• Applied Microscopy
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• v.18 no.1
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• pp.35-48
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• 1988

To investigate the connections between the major limbic structures and the nucleus accumbens septi or the nucleus fundus striati, stereotaxic surgeries were performed. One group of the rats were electrically lesioned in the mamillary body, and the other group were extirpated their hippocampal formation. Careful study of both nuclei following each surgery showed the following results. 1. Nerve terminals of mamillo-accumbens tract were synapsed to the dendrite of nucleus accumbens cell, whereas the neuronal type of accumbens-mamillary tract was aspiny cell. 2. Nerve terminals of mamillo-fundus tract were synapsed to the spines of fundus striati cells. Fundus-mamillary tract cells were not confirmed. 3. Nerve terminals of hippocampo-accumbens terminals were synapsed to the dendrites and spines of nucleus accumbens cells, whereas the neuronal type of accumbens-hippocampal tract was spiny one. 4. Nerve terminals of hippocampo-fundus tract were synapsed to the spines of fundus striati cells, whereas the neuronal types of fundus-hippocampal tract was aspiny one. 5. From the results, it was concluded that both of the nucleus accumbens septi and the fundus striati have connections with the mamillary body and the hippocampus. But nucleus accumbens septi has apparently more intimate relationship with major limbic structures.

• Applied Microscopy
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• v.18 no.1
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• pp.21-34
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• 1988

Comparative study on the synaptic types of the nuclei accumbens septi and fundus striati of the chick and the rat was carried out. Basic synaptic types were established according to the size of synaptic vesicles, development of synaptic vesicles, development of synaptic thickening, kind of postsynaptic structures, etc. Comparing the synaptic types and appearance-ratio within the neuropils, the following results were obtained (see the data in the Table 1). 1. In the nucleus accumbens of the rat, the axo-spinous synapses are far less than those in the nucleus fundus striati (13.7%/68.2%). 2. In the nucleus accumbens, there found much more axo-dendritic types(II, III and V) than those appearing in the nucleus fundus striati(79.1%/27.1%). 3. In the nucleus accumbens of the chick, on the contrary to the case of the rat, more axo-spinous types(70.1%/31.4%) and less axo-dendritic types(12.3%/60.0%) were found as compared to those appearing in the nucleus fundus striati. 4. There found no large-sized synaptic vesicles in the chick nuclei accumbens septi and the fundus striati.

• Journal of Acupuncture Research
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• v.20 no.4
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• pp.24-41
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• 2003

Objective: Dopamine activity in thenucleus accumbens is an important neuropharmacological component of morphine reinforcement. In this nucleus a shell and core have been distinguished on the basis of anatomical and neurochemical criteria. Although acupuncture has been standard intervention in many detoxication programs worldwide, the central mechanism by which morphine acts to reinforce behavior remain elusive. The present in vivo microdialysis study was conducted, in freely moving rats, to detect the effects of acupuncture on extracellular dopamine release in the nucleus accumbens. Methods: Male Sprague-Dawley rats received acupuncture for 1 min after injection of morphine hydrochloride (5mg/kg, s.c.). The employed acupuncture needle points corresponded to bilateral Neiguan(PC6) on the pericardium channel, which has been used to treat mental and psychosomatic disorders. Extracellular dopamine and its metabolites were measured every 20 mins for 3 hrs following the subcutaneous morphine injection. Results: Results showed that acupuncture at PC6 significantly attenuated increases in dopamine levels induced by a single acute morphine injection in the nucleus accumbens shell and core, respectively. Conclusions: These results provided strong evidence for acupuncture-mediated reduction in morphine-induced dopamine release in the rat nucleus accumbens.

• The Korean Journal of Nuclear Medicine
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• v.36 no.5
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• pp.277-287
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• 2002

Purpose and Methods: We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum and nucleus accumbens of freely moving rats using in vivo microdialysis technique. Results: Systemic pretreatment with GTS decreased striatal DA release induced by local infusion of nicotine into the striatum. However, GTS had no effect on the resting levels of extracellular DA in the striatum. GTS also blocked nicotine-induced DA release in the nucleus accumbens. Conclusion: The results of the present study suggest that GTS acts on the DA terminals to prevent DA release induced by nicotine. This may reflect the blocking effect of GTS on behavioral hyperactivity induced by psychostimulants.

