A common system of sparsely-branched projection (reticular) NADPH-diaphorase neurons in formations of densely-branched cells in the human forebrain.

Morphometric studies of human forebrain formations composed of densely branched cells - the entorhinal cortex, the basolateral amygdala, the nucleus accumbens, the striatum, and the dorsal thalamus - were performed using nine parameters, with statistical analysis of the resulting data; measurements addressed the major projection-type densely branched and sparsely branched reticular neurons (scattered reticular and marginal reticular cells of the dorsal thalamus) stained by the Golgi method and with NADPH-diaphorase. Scattered reticular cells in the various formations showed no differences in any of the nine measures, while there were significant differences (in 5-7 measures, apart from one comparison, where there were differences in two measures) in their major projection-type densely branched cells. Scattered reticular and main projection-type densely branched neurons in each formation differed in terms of 7-9 measures. In endbrain formations, scattered reticular neurons contained NADPH-diaphorase; in the dorsal thalamus, only intermediate marginal reticular neurons were NADPH-diaphorase-positive. Thus, these human formations contained a common system of ancient integrative NADPH-diaphorase-containing reticular cells. Our results, along with published data, show these to be projection-type cells with projections to layers V and VI of the neocortex, which suggests that they have modulatory influences on its descending systems.

Two types of projection neurons in human striatum: peculiarities of their somatodendritic structure in ventral and dorsal striatum.

The somatodendritic structure of projection neurons was morphometrically examined in the nucleus accumbens of human brain. In contrast to reticular neurons, spiny neurons of the nucleus accumbens and dorsal striatum have different somatodendritic structure. In both parts of the striatum, reticular neurons were NADPH-diaphorase-positive.

[Common system of sparsely branched projection (reticular) NADPH-diaphorase neurons in the human forebrain formations built from densely branched cells].

Cell morphometry with statistical analysis (using 9 parameters) of densely branched projection and sparsely branched reticular neurons was performed in the human forebrain formations built from densely branched projection neurons (the entorhinal cortex, striatum, nucleus accumbens basolateral amygdala, and dorsal thalamus). The reticular neurons included scattered reticular neurons and marginal reticular neurons of the dorsal thalamus. Golgi method and staining for NADPH-diaphorase were used. The scattered reticular neurons of different formations under study did not differ in any of the 9 parameters, whereas they significantly differed from the main projection neurons in 5 to 7 parameters (except one comparison with the difference in 2 parameters). Within the same formation, the scattered reticular and main projection densely branched neurons differed in 7 to 9 parameters. The endbrain scattered reticular neurons expressed NADPH-diaphorase, while in the dorsal thalamus only the medium marginal reticular neurons were NADPH-diaphorase-positive. Thus, a common system of ancient integrative reticular neurons expressing NADPH-diaphorase exists in the examined human forebrain formations. The evidence obtained by us and the literature data point to the projection nature of the scattered reticular neurons (to the V and VI neocortical layers), which suggests their modulatory influence on descending neocortical pathways.

Neurons of the basal ganglia of the human brain (striatum and basolateral amygdala) expressing the enzyme NADPH-d.

Types of NADPH-d+ neurons (Vincent et al., 1983) were identified in the striatum and basolateral nuclei of the amygdala; striocortical neurons were detected in the striatum using the DiI marker (Belichenko and Dahlström, 1995). NADPH-d+ cells were numerous. Staining of these cells and all their processes, along with our previous studies of the neurons in these formations in the human brain using the Golgi method, allowed us to identify their shapes and identify them as sparsely or extensively branched cells. The main efferent neurons of the striatum and basolateral amygdala (extensively branched medium spiny cells and bushy spiny cells respectively) and their extensively branched interneurons did not contain NADPH-d. Efferent NADPH-d+ neurons included reticular, sparsely branched cells with long dendrites, which were the most numerous cells in both formations, as well as occasional large multipolar branched neurons; the striatum also contained numerous sparsely branched short-dendrite cells (a neuron type most represented in the brainstem and especially the reticular formation). Projections of reticular cells from the striatum to the cortex were demonstrated. NADPH-d+ interneurons were sparsely branched: in the striatum, these were slender, long-dendrite, bipolar cells (numerous), ordinary bipolar cells, twisted and large dendrite-poor cells; the amygdala contained the same bipolar cells along with radial neurons. Thus, NADPH-d+ neurons in these formations were more ancient, i.e., structurally less complex, cell types.

[Neurons of the human basal ganglia (striatum and basolateral amygdala) expressing the enzyme NADPH-d]. / Neirony bazal'nykh gangliev mozga cheloveka (striatuma i bazolateral'noi mindaliny), ékspressiruiushchie ferment NADPH-d.

