Bands In Nuclei Research Articles

Central cholinergic pathways in the rat: An overview based on an alternative nomenclature (Ch1–Ch6)

Monoclonal antibodies to choline acetyltransferase and a histochemical method for the concurrent demonstration of acetylcholinesterase and horseradish peroxidase were used to investigate the organization of ascending cholinergic pathways in the central nervous system of the rat. The cortical mantle, the amygdaloid complex, the hippocampal formation, the olfactory bulb and the thalamic nuclei receive their cholinergic innervation principally, from cholinergic projection neurons of the basal forebrain and upper brainstem. On the basis of connectivity patterns, we subdivided these cholinergic neurons into six major sectors. The Chl and Ch2 sectors are contained within the medial septal nucleus and the vertical limb nucleus of the diagonal band, respectively. They provide the major cholinergic projections of the hippocampus. The Ch3 sector is contained mostly within the lateral portion of the horizontal limb nucleus of the diagonal band and provides the major cholinergic innervation to the olfactory bulb. The Ch4 sector includes cholinergic neurons in the nucleus basalis, and also within parts of the diagonal band nuclei. Neurons of the Ch4 sector provide the major cholinergic innervation of the cortical mantle and the amygdala. The Ch5–Ch6 sectors are contained mostly within the pedunculopontine nucleus of the pontomesencephalic reticular formation (Ch5) and within the laterodorsal tegmental gray of the periventricular area (Ch6). These sectors provide the major cholinergic innervation of the thalamus. The Ch5–Ch6 neurons also provide a minor component of the corticopetal cholinergic innervation. These central cholinergic pathways have been implicated in a variety of behaviors and especially in memory function. It appears that the age-related changes of memory function as well as some of the behavioral disturbances seen in the dementia of Alzheimer's Disease may be related to pathological alterations along central cholinergic pathways.

Origin of cingulate cortex cholinergic innervation in the rat

The relative contribution of the n. diagonal band and thalamic nuclei to the cholinergic innervation of the cingulate cortex was examined. Lesions were placed in the n. diagonal band, anterior thalamus, and medial thalamus of rats, and changes in choline acetyltransferase in discrete regions of the cingulate cortex were determined. The n. diagonal band lesion produced a large decrease in choline acetyltransferase activity while the thalamic lesions produced no significant change in activity.

Sex differences in cholinergic enzymes of diagonal band nuclei in the rat preoptic area.

Activities of choline acetylase (CAT), synthetic enzyme for acetylcholine, and acetylcholine esterase (AChE), degradative enzyme for acetylcholine, were measured in preoptic nuclei of gonadectomized, estradiol-treated male and female rats. Estradiol-dependent enzymatic changes were localized within discrete POA nuclei and both the location and direction of the changes were dependent on the sex of the rat. Estradiol administration increased CAT and AChE activity in the nucleus of the horizontal limb of the diagonal band in ovariectomized (OVX) females but not castrate (CAS) males and decreased CAT activity in the nucleus of the vertical limb of the diagonal band in CAS males but not OVX females. Activity of AChE was increased by estradiol administration in the bed nucleus of the stria terminalis in OVX females but not in CAS males. Activity of cholinergic enzymes remained higher in the nucleus of the horizontal limb of the diagonal band of females than males after long-term gonadectomy. Estradiol-dependent increased CAT activity in the nucleus of the horizontal limb of the diagonal bands of OVX females was partially blocked by administration of the protein synthesis inhibitor, anisomycin, and was not affected by acute progesterone administration. These results extend previous morphological demonstrations of dimorphisms between the sexes within the preoptic area to include neurochemical parameters of neuronal function.

Rules governing the composition of revolving clusters in quasiband and prolate-deformation states of atomic nuclei

A set of rules, involving the magic and semimagic values of neutron and proton numbers and the proton/neutron ratio, is formulated for the composition of the revolving clusters producing the values of the moment of inertia given by the differences in energy of the adjacent levels in quasibands and bands of nuclei. The cluster compositions assigned with use of these rules to isotopes of Kr, Sr, Zr, Mo, and the actinon nuclei and to successive levels of the ground-state band of (158)Er lead to reasonable values of the radius of revolution (the distance from the center of the nonrevolving sphere to the center of the cluster). These values correspond to a spheron diameter of about 3.20 fm.

