ABSTRACT
The present experiments were designed to study the afferent connections of the oval nucleus (Ov) of the bed nuclei of the stria terminalis (BST) using fluoro-gold (FG) and WGA-HRP as retrograde tracers. After injection of FG or WGA-HRP into the Ov area of the male SpragueDawley rats, a number of retrogradely labeled neurons were observed in the piriform cortex, fundus striati, subiculum, preoptie areas, horizontal limb of the diagonal band, ventral pallidum, magnocellular preoptic area, central (Ce), medial and cortical nuclei of the amygdala. A few neurons in the midline nuclei of the thalamus. were labeled. Many labeled neurons were found in the anterior, dorsal and lateral hypothalamic areas, ventral medial, arcuate and premammillary nuclei of the hypo thalamus. In the brainstem many labeled neurons were seen in the ventral part of the midbrain central gray, dorsal raphe nucleus, pedunculopontine tegmental nucleus, ventral tegmental area, compact zone of the substantia nigra, interpeduncular nuclei, interfascicular nucleus, raphe nuclei, parabrachial nuclei, locus coeruleus, mesencephalie trigeminal nucleus, dorsal vagal complex, A_5 and A_1 cell groups.In general, the distribution patterns of the labeled neurons of both tracers were quite similar except that FG labeled neurons showed much longer processes than WGA-HRP's, and some FG labeled neurons were also found in a few contralateral structures, such as central and medial nuclei of the amygdala and the horizontal limb of the diagonal band, where no WGA-HRP labeled neurons were observed.The results of this retrograde tract-tracing study together with our previous. anterograde tract-tracing study indicate that there are reciprocal connections between the Ov and the Ce, posterior part of the lateral hypothalamus and several brainstem structures.
ABSTRACT
WGA-HRP was iontophoretically delivered into the habenular nuclei in 40 rats to observe the distribution of the retrograde labeled cells; and into the entopeduncular nucleus(EPN), lateral preoptic area(LPO), medial preoptic area(MPO), nucleus septalis fimbriatis(SF), nucleus triangularis septi(TS), nucleus tractus diagonalis (Broca)(DBN)and lateral hypothalamic area(LHA) in 12 rats to observe the distribution of the orthograde labeled fibers in the habenular nuclei. It was found that the afferents of various parts of the habenular nuclei were different.The lateral habenular nucleus mainly recieves the afferents from the EPN, LPO and LHA, and the medial habenular nucleus from the SF, TS and LHA. Furthermore, the lateral habenular nucleus can be divided into medial and lateral parts, the medial habenular nucleus can be divided into medial and lateral parts as well, their afferent connections are also different.
ABSTRACT
0.05～0.2?l of HRP (Sigma Ⅵ) were introduced into the periaqueduetal gray (PAG) of 45 rats at the superior collicular level, each brain was sectioned and processed with DAB, BDHC, O-D and TMB reactions. 29 were chosen for analysis and according to the locations of the injection center and the extent of reaction, were divided into 3 groups:1. The injection center was found in the lateral part of PAG; the reaction only involved a small area within PAG (11 rats), labeled cells were seen in PAG, tectum, reticular formation (RF) and dorsal raphe nucleus.2. The injection center was in the dorsolateral part of PAG; the reaction area extended out of PAG to the nearby RF and tectum (9 rats); labeled cells were seen in the structures mentioned in group 1 as well as in habenular nucleus (hn), parafascicular nucleus (PFN), hypothalamic nuclei (anterior, posterior, ventromedial, dorsomedial, lateral), thalamic nuclei (lateral, reticular, medial part of ventral nucleus), paraventricular gray (PVG), nucleus of the optic tract, nucleus of posterior commissure (NPC), parabigeminal nucleus (PBN), locus ceruleus, ventral nucleus of lateral geniculate body, entopeduncular nucleus.3. The injection center was in the lateral or ventrolateral part of PAG, the reaction area extended to the nearby RF, tegmentum and part of tectum (9 rats), labeled cells were seen in the structures mentioned in group 1 as well as in substantia nigra, H_1, H_2, zona inserta, HN, PFN, PVG, NPC, PBN, locus ceruleus, pretectral area and nuclei of hypothalamus. In this group 3 rats were processed with TMB reaction. Labeled cells were seen not only in the above-mentioned structures but also in the deep layers of anterior cingulate cortex (areas 23 and 24), nucleus raphe magnus, nucleus reticularis gigantocellularis, periventricular gray of 4th ventricle, dentate nucleus of cerebellum, lamina Ⅴ～Ⅶ of cervical spinal cord (the other segments were left out), preoptic and supraoptic nuclei, suprachiasmatic nucleus, anterior nucleus of mammillary body, medial nucleus of amygdaloid nucleus, spinal nucleus of nerve Ⅴ. The labelled cells were seen chiefly in the ipsilateral side. Neuronal connections also were analysed according to the disparity in labelled structures.