• Biomolecules & Therapeutics
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• v.10 no.1
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• pp.25-31
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• 2002

This study was carried out to identify the effect of oxidative stress on the pathogenesis of manganese intoxication. Five rats in experimental group were given with $MnCl_2$intraperitoneally for 4 weeks(4 mg/kg once daily 5 days per week) and another five rats for control group were given with normal saline. In experimental group, manganese concentrations increased significantly in nucleus accumbens by 142% (p<0.05), SOD activities increased significantly by 124%(p<0.01), and MDA concentrations increased significantly 148%(p<0.05) compared with control group. Among fatty acids, total n-6 polyunsaturated fatty acids(PU) increased significantly by 231%(p<0.05) compared with control group. Arachidonic acids(AA) increased by 224%(p<0.05), and these increase were composed mostly of n-6 polyunsaturated fatty acids(PUFA). Among n-3 PUFAs except linolenic acids, eicosapentanolc acid(EPA) decreased significantly by 38%(p 0.01) and docosahexanoic acids(DHA) decreased by 30% p<0.05) compared with control group. Our results suggest that the oxygen free radicals produced by manganese may cause compositional changes of fBtty acids in nucleus accumbens of the rat. Characteristics of fatty acids compositional changes by manganese were the decrease of EPAs and DHAs(n-3 PUFAs), and increase of AAs(n-6 PUFAs). These changes with the increase of MDA, suggest that manganese neurotokxcity is caused by lipid perokidation mediated with oxygen free radicals, especially superoxide radicals.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1149-1154
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• 2006

Repeated administration of all addictive drugs, including nicotine, can produce sensitization of extracellular dopamine levels in the nucleus accumbens and behavioral sensitization in rat, as evidenced by an enhanced locomotor response and increased dopamine release in brain to a subsequent injection of the drug. In order to investigate the effect of Zizyphus jujuba extract on repeated nicotin-induced sensitization, rats were given repeated injection of saline or nicotine (0.4 mg/kg s.c., twice a day for 7 d), followed by one challenge injection on the 4th day after the last daily injection. Systemic challenge with nicotine (0.4 mg/kg s.c.) and a direct local challenge of 3 mM a larger increase in locomotor activity and extracellular dopamine release in the nucleus accumbens in nicotine-pretreated rats than in saline-pretreated rats, respectively. Zizyphus jujuba extract significantly decreases locomotor activitiy and dopamine release in the nucleus accumbens induced by a nicotine challenge. These results suggest that Zizyphus jujuba extract may attenuate nicotine-induced neurochemical and behavioral sensitization and may be effective in suppressing compulsive nicotine-seeking behavior.

• Applied Microscopy
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• v.18 no.1
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• pp.1-20
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• 1988

There's been arguments on the different morphological status between the nucleus accumbens septi and nucleus fundus striati of ventral striatum. Authors carried out the comparative study on the neuronal cell types of these nuclei, in the chick and the rat. Results are summarized as follows: In the nucleus accumbens septi of the chick, there found 3 main cell types. Type I cells are oval or spindle-shaped. They are the most abundant cell types, comprising more than 80% of neurons. The pale nucleus is usually indented. The cytoplasm is also pale and contains small amount of mitochondria, rough r-ER and Golgi complexes. This cell has a few symmetric synapses on the cell membrane. Type II cells are pale large cells. They are polygonal or irregularly-shaped. They contain pale spherical nucleus, and the pale cytoplasm with relatively large amount of mitochondria, free ribosomes and well-developed Golgi complexes. Some axo-somatic synapes are found on the cell. Type III cells are oval or spherical-shaped. The nucleus is relatively pale and large, In the dense cytoplasm, well developed. r-ER formed typical Nissl's body, and there found many mitochondria, ribosomes and lysosomes. In the chick fundus striati nucleus, there also found 3 main cell types. Type I cells are small and spindle-shaped. This type is the most abundant one and constitutes more the 80% of the neurons. Morphological features other than it's shape, is generally similar with that of Type I cell in the nucleus accumbens. Type II cells are irregularly shaped large cells. Dense cytoplasm contains large amount of cell organelles. Some axo-somatic synapses are found. Type III cells are small dense cells. This oval cell contains the oval nucleus, and the plentiful cytoplasm with well developed r-ER, ribosomes and mitochondria. In the nucleus accumbens septi of the rat, there found 4 main cell types. Type I cells are small, oval or spherical cells, comprising more than 90% of all the neurons. Spherical nucleus shows typical chromatin rim along the nuclear membrane. Dense cytoplasm contains many ribosomes and mitochondria. Type II cells are large oval cells. The eccentric nucleus is deeply invaginated. Pale cytoplasm contains large amount of ribosomes, Golgi complexes, mitochondria, and dense bodies. Type III cells are pale, large, oval cells. They contain moderate amount of ribosomes and mitochondria, and some scattered stacks of r-ER. Type IV cells are small pale cells. Small oval nucleus is indented and shows chromatin rim. Only small amount of ribosomes and mitochondria can be found. In the nucleus fundus striati of the rat, there also found 4 main cell types. Type I cells are spherical or oval cells, comprising more than 90% of the neurons. The chromatin rim of the spherical nucleus is not so prominent as compared to the rim of type I cell in the nucleus accumbens septi. The cytoplasm contains moderate amount of mitochondria, ribosomes and some scattered r-ER. A few axo-somatic synapses were found. Type II cells are small round or polygonal cells. Golgi complexes are especially well-developed in this cell type. The cytoplasm also contains moderate amount of mitochondria, ribosomes, and dense bodies. Type III cells are small cells. The large nucleus shows prominent chromatin rim. The cytoplasm contains many ribosomes and mitochondria. Type IV cells are large, spheircal or oval cells. The nucleus is deeply indented. The plentiful cytoplasm contains large amount of ribosomes, mitochondria, Golgi complexes, neurotubules, but not r-ER. In the present study, it is clear that the nucleus accumbens septi and the nucleus fundus striati are independant cell groups, according to their cytoarchitectonics and the ultrastructural features of their cell types.