An HRP study of the connections of the subfornical organ of the rat.

The connections of the subfornical organ (SFO) were investigated by using the HRP technique. Injections into the SFO labeled neurons in the medial septum, but not in lateral septum nor in the diagonal band nucleus. Labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal preoptic region near the anterior commissure, and diffusely throughout the medial preoptic and anterior hypothalamic areas. Fibers were followed from the ventral stalk of the SFO. Precommissural fibers enter the median preoptic nucleus where many of them appear to terminate. Others continue on to the medial septum, the OVLT, the supraoptic nucleus, and suprachiasmatic nucleus. HRP injections into the median preoptic nucleus labeled many neurons in the SFO. Postcommissural fibers reach the hypothalamus by descending along the walls of the ventricle in the subependymal space, by traveling in the columns of the fornix and the medial corticohypothalamic tract, or by passing through the paraventricular nucleus of the thalamus. Some postcommissural fibers turn rostrally and enter the median preoptic nucleus while others join precommissural fibers bound for the supraoptic nucleus. More caudally directed fibers appear to innervate the paraventricular nucleus of the hypothalamus and the medial preoptic and anterior hypothalamic areas. HRP injections into the paraventricular nucleus of the hypothalamus labeled neurons in the SFO. These findings corroborate and extend previous work in describing neural connections between two brain regions that are important for fluid balance.

On the interaction of the s-band with the ground state and gamma band in nuclei around mass 80

A comparison of experimental data on high-spin states in 80Kr, 82Sr, 81Kr and 81Rb with cranked shell model calculations reveals first evidence for the predicted oscillations of the interaction strength between the ground state band and the g 9 2 - proton s-band. Similar oscillations of the interaction strength between the gamma and s-band are suggested.

Study of high-spin states in nuclei within the framework of a single-particle model

Starting from the cranking model and applying the Hartree-Fock-Bogolubov theory with approximate projection of the particle number, one may give a satisfactory description of many properties of the rotational bands in nuclei. Calculations within the framework of this model show that the anomalies at high-spin states are caused by two effects: the Coriolis antipairing which reduces the energy gap with increasing angular momentum, on the one hand, and the alignment of the neutrons of positive parity along the axis of rotation, on the other hand. Moreover, the results show that the speed with which the alignment occurs has an important effect on the appearance of anomalies at high angular momenta.

An HRP study on the distribution of all nuclei innervating the supraoptic nucleus in the rat brain

Detailed histochemical studies have been performed on the distribution of the nuclei innervating the supraoptic nucleus (SO) in the whole brain after horseradish peroxidase (HRP) injections through fine glass micropipettes (2 to 8 micrograms ) into the SO of 39 Wistar strain rats. The chromatogenic reaction was carried out according to the Mesulam's (1976) No. 8 procedure. Successful HRP injections resulted in labeling in various regions of the brain. The following conclusions were drawn from the analysis of these successful cases. All the nuclei of the subthalamus and posthypothalamus innervate the SO whereas only a few neurons of the hypothalamic arcuate and ventromedial nuclei probably send axons to it. The afferent monoaminergic fibers arise largely from the B7 and B8, and to a certain extent from the A6 and A10 cell groups. The septum, diagonal band nucleus and amygdala project directly to the SO while the olfactory tubercle and pyriform cortex may not. The mesencephalic central gray has a high possibility to project directly to it. The possibility that the hippocampus sends axons to the SO remains to be fully proven. A few small multipolar cells clearly revealed by the test in the SO should be non-secretory intercalated neurons.