In human striatum and basolateral amygdala NADPH-d+ neurons were revealed (after Vincent et al., 1983); and in striatum strio-cortical neurons were also revealed using DiI marker (after Dahtstrom and Belichenko, 1995). The NADPH-d+ neurons were numerous in both formations. Staining of NADPH-d+ neurons with their processes, and our previous study of striatal and amygdalar human neurons by Golgi method made it possible to identify the species of neurons with their assessment as sparsely or densely branched. The main efferent neurons of striatum and basolateral amygdala (densely branched medium spiny and bushy spiny, respectively) and their densely branched interneurons were not marked. Efferent NADPH-d+ neurons included the most numerous ones in both formations. A projection of reticular striatal neurons to cortex was also shown. The NADPH-d+ interneurons belonged to sparsely branched forms. In striatum they included slender-dendritic and long-dendritic bipolars (numerous), ordinary bipolars, twisted and large poor-dendritic cells; in amygdala--the same bipolars and radial cells. Thus, the NADPH-d positive cells in the formations under study were represented by more "ancient" or less structurally complex cell forms.

Morphological study of the entorhinal cortex, hippocampal formation, and basal ganglia in Rett syndrome patients.

Entorhinal cortex (EC), fascia dentata (FD), hippocampus (HP), and basal ganglia (BG) were studied in Rett syndrome (RS) cases and compared with control brains and an autism case. Kluver-Barrera and Golgi methods were used. In RS most of the areas of EC, HP, and FD showed severe cell hypochromia. In the EC all cells of layer II and most in layer III were in a state of total chromatolysis or were "ghost" cells, but the cells of layers V and VI were preserved and moderately hyperchromic. In FD and HP the majority of the granular cells and cells of CA3 and CA4 fields were severely hypochromic, whereas in the CA1 field most cells were normal or slightly hypercaryochromic. In BG mostly mild or moderate aberration from normal cell structure was observed: in striatum, mild hypercaryochromia of small neurons and more expressive hyperchromia of large neurons were found; and in pallidum, mild or moderate hypercaryochromia to severe hyperchromia in pallidum internum was found. Degeneration of thick myelinated fibers was evident in pallidum. Large striatal and pallidal neurons showed signs of constructive changes in Golgi slices. These data allow the determination of the cause of the main symptoms of RS. The motor disorders, including specific stereotyped movements, could be related to the enhanced activity of BG cells due to their deafferentation from the side of the neocortex and to supposed hyperactivity of the EC-striatal pathway; the mental retardation and epileptic seizures could be due to FD-HP involvement.

[The cellular structure of the islands of Calleja Magna in the brain of carnivores]. / Struktura kletok bol'shikh ostrovkov Kalekha mozga khishchnykh.

Complex study of the structure of islands of Calleja in carnivore brain (cat and dog) was conducted. Using Nissl and Golgi methods, HRP axonal transport and electron microscopy the islands were found to be composed of cells of 3 types varying in size, shape, dendrite spatial distribution and ultrastructure. The majority of cell population in the islands is formed by small granular cells with scarce medium-sized, mitral-like and larger cells among them. The administration of retrograde marker into posterolateral hypothalamus provided the evidence for the presence of cells in the islands of Calleja projecting to this area. These were found to be mitral-like cells. Other cells did not exhibit staining. The resemblance between mitral-like and granular cells of the large islands of Calleja with mitral-like and granular cells of olfactory bulb, respectively, supports our assumption that these islands compose the central sensory nucleus (presumably of the sensory terminal nerve).

Large neostriatal neurons in humans and their possible role in neuronal networks.

The Golgi method was used to study the structure of large neostriatal neurons in adult humans. Four types of large interneurons were found (spider cells, hairy cells, asymmetric fan cells, and giant stretched cells), along with two types of large projection cells (large reticular cells with spines and giant reticular cells with smooth dendrites). The structural features and possible mediators of these cells are discussed, along with their roles in neostriatal neuronal networks and in the development of pathological symptoms in chorea and progressive supranuclear paralysis.

[The structure and connections of the basal ganglia. The striatum]. / Struktura i sviazi bazal'nykh gangliev. Striatum.

On the base of personal studies there were reviewed contemporary data about the internal organization of mammal striatum (n. caudatus, putamen): of their histological and histochemical differentiation, neuronal content, mediators of their neurons, and of the intrinsic and extrinsic connections of these structural elements: there were put forward some hypothesis about functional specificity of these elements and about the arrangement of striatal neuronal network.

[Large neurons of the human neostriatum and their role in the neural network]. / Krupnye neirony neostriatuma cheloveka i ikh vozmozhnaia rol' v ego neironnykh setiakh.

