caudate nucleus is discussed.     

NPY-mRNA expressions in the nucleus accumbens,caudate putamen and cerebral cortex of apomorphine-susceptible and apomorphine-unsusceptible rats

Using the apomorphine-induced stereotyped gnawing response as a selection criterion, two distinct groups of rats can be distinguished, apomorphine-susceptible (APO-SUS) and apomorphine-unsusceptible (APO-UNSUS) rats. These two lines differ in several components of both striatal and extrastriatal areas. This study deals with the expression of neuropeptide Y (NPY)mRNA-expressing neurons in the nucleus accumbens, caudate putamen and cerebral cortex of both rat lines, using non-radioactive in situ hybridisation. The morphology of the neurons in the three regions is similar, viz. oblong, rectangular or triangular, with two or three processes. The neurons are homogeneously distributed in all regions, and in the nucleus accumbens they are particularly numerous ventrally to the anterior commissure. Using automated image analysis, the mean numerical density of NPYmRNA-positive neurons per brain region and the mean NPYmRNA expression level per neuron per brain region were determined. No differences appear in the numerical densities of NPYmRNA-containing neurons in the nucleus accumbens, caudate putamen and cortex between APO-SUS and APO-UNSUS rats. However, distinct differences between the rat lines are present in the level of NPYmRNA expression per neuron in the nucleus accumbens and in the caudate putamen, showing that NPY contributes to the differential neurochemical make-up of these rat lines that is responsible for their obvious differences in behaviour, physiology and immune competence.     

大鼠尾壳核头部生长抑素mRNA的区域性表达

目的　观察尾壳核 (CP)头部背内侧区、背外侧区、腹内侧区和腹外侧区生长抑素 (SOM )mRNA阳性神经元分布特点。方法　采用原位杂交组织化学方法。结果　CP头部不同区域SOMmRNA阳性神经元的密度存在差异 ,腹内侧区SOMmRNA阳性神经元的密度明显高于其他区 (P <0 0 1)。结论　CP头部不同区域的SOMmRNA阳性神经元密度存在差异 ,这可能是CP头部不同区域机能差异的形态学基础之一。     

Connections between the globus pallidus and putamen and the hypothalamus and subthalamus

In 16 adult cats with electrolytically destructed external and internal parts of the globus pallidus and in 8 cats with destructed putamen direct strio-pallido-hypothalamic and strio-pallido-subthalamic pathways have been studied. Degeneration of the axonal preterminals and terminals have been examined in preparations treated after Nauta--Gygax, Nauta--Laidlow, Finck--Heimer with simultaneous additional staining of the nuclei with cresyl violet after Kawamura--Niimi. Direct pallido- and putamen-hypothalamic pathways to nuclei of the grey tubercle, posterior and lateral nuclei of the hypothalamus were stated. Direct pathways from the putamen to the subthalamic nucleus have been revealed, however, these pathways are represented in less degree than those of pallido-subthalamic connections. Direct pathways from the external portion of the globus pallidus and putamen to the subthalamic nucleus are more pronounced and represented by greater numbers of projections than those of strio-pallido-hypothalamic origin.     

Selection of the optimal lesion site for the relief of parkinsonian tremor on the basis of spectral analysis of neuronal firing patterns

Techniques for quantitatively describing the firing properties of neurons have been used to identify thalamic cells with a firing pattern which is correlated with EMG activity during tremor. By locating these cells relative to the anterior border of the somatosensory nucleus and the anterior commissure-posterior commissure line, it may be possible to select the optimal lesion site for the relief of parkinsonian tremor on a rational rather than an empirical basis.     