Topographic organization of the projection from the forebrain subcortical areas to the hippocampal formation of the rat

Using the technique of iontophoretic microinjection of horseradish peroxidase, the present study disclosed the complexity and high degree of the topographic organization in the forebrain subcortical afferents to the different regions of rat hippocampus, e.g. diagonal band, posterior (PH), dorsomedial and rostral lateral hypothalamic nuclei chiefly project to the rostrodorsal part (DRA) and caudal gyrus dentatus including CA3, the supramammillary area predominantly to the rostroventral area (VRA), the area lateral to PH to the DRA and VRA, substantia innominata and some thalamic nuclei (n. reuniens, n. lateralis thalami, n. anterior ventralis thalami and n. lateralis thalami pars posterior) to the dorsal subiculum, respectively.

Biochemical evidence for glutamate as a transmitter in hippocampal efferents to the basal forebrain and hypothalamus in the rat brain

The effects of bilateral transection of the fornix bundle on the high affinity uptake of glutamate and on the amino acid content in several nuclei of rat forebrain and hypothalamus were studied in order to investigate the possible role of glutamate as a transmitter of these fibres. This lesion decreased the high affinity uptake of l-glutamate by 60–70% in the mammillary body and lateral septum, and by 40–50% in the anterior diagonal band nucleus, the bed nucleus of the stria terminalis, the mediobasal hypothalamus and the nucleus accumbens. The content of endogenous glutamate in samples dissected from freeze-dried tissue also decreased significantly in these regions. Endogenous aspartate was slightly decreased in the anterior diagonal band nucleus and the mammillary body, but unchanged in the other regions. No significant changes were seen in the levels of serine, γ-aminobutyric acid, glutamine and taurine, except for an increase in glutamine and taurine in the bed nucleus of the stria terminalis. The high affinity uptake of γ-aminobutyric acid, tested in the bed nucleus of the stria terminalis, the mediobasal hypothalamus and the mammillary body, was unchanged after the lesion. The results indicate that allocortical efferents innervating subcortical nuclei through the fornix might use glutamate as a transmitter. The study further supports the concept that glutamate plays an important role as transmitter of several different corticofugal fibre systems in mammalian brain.

Physiology of nerve growth factor.

Physiology of nerve growth factor.

The development of the septal region in the rat. I. Neurogenesis examined with 3H-thymidine autoradiography.

Neurogenesis in the rat septal region was examined with 3H-thymidine autoradiography. The rats in the prenatal groups were the offspring of pregnant females given two injections of 3H-thymidine on consecutive days in an overlapping series: embryonic day (E) 13 + E14, E14 + E15,. . . E21 + E22. The rats in the postnatal groups were injected in a nonoverlapping series: the day of birth and postnatal day (P) 1, P2 + P3, P3 + P4. On 60 days of age, the percentage of labelled cells and the proportion of cells added during each day of formation were determined at several anatomical levels within the midline nuclear group (nucleus of the diagonal band, medial and triangular septal nuclei), the lateral septal nucleus, and the ventrolateral nuclear group (nucleus accumbens, bed nuclei of the stria terminalis and the anterior commissure). The neurons within each nuclear group form in significantly different waves, those of the midline group forming between E13-E17, the lateral septal nucleus between E15-E19, the bed nuclei of the stria terminalis and anterior commissure between E14-E18, the nucleus accumbens between E17-P2. All nuclei and nuclear groups show characteristic gradients of formation. Both the midline nuclear group and the bed nucleus of the stria terminalis (including the commissural bed nucleus) have their earliest forming neurons lying near the crossing of the anterior commissure; younger nuerons are located both rostrally and caudally with the youngest neurons lying in the most rostral extension of the diagonal band nucleus and the strial bed nucleus. The lateral septal nucleus forms along a strong mediolateral gradient throughout its length after neurogenesis is almost complete in the midline nuclear group. Throughout the length of the nucleus accumbens, the oldest neurons are located ventrally while progressively younger cells are found dorsally beneath the inferior horn of the lateral ventricle.

The development of the septal region in the rat. II. Morphogenesis in normal and x-irradiated embryos.

