• 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.

• 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.

• 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.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.169-174
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• 1986

Bilateral lesion of nucleus accumbens septi (N, AB), one of the mesolimbic nuclei, resulted in hyperirritability and muricide including mouse eating behavior in rats. The effects of various drugs on hyperirritability and muricide induced by NAB lesion were investigated in rats. Hyperirritability in NAB rats were significantly reduced by L-DOPA L-5-HTP major and minor tranquilizers but not reduced by MA, ATP and imipriamine-like antidepressants. On the other hand, muricide in NAB rats was significantly suppressed by L-DOPA, L-5-HTP, major and minor tranquilizers, furthermore, selectively suppressed by MA, ATP and antidepressants. These results suggested that the neural mechanism for inducing muricide is distinct from for hyperirritability in NAB rats, and that muricide in NAB rats is resulted from the increasing of cholinergic activity and reduction of dopaminergic and serotonergic activity.

• The Korean Journal of Pharmacology
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• v.21 no.2
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• pp.111-118
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• 1985

Caudal, rostral and both areas of the nucleus accumbens septi (NAB) were lesioned each in separate animal group by applying DC of 3.0 mA for 15 sec. in order to examine if any regional differences in the NAB with regard to the manifestation of locomotor activity, The r-NAB and cr-NAB-lesioned rats were significantly increased in locomotor activity but not in the c-NAB-lesioned rats and the effect following the NAB lesion was immediately produced and returned to control levels in about 7 days postoperatively. On the other hand, the locomotor stimulation produced by methamphetamine was significantly attenuated in all NAB-lesioned rats but also stereotyped behavior was significantly elicited simultaneously. These results thus suggested that NAB may be attributed to the inhibitory role in the locomotor activity, of which intensity differs from rostral site and caudal site, and stereotyped behavior may be shown higher sensitivity of the denervated striatal dopamine function.

• Applied Microscopy
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• v.35 no.3
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• pp.135-152
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• 2005

Prefrontal cortex is a psychological and metaphysical cortex, which deals with feeling, memory, planning, attention, personality, etc. And it also integrates above-mentioned events with motor control and locomotor activities. Prefrontal cortex works as a highest CNS center, since the above mentioned functions are very important for one's successful life, and further more they are upgraded every moments through memory and learning. Many of these highest functions are supposed to be generated via forebrain basal nuclei (caudate nucleus, fundus striati nucleus, accumbens septi nucleus, septal nucleus, etc.). In this experiment, prefrontal efferent terminals within basal forebrain nuclei were ultrastructurally studied. Spraque Dawley rats, weighing $250{\sim}300g$ each, were anesthetized and their heads were fixed on the stereotaxic apparatus (experimental model, David Kopf Co.). Rats were incised their scalp, perforated a 3mm-wide hole on the right side of skull at the 11mm anterior point from the frontal O point (Ref. 13, Fig. 1), suctioned out the prefrontal cortex including cortex of the frontal pole, with suction instrument. Two days following the operations, small tissue blocks of basal forebrain nuclei were punched out, fixed in 1% glutaraldehyde-1% paraformaldehyde solution followed by 2% osmium tetroxide solutions. Ultrathin sections were stained with 1% borax-toluidin blue solution, and the stained sections were obserbed with an electron microscope. Degenerating axon terminals were found within all the basal forbrain nuclei. Numbers of degenerated terminals were largest in the caudate nucleus, next in order, in the fundus striati nucleus, in the accumbens septi nucleus, and the least in the septal nucleus. Only axospinous terminals were degenerated within the caudate nucleus and the fundus striati nucleus, and they showed the characters of striatal motor control system. Axodendritic and axospinous terminals were degenerated within the accumbens septi nucleus and the lateral septal nucleus, and they showed the characters of visceral limbic system. Prefrontal role in integrating the limbic system with the striatal system, en route basal forebrain nuclei, was discussed.

• The Korean Journal of Pharmacology
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• v.23 no.2
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• pp.95-100
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• 1987

The effects of various drugs on muricide and hyperirritability induced by bilateral lesions of the nucleus accumbens septi (NAB) were investigated in comparison with those on aggression induced by midbrain raphe nuclei-lesioned rats (raphe) and olfactory bulbectomized rats (OB). Muricide in NAB, raphe and OB rats were markedly suppressed by atropine. Muricide in NAB and raphe rats were significantly suppressed by L-DOPA, L-5-HTP, but muricide in OB rats was scarcely suppressed by L-DOPA and L-5-HTP. Hyperirritability in NAB, raphe and OB rats were significantly reduced by L-DOPA and haloperidol but not suppressed by atropine. On the other hand, muricide in NAB rats was markedly suppressed by antidepressants, particularily, nomifensine, clomipramine and desipramine. Muricide in raphe rats was markedly inhibited by nomifensine and clomipramine but only slightly inhibited by desipramine. Muricide in OB rats was markedly suppressed by imipramine. Hyperirritability in NAB, raphe and OB rats were slightly suppressed by antidepressants. These results suggested that the pharmacological characteristics of aggression induced by NAB rats resembles that induced by raphe rats, but differs from that induced by OB rats. It is also suggested that employment of different types of experimentally induced muricide in rats can be useful for the evaluation of antidepressants.