• Biomolecules & Therapeutics
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• v.2 no.1
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• pp.16-22
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• 1994

Using 2 to 4 day-old postnatal rats, primary brain cell cultures were made from various brain regions (substantia nigra, hippocampus, striatum, and nucleus accumbens). Whole-cell patch clamp technique was used for electrophysiological studies. Neurons cultured from substantia nigra were characterized more in detail to test whether these cultured neurons were appropriate for physiological studies. Immunocytochemical and electrophysiological properties of these cultured neurons agreed with those from other in vivo or in vitro studies suggesting that cultured neurons maintained normal cytological and physiological conditions. Modulation of ionic channels through dopamine receptors were studied from brain areas where dopamine plays important roles on brain functions. When neurons were clamped near resting membrane potential (-74mV), R(+), R(+)-SKF 38393, a specific D$_1$receptor agonist, activated cultured striatal neurons, and dopamine itself produced biphasic responses. Responses of cultured hippocampal neurons to dopamine agonists were kinds of mirror images to those from striatal neurons; D$_1$receptor agonists inhibited hippocampal neurons but quinpirole, a D$_2$receptor agonist, activated them. Neurons cultured from nucleus accumbens were inhibited by dopamine.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.121-126
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• 2020

The ezrin-radixin-moesin (ERM) proteins are a family of membrane-associated proteins known to play roles in cell-shape determination as well as in signaling pathways. We have previously shown that amphetamine decreases phosphorylation levels of these proteins in the nucleus accumbens (NAcc), an important neuronal substrate mediating rewarding effects of drugs of abuse. In the present study, we further examined what molecular pathways may be involved in this process. By direct microinjection of LY294002, a PI3 kinase inhibitor, or of S9 peptide, a proposed GSK3β activator, into the NAcc core, we found that phosphorylation levels of ERM as well as of GSK3β in this site are simultaneously decreased. These results indicate that ERM proteins are under the regulation of Akt-GSK3β signaling pathway in the NAcc core. The present findings have a significant implication to a novel signal pathway possibly leading to structural plasticity in relation with drug addiction.

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.33-39
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• 1984

The present study was undertaken to elucidate the chracteristics in behavioral changes of chronic doses of methamphetamine on open-field activity in rats. On the other hand, the nucleus accumbens septi(NAB), one of the major areas containing mesolimbic dopaminergic terminals, has been considered to be an important site of action for dopaminergic agonists. Therefore, it also designed to investigated influence of NAB lesions. on behavioral effects of chronic-methamphetamine. Caudal and rostral areas of NAB(cr-NAB) were lesioned by applying DC of 3.0 mA for 15 sec., simultaneously. The results were as follows: 1) The rats exhibited hyperactivity after chronic administration of methamphetamine 2) The cr-NAB-lesioned rats showed a significant increase in locomotor activity only at 2 days after NAB lesions 3) Methamphetamine-induced hyperactivity was significantly decreased in the NAB-lesioned rats, and stereotyped behavior was induced instead by the drug. 4) Dopamine content of striatum was significantly decreased and serotonin content of olfactory bulb was significantly increased in NAB-lesioned rats. These results suggest that NAB plays an important role in locomotor activity and methamphetamine-induced hyperactivity.