Morphogenesis of the septal region was examined in normal rat embryos from embryonic day (E) 10 to E22. The greater part of the septal region is postulated to form from two separate anlagen which can be clearly distinguished in the telencephalon by E13 and E14. One lies in the anterior ventromedial wall and presumably forms the nucleus of the diagonal band, medial, lateral, and triangular septal nuclei. The other lies in the posterior ventrolateral ridge and presumably forms the bed nuclei of the stria terminalis and the anterior commissure. On E15, the early differentiating cells in these anlagen fuse in the same region where the anterior commissure will cross on E17. With later embryonic development, differentiating cells of the strial bed nucleus accumulate rostral and caudal to the fused area. The same pattern is found in the medial and triangular septal nuclei and in the nucleus of the diagonal band. The differentiating cells of the lateral septal nucleus accumulate dorsal and lateral to medial and triangular septal nuclei. On E16 and E17, a prominent subependymal zone develops in the anterior septal region and presumably gives rise to the nucleus accumbens. A quantitative analysis was made of three cell zones (neuroepithelium, subependymal zone, differentiating cell zone) at coronal levels through the developing nucleus accumbens and the nucleus of the diagonal band (anterior level) and the medial and lateral septal nuclei (middle and posterior levels). At all levels, the area of the neuroepithelium continually declines, that of the differentiating cell zone continually increases, and that of the subependymal zone shows a rise and decline. On a proportional basis, both the neuroepithelium and subependymal zone occupy significantly more area anteriorly than posteriorly, while the differentiating cell zone shows the reverse gradient. To accurately locate regions of primitive mitotic and migratory cells within the zones at each level, the number of cells surviving a single exposure to 200 R X-rays in embryonic brains (E15-E22) were compared with controls. Each zone responded differently to X-ray insult. The radiosensitivity of the neuroepithelium decreases significantly after E19; the subependymal zone is highly radiosensitive throughout; the differentiating cell zone is radioresistant throughout. The significance of these findings is discussed in the light of the autoradiographic determination of the time of formation of septal neurons (Bayer, '79).

Afferent connections of the entorhinal area in the rat as demonstrated by retrograde cell-labeling with horseradish peroxidase

The entorhinal cortex (EC) of the rat has been divided into medial (MEA) and lateral (LEA) subdivisions. In order to analyze its afferent connections, small deposits of horseradish peroxidase (HRP) were placed at various loci within EC. The patterns of retrograde cell-labeling charted in 18 such cases suggested that EC is projected upon by several allocortical and subcortical structures and that there are differences in the afferent connections of the two subdivisions. Thus, although HRP injection of either division of EC led to cell-labeling in the hippocampal formation, most in ammonic field CA1 and the subiculum, several cells of the presubiculum were preferentially labeled by injection of MEA. Injections of LEA, but not those in MEA, resulted in substantial cell-labeling in the anterior piriform cortex of both hemispheres. Regardless of the location of its injection site within EC, the enzyme labeled cells in the diagonal band nucleus of Broca, amygdala and claustrum. The pattern of cell-labeling in the diagonal band nucleus extended into the ventrolaterally contiguous nucleus basalis after injection of LEA and into the dorsally contiguous medial septal nucleus after injection of MEA Whereas HRP deposits in either division of EC resulted in cell-labeling in the cortical and medial nuclei of the amygdala, only those deposits which involved LEA led to cell-labeling in the posterior part of the lateral nucleus. In the thalamus, labeled cells were found in the rostral part of the paratenial, periventricular and reuniens nuclei. Finally, at midbrain levels, numerous labeled cells appeared in the dorsal raphe nucleus, a few in the median raphe and locus coeruleus, and, only after rostral EC injection, in the ventral tegmental area.