Intrasexual and intersexual dimorphisms of the red salmon prosencephalon

Intrasexual as well as intersexual dimorphisms were found in the prosencephalon and mesencephalon of adult Oncorhynchus nerka (red/sockeye salmon). These dimorphisms are concerned with the position of the preoptic nucleus, nucleus lateralis tuberis, habenula, third ventricle, tectal ventricles, preoptic recess, recessus lateralis, horizontal commissure, posterior commissure, and toral commissure. The intrasexual dimorphism was characterized by either a rostral ("r"-pattern) or a caudal ("c"-pattern) position of the preoptic region as well as varying locations of other structures within the prosencephalon. As compared to "c"-pattern fish, the preoptic nucleus and nucleus lateralis tuberis were located more rostral, and the habenula was positioned further caudal, in "r"-type animals. The intersexual dimorphism was also characterized by different positions of the structures listed above. With the exception of the preoptic nucleus, all of these were located further rostral in "r"-pattern females than in type "r" males. In "c"-pattern females, they were positioned further caudal than in type "c" males. The number of neurons in the parvocellular and in the magnocellular portion of the preoptic region differed in the two genders with respect to "r"- as well as "c"-pattern fish. Males had more neurons than females in both the magno- and the parvocellular subdivisions of the preoptic region. In "r"- and "c"-pattern fish, the average size of magnocellular preoptic neurons was larger in females than in males. The observed intersexual variations may reflect gender-specific differences in the control of the pituitary. Functional correlates of intrasexual dimorphism are obscure.     

Structural basis of frontal cortex control of thalamic and basal nuclei in dogs

Fibrillar degeneration after extirpation of the frontal cortical field F2, central part, was observed in dogs by Nauta--Gygax and Fink--Heimer's methods. Degenerated fibrillae were stated to form two bundles and terminate near the neurons of nonspecific thalamic nuclei: n. ret, MD, pf, sprf, as well as in the neurons of specific thalamic nuclei: n. Vna, cgl, cgm, pul. Degenerated processes of the frontal cortex cells projected to the neurons of basal nuclei: the head of nucleus caudatus, putamen, globus pallidus. In the claustrum degenerative changes were not observed.     

Cytoarchitectonic pattern of the hypothalamus in the turtle,Lissemys punctata granosa

Summary In the hypothalamus of the turtle, Lissemys punctata granosa, two magnocellular and 23 parvocellular neuronal complexes can be distinguished. The magnocellular complexes include the nucleus supraopticus and the nucleus paraventricularis; paraventricular neurons are partly arranged in rows parallel to the third ventricle. Most infundibular parvocellular nuclei display neurons disposed in rows parallel to the ventricular surface. In the preoptic region, the prominent parvocellular neuronal complexes encompass the nucleus periventricularis anterior, lateral preoptic area, the nucleus of the anterior commissure and the nucleus suprachiasmaticus. The prominent nucleus periventricularis posterior extends caudad and shows neurons arranged in vertical rows parallel to the third ventricle. Other parvocellular nuclei of the rostral hypothalamus are composed of clustered subunits. The nucleus arcuatus is a fairly large nuclear entity extending from the level marked dorsally by the nucleus paraventricularis to the area occupied by the nucleus of the paraventricular organ. A well-developed ventromedial nucleus is located ventrolateral to the paraventricular organ. The prominent paraventricular organ consists of tightly arranged neurons, some of which possess apical projections into the third ventricle; it is surrounded by the nucleus of the paraventricular organ. Nucleus hypothalamicus medialis et lateralis, nucleus hypothalamicus posterior and the nuclei recessus infundibuli are further nuclear units of the tuberal region. The caudal end of the hypothalamus is marked by the nucleus mamillaris; its neurons are scattered among the fibers of the retroinfundibular commissure. The median eminence is well developed and shows a large medial and two lateral protrusions into the infundibular recess.     

