• Biomolecules & Therapeutics
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• 제6권4호
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• pp.337-344
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• 1998

The objective of the present study was to investigate the effect of senescence on the binding properties of muscarinic receptors in the neostriatum of young (3 months), middle-aged (18 months) and aged (33 months) male Fischer 344 x Brown Norway hybrid rats by employing direct binding of selective radiolabeled antagonists. Using the selective M, muscarinic receptor antagonist, $[^3H]$AF-DX384, as the ligand, no significant difference in the maximal receptor density (Bmax) was observed in the neostriatum among any age-groups. In contrast, with the selective M, receptor antagonist, $[^3H]$4-DAMP, a significant increase in the number of muscarinic receptors was observed in neostriatal membrane fractions prepared from the aged animals relative to that observed in the young rats. For each ligand there was no age-related change in its affinity (Kd) for the muscarinic receptors. These results indicate that the observed age-related changes in the muscarinic receptor density may not be necessarily decremuntal and depend upon the muscarinic receptor subtype examined.

• Biomolecules & Therapeutics
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• 제2권1호
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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.

• Archives of Pharmacal Research
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• 제18권4호
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• pp.271-276
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• 1995

Changes in the distribution of dopamine and its metabolites, activities of monoamine oxidase, and dopamine uptake were studied inhyperglycemic rat striatum. The hyperglycemia was induced by the administration of streptozotocin (STZ, 40 mg/kg, i.p. for 3 days.). The levels of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid were significantly decreased without change in dopamine level in the synatic cleft 14 days after STZ treatment. In the synaptosome, the dopamine level, however, was significanly increased after the treatment. But the DOPAC level in the synaptosome was decreased 14 days after the treatment. The affinity of dopamine uptake was significantly decreased without changes in the velocity 14 days after the treatment. However the response to uptqke inhibitor was unchanged. The striatal monoamine oxidase activities were also decreased in the hyperglycemic state. These results indicate that various parameters of striatal dopamine activities were decreased in the hyperglycemic rats. Furthermore, it suggests that the increase in dopamine level of synaptosome might be due to the decrease in the release of dopaine in hyperglycemic state.

• 약학회지
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• 제32권1호
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• pp.50-54
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• 1988

A simple and sensitive method was studied for the simultaneous determination of catecholamine, indoleamine and their related metabolites by high performance liquid chromatography with electrochemical detector. Norepinephrine, dopamine, serotonin and their metabolites of 3,4-dihydroxyphenylacetic acid, homovanillic acid, 5-indoleacetic acid were resolved from rat brain tissue homogenates by separation on reversed phase $C_{18}$ column with mobile phase consisting of monochloroacetate buffer (pH2.47), 1.42mM sodium octyl sulfonate and 7% acetonitrile. Both catechols and indoles can be eluted in 15min. The sensitivities of this method are sufficient for determination of at least 100 pg of neurochemical amines in brain samples, for example, frontal cortex, olfactory bulb, striatum, septum, hippocampus, thalamus, hypothalamus, medulla & pons and cerebellum. The highest level of dopamine was observed in striatum whereas norepinephrine and serotonin were in hypothalamus.

• 약학회지
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• 제42권1호
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• pp.95-100
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• 1998

Male Sprague-Dawley rats were exposed to the toluene at 3,000${\pm}$200ppm via inhalation for two hours (single inhalation group), three weeks by two hours per day, six days per wee k (repeated inhalation group). We examined the level of excitatory amino acids of the extracellular neurotransmitter within the corpus striatum of rats by using in vivo microdialysis. Aspartate (Asp) and glutamate (Glu) of excitatory amino acid neurotransmitters were generally decreased in the inhalation groups compared with the control group, and more significantly decreased in the repeated inhalation group than in the single inhalation group except that Asp was increased from 60 min after the beginning of the inhalation to 30 min after the termination.

• BMB Reports
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• 제28권2호
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• pp.177-183
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• 1995

The activity of aldehyde dehydrogenase (ALDH) in the cerebrum, cerebellum, striatum, and medulla oblongata was examined and mitochondrial matrix ALDH was purified prior to immunohistochemical study on the localization of ALDH isozymes in pig brain. Relatively high enzyme activity was found in the striatum and medulla oblongata when using indole-3-acetaldehyde as substrate, and in the striatum when using 3,4-dihydroxyphenylacetaldehyde (DOPAL). The main part of mitochondrial ALDH activities with both acetaldehyde and DOPAL existed in the matrix fraction. The ratio of activity of the matrix to the membrane fraction in the cerebrum was higher than in the cerebellum, suggesting that the distribution pattern of ALDH isozymes was different according to the brain regions. The 276-fold purified mitochondrial matrix ALDH from pig brain was identified to be homologous tetramers with 53 KD subunits. The enzyme showed maximal activity at pH 9.0 and was stable in the temperature range from $25^{\circ}C$ to $37^{\circ}C$. The mitochondrial matrix ALDH activity was considerably inhibited by acetaldehyde in vitro. The $K_m$ values of the enzyme for acetaldehyde and propionaldehyde were 5.8 mM and 4.9 mM, respectively, whereas $K_m$ values for indole-3-acetaldehyde and DOPAL were 44 ${\mu}M$ and 1.6 ${\mu}M$, respectively. The $V_{max}/K_{m}$ ratio was the highest with DOPAL as compared with other substrates. These results suggested that mitochondrial matrix ALDH in the present work might be a low Km isozyme involved in biogenic aldehyde oxidation in pig brain.