Theory of coupled rotational bands in nuclei: (I). General

An RPA type approach to nuclear rotation and its coupling to other modes is proposed, giving both energies and transition rates in deformed nuclei. It is based on a general expansion of any multipole operator, in terms of earlier introduced elementary transition operators, acting in and between nuclear rotational bands. The expansion is formally obtained by using symmetry properties only. The matrix element of any expansion term is calculated from the algebraic properties of the transition operators. Applied to the Hamiltonian it gives a phenomenological model, accounting for vibrations and rotation with coupling between these modes, together with the prescription for evaluation of the model parameters. Applied to a multipole transition inducing field, it leads to a model-independent derivation of the spin ( I)-dependent corrections to adiabatic unified model transition rates. A microscopic procedure for calculating the model-dependent expansion coefficients is proposed. The latter are expressed in terms of the elementary transition operators, or in terms of an extended density matrix involving these operators, giving their quasiparticle structure. The procedure is based on a generalized equations-of-motion method for the density matrix. The method is illustrated by the example of coupled ground-state (g), beta (β)-state and gamma (γ)-state rotational bands in even-even nuclei. Results for E2 non-adiabatic transition rate corrections inside the g-band and for transitions from the γ- and β-bands to the g-band are obtained. This example is to be developed in the following paper towards numerical applications and an extension of the description to high-spin states.

Theory of coupled rotational bands in nuclei: (II). Application to even-even nuclei

The method developed in the preceding paper is applied to study the basic parameters of the states belonging to the ground, β- and γ-rotational bands in even-even deformed nuclei. The parameters of the model Hamiltonian and the expansion coefficients of the physical operators are calculated within a microscopic model, including pairing and quadrupole-quadrupole interactions in an average field of the Woods-Saxon type. One obtains the energies of the states and the non-adiabatic corrections to the different multipole moments in the charge and density distributions of nuclei, and electromagnetic transition probabilities. The agreement of the theoretical results with the known experimental data is generally good. Some conclusions are drawn concerning the deformability of the rotating nuclei in the region of angular momenta critical for the exisience of pairing correlations.

The topographic organization of hypothalamic and brain stem projections to the hippocampus

Direct projections primarily ipsilateral to hippocampus from medial septal, diagonal band, supramammillary, submammillothalamic, locus coeruleus, and dorsal and medianus raphe nuclei were demonstrated. The locus coeruleus projects primarily through the cingulum and fornix superior to the dorsal posterior hippocampus, with its terminal fields in the stratum lacunosum moleculare of the subiculum and areas CA 1-CA 2 of the dorsal posterior hippocampus. LC projections to the granular layer of the dentate hilus were not found. Raphe nuclei project through the cingulum, fornix superior, and primarily the fimbria, to the dorsal and ventral posterior hippocampus, with their terminal fields in the stratum lacunosum moleculare of the dorsal posterior subicular region, stratum radiatum of CA 1-CA 3 in the dorsal hippocampus, and the stratum polymorph of the dentate gyrus, primarily in its superficial part. Raphe projections to the anterior hippocampal rudiment were found. However, no projection was found to the subiculum of the ventral posterior hippocampus, nor to stratum oriens. Hypothalamic nuclei project through the fornix superior and the fimbria, mainly to the dorsal posterior hippocampus with abundant terminal fibers in the depth of the dentate hilus. Smaller cells in these hypothalamic nuclei appear projecting to the ventral hippocampus. The number of neurons in the entorhinal area, the diagonal band, and the hypothalamic nuclei projecting to the hippocampus suggests these groups as the main sources of the extrinsic hippocampal afferents. In addition, they may also serve as relay stations for inputs from more caudal nuclei, and the topographic organization of their terminal fields as described herein may have important functional implications.

Dopamine and noradrenaline neurons projecting to the septal area in the rat.