ABSTRACT
The afferent projections to the hippocampus were studied with HRP. Thirty three per cent solution of HRP was slowly injected into the dorsal or ventral hippocampus on its right side in 25 albino rats and HRP-labelled cells were found in the following nuclei:1. On the ipsilateral side: entorhinal cortex, medial septal nucleus, supramammillary nucleus, submammillothalamic nucleus, dorsal raphe nucleus, median raphe nucleus, locus coeruleus, diagonal band and nucleus of superior colliculus.2. On the contralateral side: areas CA_3 and CA_4 of hippocampus and locus coeruleus.
ABSTRACT
Thirteen albino rats with body weight approximately from 0.4～0.6 kg were used in the experiment. Each was injected with 0.1 ?l of 30％ HRP (Sigma Type Ⅵ) solution into one of several portions of the cingulate gyrus. Two days after the injection, the animals were sacrificed and processed with Nauta's DAB and Edward's O-D methods. The results were as follows:1. Area 25 and 32 receive the fibers from areas 3, 1, 2 and globus pallidus on the ipsilateral side, and from areas 10, and 24, caudoputamen nucleus, lateral nucleus of the hypothalamus, intercavernous nucleus of the stria terminalis on both sides. The labeled cells were also found in areas 25 and 32 on contralateral side.2. Area 24 receives fibers from area 32 and the lateral part of the dorsomedial nucleus of the thalamus on the ipsilateral side, and from area 10, the anterior olfactory nucleus, caudoputamen nucleus, and septal nucleus on both sides and from areas 4 and 24 on the contralateral side.3. Areas 23 and 29 receive the fibers from areas 24,17, and 18 on the ipsilateral side, and from areas 23,29,32,25 and rostral part of the linear nucleus on the contralateral side.The results prove that the cingulate area widely receives the afferent fibers from cortex, thalamus, hypothalamus and midbrain.
ABSTRACT
Afferent connections to the nucleus tegmenti dorsalis were studied by means of retrograde axonal transport method of horseradish peroxidase (HRP). HRP was depositted stereotaxically via three approaches: vertical, oblique through the cerebellum or oblique through the cerebrum. The serial sections were treated by 3,3'-diamino-benzidine, benzidine dihydrochloride, diaminobenzidine-cobalt dichloride or tetrame-thylbenzidine respectively.Labeled neurons were observed in following nuclei: nucleus lateralis habenulae,nucleus interpeduncularis, nucleus mammillaris lateralis, nucleus posterior hypothalami, nucleus lateralis hypothalami, substantia grisea centralis mesencephali, nucleus dorsalis raphes, nucleus tractus solitarii, nucleus prepositus hypoglossi, nucleus parafascicularis and nucleus of Darkschewitsch.Then HRP was introduced into nucleus parafascicularis or nucleus prepositus hypoglossi, labeled terminals were also observed within the nucleus tegmenti dorselis.
ABSTRACT
The afferent connections of the interpeduncular nucleus (IPN) were studied with retrograde transport method of using horseradish peroxidase (HRP).A microinjected syringe needle or microelectrophoretic pipette was inserted into the brain in the vertical, inclined through cerebellum or inclined through cerebral cortex medially.The results were as follows:Following HRP injection into the IPN, labeled neurons were found in medial habenular nuclei, lateral habenular nuclei, dorsal raphe nucleus, superior central nucleus, dorsal tegmental nucleus of Gudden, dorsolateral tegmental nucleus, ventro-lateral and lateral portions of periaqueductal grey matter, and locus coeruleus. In addition, labeled cells were also observed within caudal portion of accumbens nucleus and nucleus tractus diagonalis (Broca).Following HRP injection into the lateral, ventral (or ventrolateral) and dorsal portions of the IPN, labeled cells were found in ipslateral medial habenular nucleus,medial regions of the bilateral medial habenular nuclei, and lateral regions of the bilateral medial habenular nuclei, respectively.After injection into the rostral or caudal pole of the IPN, no labeled cells were observed in bilateral medial habenular nuclei.Following injection of HRP into the caudal pole of the IPN, labeled neurons were observed within both sides of lateral habehular nucleus, dorsolateral tegmental nucleus and ventromedial portion of dorsal tegmental nucleus.No labeled neurons were observed in the ventral (deep) tegmental nucleus,premamillary nucleus, supramamillary nucleus and parabigeminal nucleus except in the cases in which the HRP injection site extended beyond the IPN.