• The Korean Journal of Physiology and Pharmacology
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• 제9권5호
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• pp.263-268
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• 2005

Striatum has important roles in motor control, habitual learning and memory. It receives glutamatergic inputs from neocortex and thalamus, and dopaminergic inputs from substantia nigra. We examined effects of dopamine (DA) on the corticostriatal synaptic transmission using in vitro extracellular recording technique in rat brain corticostriatal slices. Synaptic responses were elicited by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. Corticostriatal population spike (PS) amplitudes were decreased ($39.4{\pm}7.9$%) by the application of $100{\mu}M$ DA. We applied receptor subtype specific agonists and antagonists and characterized the modulation of corticostriatal synaptic transmission by different DA receptor subtypes. $D_2$ receptor agonist (quinpirole), antagonist (sulpiride), and $D_1$ receptor antagonist (SKF 83566), but not $D_1$ receptor agonist (SKF 38393), induced significantly the reduction of striatal PS. Pretreatment neither with SKF 83566 nor sulpiride significantly affected corticostriatal synaptic inhibition by DA. However, the inhibition of DA was completely blocked by pretreatment with mixed solution of both SKF 83566 and sulpiride. These results suggest that DA inhibits corticostriatal synaptic transmission through both $D_1$ and $D_2$ receptors in concert with each other.

• 감성과학
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• 제14권4호
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• pp.555-570
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• 2011

도덕적으로 옳다고 여겨지는 행동을 실천하기 위해서는 친사회적-도덕적 행위에 대한 동기 부여가 필요하다. 선행 연구들을 통해 도덕적 행위의 동기 부여에 감정이 중요한 역할을 한다는 것이 밝혀졌다. 이는 기능성 자기 공명 영상 장치(functional magnetic resonance imaging, fMRI)를 사용한 인지 신경 과학 분야의 연구들을 통해 실제 보상 및 동기에 관여하는 영역으로 알려진 복측 선조체(ventral striatum, VS)의 활성화를 발견함으로써 확인되었다. 원래 VS는 보상 반응의 핵심적 영역으로 물질적 보상에 민감하게 반응하는 것으로 알려졌으나 최근에는 사회적 보상이 주어졌을 때, 친사회적 감정을 강하게 경험할 때에도 활성화되는 것이 관찰되었다. 그러나 도덕적 의사결정이 필요한 사회적 상황에서 친사회적 도덕감을 경험할 때 보상에 민감한 영역인 VS가 활성화되는 이유에 대한 설명은 아직 명확하지 않다. 따라서 본 리뷰 연구에서는 도덕적 의사결정상황에서 감정의 동기 부여 역할 및 관련 신경 기제에 대해 알아보고, VS를 중심으로 도덕적 의사결정에 관여하는 신경 네트워크 구조를 개관함으로써 친사회적, 도덕적으로 동기 부여가 되는 도덕적 의사결정 상황 및 그 이유에 대해 알아보고자 하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권6호
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• pp.295-301
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• 2003

Striatum plays a crucial role in the movement control and habitual learning. It receives an information from wide area of cerebral cortex as well as an extensive serotonergic (5-hydroxytryptamine, 5-HT) input from raphe nuclei. In the present study, the effects of 5-HT to modulate synaptic transmission were studied in the rat corticostriatal brain slice using in vitro extracellular recording technique. Synaptic responses were evoked by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. 5-HT reversibly inhibited coticostriatal glutamatergic synaptic transmission in a dose-dependent fashion (5, 10, 50, and $10{\mu}M$), maximally reducing in the corticostriatal population spike (PS) amplitude to $40.1{\pm}5.0$% at a concentration of $50{\mu}M$ 5-HT. PSs mediated by non-NMDA glutamate receptors, which were isolated by bath application of the NMDA receptor antagonist, d,l-2-amino-5-phospohonovaleric acid (AP-V), were decreased by application of $50{\mu}M$ 5-HT. However, PSs mediated by NMDA receptors, that were activated by application of zero $Mg^{2+}$ aCSF, were not significantly affected by $50{\mu}M$ 5-HT. To test whether the corticostriatal synaptic inhibitions by 5-HT might involve a change in the probability of neurotransmitter release from presynaptic nerve terminals, we measured the paired-pulse ratio (PPR) evoked by 2 identical pulses (50 ms interpulse interval), and found that PPR was increased ($33.4{\pm}5.2$%) by 5-HT, reflecting decreased neurotransmitter releasing probability. These results suggest that 5-HT may decrease neurotransmitter release probability of glutamatergic corticostriatal synapse and may be able to selectively decrease non-NMDA glutamate receptor-mediated synaptic transmission.

• 대한간호학회지
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• 제41권6호
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• pp.834-842
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• 2011

Purpose: The purpose of this study was to determine the effect of dehydroepiandrosterone (DHEA) on recovery of muscle atrophy induced by Parkinson's disease. Methods: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 20 ${\mu}g$) into the left striatum using stereotaxic surgery. Rats were divided into two groups; the Parkinson's disease group with vehicle treatment (Vehicle; n=12) or DHEA treatment group (DHEA; n=22). DHEA or vehicle was administrated intraperitoneally daily at a dose of 0.34 mmol/kg for 21 days. At 22-days after DHEA treatment, soleus, plantaris, and striatum were dissected. Results: The DHEA group showed significant increase (p<.01) in the number of tyrosine hydroxylase (TH) positive neurons in the lesioned side substantia nigra compared to the vehicle group. Weights and Type I fiber cross-sectional areas of the contralateral soleus of the DHEA group were significantly greater than those of the vehicle group (p=.02, p=.00). Moreover, extracellular signal-regulated kinase (ERK) phosphorylation significantly decreased in the lesioned striatum, but was recovered with DHEA and also in the contralateral soleus muscle, Akt and ERK phosphorylation recovered significantly and the expression level of myosin heavy chain also recovered by DHEA treatment. Conclusion: Our results suggest that DHEA treatment recovers Parkinson's disease induced contralateral soleus muscle atrophy through Akt and ERK phosphorylation.