The organisation of the catecholamine innervation of the rat spetal area was investigated by means of the glyoxylic acid fluorescence method in combination with dopamine uptake studies, lesions and retrograde tracing of horseradish peroxidase. The following catecholamine systems to the septum could be established: 1. The Locus Coreuleus Noradrenergic System. These axons are widespread in the septum forming a moderately dense innervation in the anterior hippocampus, the medial septal nucleus, the nucleus of the diagonal band, and the interstitial nucleus of the stria terminalis, and a sparse innervation in the lateral septal nucleus and the septofimbrial nucleus. 2. The Medulla Oblongata Noradrenergic System. This system originates in the A1, A2 or A3 cell groups, the axons forming a very dense innervation in the ventral part of the interstitial nucleus of the stria terminalis, a moderately dense innervation in the nucleus of the diagonal band and lateral septal nucleus, and a sparse innervation in the medial septal nucleus, the septofimbrial nucleus and the dorsal part of the interstitial nucleus of the stria terminalis. 3. The Mesencephalic Dopaminergic System. This system originates in the medial part of the A10 cell group, the axons forming two distinct terminal patterns. In the first type, smooth axons form pericellular arrangements around non-fluorscent neurons in the lateral septal nucleus. The second type is formed by fine-varicose axons which form a dense band around the fornix in the medial part of the lateral septal nucleus. 4. The Incerto-Hypothalamic Dopaminergic System. These axons most probably originate in cell bodies of the diencephalic A11, A13 and A14 cell groups, and are found in the lateral septal nucleus at the level of the anterior commissure.

Olfactory relationships of the telencephalon and diencephalon in the rabbit. III. The ipsilateral centrifugal fibers to the olfactory bulbar and retrobulbar formations.

The axoplasmic retrograde transport of horseradish peroxidase (HRP) from axon terminals to their parent cell bodies and histochemical fluorescence microscopy have been used to study the ipsilateral centrifugal fibers to the olfactory bulbs and anterior olfactory nucleus in the rabbit. Focal injections of peroxidase were placed unilaterally into the main or accessory olfactory bulb or into the anterior olfactory nucleus. In animals with injected HRP confined within the main bulb, perikarya retrogradely labeled with the protein in the ipsilateral forebrain were observed in the anterior prepyriform cortex horizontal limb of the nucleus of the diagonal band, and far lateral preoptic and rostral lateral hypothalamic areas. Brain stem cell groups that contained HRP-positive somata include the locus coeruleus and midbrain dorsal raphe nucleus. Except for the prepyriform cortex, the basal forebrain structures with labeled perikarya correlate well with locations of cell bodies containing acetylcholinesterase and choline acetyltransferase. These somata may represent a cholinergic afferent system to the main olfactory bulb. Peroxidase-labeled cell bodies in the locus coeruleus and midbrain raphe are indicative of noradrenergic and serotonergic innervations respectively of the olfactory bulb. In rabbits in which peroxidase was injected or diffused into the accessory olfactory bulb and anterior alfactory nucleus, HRP-positive somata were identified in the prepyriform cortex bilaterally, the horizontal limb of the diagonal band nucleus, lateral hypothalamic region, nucleus of the lateral olfactory tract, corticomedial complex of the amygdala, mitral and tufted cell layers of the ipsilateral main olfactory bulb, locus coeruleus, and the midbrain raphe. Evidence for centrifugal fibers to the accessory olfactory bulb from the corticomedial complex of the amygdala, locus coeruleus, and possibly the nucleus of the lateral olfactory tract and midbrain raphe is discussed. A similar distribution of labeled perikarya in the forebrain and brain stem was seen in rats in which peroxidase injected into the main olfactory bulb had spread into the accessory bulb and anterior olfactory nucleus. Histochemical fluorescence microscopy of the main and accessory olfactory bulbs in the rabbit and rat revealed fine caliber, green fluorescent fibers and varicosities predominantly in the granule cell layer and less so among cells in the glomerular layer. In sections through the root of the main olfactory bulb, a similar fluorescence was seen in the deep half of the plexiform layer of the pars externa of the anterior alfactory nucleus. These fluorescent fibers likely represent the noradrenergic innervation of the olfactory bulbar and retrobulbar formations. A fluorescent yellow hue was observed in the glomerular layer of the main bulb and may signify a serotonergic innervation of this lamina...

Alpha-particle superfluid bands in nuclei

The systematics of α-particle separation energy is studied from the point of view of pairing-rotational structure. Two mass regions are identified where collective pairing bands can exist. The moment of these bands is compared with linear sums of (n-n) and (p-p) bands and an increase in collectivity of factor 10 is deduced.