Head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha): a combination of transmission electron microscopical and immunocytochemical techniques

The anterior and posterior head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha) were investigated by transmission electron microscopy (TEM). In addition, whole individuals were labeled with phalloidin to mark F-actin and with anti-alpha-tubulin antibodies to mark microtubuli and studied with confocal laser scanning microscopy. Immunocytochemistry reveals that the large number of ciliary processes in the anterior head sensory organ contain F-actin; no signal could be detected for alpha-tubulin. Labeling with anti-alpha-tubulin antibodies revealed that the anterior and posterior head sensory organs are innervated by a common stem of nerves from the lateral nerve cords just anterior of the dorsal brain commissure. TEM studies showed that the anterior head sensory organ is composed of one sheath cell and one sensory cell with a single branching cilium that possesses a basal inflated part and regularly arranged ciliary processes. Each ciliary process contains one central microtubule. The posterior head sensory organ consists of at least one pigmented sheath cell and several probably monociliary sensory cells. Each cilium branches into irregularly arranged ciliary processes. These characters are assumed to belong to the ground pattern of the Gastrotricha.     

Organization of the connections of the putamen with the cerebral cortex and hypothalamus]

Connection between the putamen, the brain cortex and the hypothalamus, as well as the role of the former in different aspects of purposive behaviour have been studied in a complex morpho-physiological investigation. In 12 cats, after developing a symmetrical active-defensive conditioned reflex, unilateral electrolysis of the putamen has been performed and the number of conditioned-reflexive reactions have been counted before and after coagulation. The brains have been treated after Nauta--Gygax, Fink--Heimer with additional staining after Kawamura--Niimi. Monosynaptic connections of the putamen with frontal, precentral, postcentral, orbital, parietal cortical areas have been revealed; direct pathways from the putamen to the infundibulum of the grey tuber, to the posterior and lateral hypothalamic nucleus have been demonstrated; participation of the putamen in the formation of active-defensive conditioned reflexes has been stated, as well as in emotional behaviour with a preferable use either the right or the left foreleg.     

Effect of glutaraldehyde fixation on the localization of various oxidative and hydrolytic enzymes in the brain of rhesus monkey, Macaca mulatta

Synopsis Histochemical investigations have been made on the localization of certain oxidative and hydrolytic enzymes in the different areas of rhesus monkey brain using unfixed, freshfrozen tissue and 3% glutaraldehyde-fixed material. After glutaraldehyde fixation, the oxidative enzymes lose most of their activity normally demonstrable in the fresh-frozen section. The hydrolytic enzymes are somewhat resistant to fixation but also lose about half of the enzyme activity observed after no fixing procedure. The glycogen is better preserved in the glutaraldehyde-fixed material compared to fresh-frozen or even formaldehyde-fixed tissue. The significance of these observations is discussed in relation to glutaraldehyde as a fixative of choice in electron histochemistry.List of abbreviations used in the Figures ALH area lateralis hypothalami - APH area posterior hypothalami - AS aquaeductus Sylvii - ATN anterior thalamic nuclei - BC brachium conjunctivum - CC corpus callosum - CD nucleus caudatus - CI capsula interna - CIS cortex insularis - CM centrum medianum thalami - COR corona radiata - CP commissura posterior - CSR colliculus superior - EM eminentia medialis - F fornix - GC substantia grisea centralis - GLM corpus geniculatum laterale, magnocellular part - GLP corpus geniculatum laterale, parvocellular part - GP globus pallidus - LD nucleus lateralis dorsalis thalami - LME lamina medullaris externa thalami - LMI lamina medullaris interna thalami - LP nucleus lateralis posterior thalami - MD nucleus medialis dorsalis thalami - ML nucleus lateralis corpus mammillaris - MM nucleus medialis corpus mammillaris - NC nucleus centralis thalami - NCI nucleus colliculi inferioris - NLL nucleus lemnisci lateralis - NR nucleus ruber - NSTH nucleus subthalamicus - N III nervus oculomotorius - PC nucleus paracentralis thalami - PCR pedunculus cerebri - PUT Putamen - PV nucleus paraventricularis hypothalami - R nucleus reticularis thalami - RU nucleus reuniens thalami - SM stria medullaris thalami - SMH nucleus supramammillaris hypothalami - SMT nucleus submedius thalami - SN substantia nigra - TO tractus opticus - VL nucleus ventralis lateralis thalami - VP nucleus ventralis posterior thalami - ZI zona incerta - II ventriculus lateralis - III ventriculus tertius