4 types of large interneurons (spidery, hairy, fanlike, and giant stretched) and 2 types of large projection cells, were found in the adult human neostriatum. Their structural specifics, transmitters and role in the neostriatum network under normal conditions and in chorea and progressive supranuclear palsy, are discussed.

[The internal structural differentiation of the putamen in carnivores (the dog) and man]. / Vnutrenniaia strukturnaia differentsirovka skorlupy mozga khishchnykh (sobaka) i cheloveka.

The putamen tissue was found to have a complicated pattern of different structural fractions in its different parts. These seem to be special morphofunctional modules of the putamen comparable with cortical column fractions.

[The giant multipolar neurons of the reticular formation in the rat brain stem after a 14-day space flight]. / Izuchenie gigantskikh mul'tipoliarnykh neironov retikuliarnoi formatsii stvola mozga krys posle 14-sutochnogo kosmicheskogo poleta.

The effect of a 2-week space mission on the geometry parameters of giant multipolar neurons of the brain stem reticular formation in the rats flown on board Cosmos-1887 and -2044 are studied. Compensation for a deficiency of vestibular informations from the trigeminal nerve system at the cost of an decreased length of the dendrites oriented toward primary sensory nucleus and from the vestibular system through an increase in the length of the vestibular sensory nuclei-oriented dendrites is discussed.

Peculiarities of the polypeptide composition of the morphofunctionally different neurons of the rat brain.

The present study was aimed to identify peculiarities of the polypeptide composition in three morphofunctionally different classes of neurons of the rat brainstem: giant multipolar neurons of n. reticularis gigantocellularis, relay sensory neurons of lateral geniculate body and pyramidal neurons of the pyramidal layer of the CA3 - CA4 fields of hippocampus. The method of free hand dissection of neurons and sodium dodecyl sulfate (SDS) slab gel microelectrophoresis in our modifications were used. Polypeptide peculiarities for each class of investigated neurons have been found. Most of these polypeptides belong to the low molecular weight range (8.8-24.3 KD) of the polypeptide spectra and only some of them to the high one (64.6-75.3 KD).

[The effects of the electrical microstimulation of the areas of the location of different cell types in the caudate nucleus]. / Effekty élektricheskoi mikrostimuliatsii zon raspolozheniia kletok razlichnykh tipov v khvostatom iadre.

Effects of electrostimulation of the caudate nucleus in cats were studied in chronic experiments. Position of electrolytic lesions resulting from stimulation was examined histologically with respect to the surrounding cell type. Stimulation of the caudate nucleus zones with cells responding to sensory stimuli induced cat's movement and corresponding lesions were situated around striosomes among large cells with long axons. Stimulation of "silent" zones (where we failed to record any neuronal activity) did not modify cat's behaviour, corresponding lesions were found inside striosomes in clusters of small and medium-size cells. Results obtained from this study confirm the previous conclusion that neurons which activity was recorded extracellularly in the caudate nucleus belong to large long-axon cells.

[Morphometry of giant multipolar neurons of the brain stem reticular formation in rats on board the Kosmos-1667 biosatellite]. / Morfometriia gigantskikh mul'tipoliarnykh neironov retikuliarnoi formatsii stvola mozga krys, nakhodivshikhsia na biosputnike "Kosmos-1667".

Giant multipolar neurons of nucleus reticularis gigantocellularis of rats which had been kept on board the biosatellite "Kosmos-1667" were morphometrically studied. There was a trend towards the increase in the cellular surface, the maximum diameter of dendritic field, the volume of the whole dendritic territory in the test group ad in the control experimental group kept on the earth. A reliable decrease in dendritic mass oriented to nucleus vestibularis and an increase in dendritic mass oriented to the midline were also found in test group, as compared to 3 control groups. Our data were discussed in the light of nervous tissue plasticity in adult mammals.

[Various principles of the organization of preterminal and terminal branches of afferent conductors in neuropil of the snail dorsal ganglia]. / Nekotorye printsipy organizatsii preterminal'nykh i terminal'nykh razvetlenii afferentnykh provodnikov v neropile dorsal'nykh gangliev vinogradnoi ulitki.

Character of ramifications in the preterminal and terminal axonal parts in the neuropil of the dorsal ganglia have been studied in 16 edible snails (Halix pomatia). The nervous tissue is impregnated with silver nitrate after Golgifast method. Serial sections are made in two projections: horizontal and vertical. The analysis of peculiarities of the spatial distribution of the afferent fibers (AF) demonstrates their several forms that are united into the following types: dominant, probable and transitional. Comparison of the edible snail AF with those in the higher vertebrata makes it possible to conclude that the character of ramification of their preterminal and terminal parts and principle of organizational connections of the AF with the postsynaptical structures are principally similar.