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Boletin de estudios medicos y biologicos最新文献

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A new pattern of neuronal firing in the suprachiasmatic nucleus in vitro and a possible mechanism which induces rhythmicity. 一种体外视交叉上核神经元放电的新模式及其诱发节律性的可能机制。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
L Zhang, R Aguilar-Roblero, R A Barrio
{"title":"A new pattern of neuronal firing in the suprachiasmatic nucleus in vitro and a possible mechanism which induces rhythmicity.","authors":"L Zhang,&nbsp;R Aguilar-Roblero,&nbsp;R A Barrio","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Electrophysiological studies of neurons in the suprachiasmatic nucleus, of rat brain slices in vitro, reveal characteristic firing patterns which have been previously classified as regular, irregular and bursting. A new kind of neuronal firing is found, by means of an interspike interval distribution analysis. Based on these results a new classification scheme is suggested. A model to explain the presence of all the experimental patterns is delivered. The model not only suffices to infer the presence of regular oscillators, but also suggests interesting consequences concerning the components of the circadian system and their statistical behavior.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"31-40"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12511161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The importance of employing homologous serum free of thyronines in radioimmunoassays to assess circulating thyroid hormones in rainbow trout. 用不含甲状腺原氨酸的同源血清放射免疫测定虹鳟鱼循环甲状腺激素的重要性。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
A Orozco, A Ruiz, C Valverde
{"title":"The importance of employing homologous serum free of thyronines in radioimmunoassays to assess circulating thyroid hormones in rainbow trout.","authors":"A Orozco,&nbsp;A Ruiz,&nbsp;C Valverde","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Although abundant, available information regarding the values of circulating thyronines in the rainbow trout is misleading and confusing. The present study demonstrates the importance of maintaining species serum-homology when measuring thyronines with RIA to avoid spurious results. The utilization of homologous (trout) serum free of thyronines in the standard curve allowed the standardization of accurate and specific radioimmunoassays to quantitate circulating T3 and T4 levels in 10 microliters of rainbow trout serum. Detection limit was 50 pg for both thyronines. Inter- and intra-assay coefficients of variation were minor to 10%. Mean values for T3 and T4 +/- SEM in the trout population studied (n = 34) were 23.6 +/- 1.2 and 12.0 +/- 2.3 ng/ml respectively. A positive and significant correlation (p < 0.005) between body weight and T3 was observed, confirming the active participation of this thyronine in growth processes.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"41-7"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12471253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Rapidly recurring cortical seizures induce changes in neuronal responsiveness to acetylcholine. 快速反复发作的皮层癫痫引起神经元对乙酰胆碱反应的改变。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
H Solís, J Bravo, J A Galindo-Morales
{"title":"Rapidly recurring cortical seizures induce changes in neuronal responsiveness to acetylcholine.","authors":"H Solís,&nbsp;J Bravo,&nbsp;J A Galindo-Morales","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The majority of mechanisms proposed to explain epileptic discharge suggest an excessive synaptic input into the cell or possible changes in cellular excitability which result in a decreased firing threshold and in the presence of self-sustained activity. It is likely that these changes are caused by modifications in the membrane receptor sensitivity to a specific neurotransmitter. In view of the above, the purpose of the present study has been to evaluate the sensitivity of the postsynaptic receptor by means of the microiontophoretic applications of substances whose pharmacological effect is known, thus determining its possible involvement in the epileptic process. Changes in cortical excitability were induced by electric stimuli in the sensorimotor cortex of rats anesthetized with urethane (1 g/kg intraperitoneally), immobilized with pancuronium bromide and kept alive with mechanical respiration. The electric stimuli consisted of trains of biphasic pulses, each lasting one millisecond, with a frequency of 100 pps and with a train duration of 1 second. The response of the neuron to acetylcholine was evaluated before and after the kindling had been established. The dosage was measured in nanoamperes of microiontophoretic ejecting current. Extracellular field potentials were recorded with the central barrel of 4-barrel micropipettes. Peripheral barrels were used for iontophoretic applications of Acetylcholine (Ach .1, 1M), Atropine (25mM). One of these barrels containing NaCl (2M) was used for the automatic passage of balancing current.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"49-56"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12471256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Amygdalar catecholaminergic input to septal nuclei, relation to clomipramine actions on lateral septal neurons in the rat. 杏仁体儿茶酚胺能输入到间隔核，与氯咪嗪对外侧间隔神经元的作用有关。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
C M Contreras, L Chacón, M L Marván, M A Guzmán-Sáenz
{"title":"Amygdalar catecholaminergic input to septal nuclei, relation to clomipramine actions on lateral septal neurons in the rat.","authors":"C M Contreras,&nbsp;L Chacón,&nbsp;M L Marván,&nbsp;M A Guzmán-Sáenz","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Antidepressants exert mixed actions on serotonergic and catecholaminergic systems. However, it is unknown whether a catecholaminergic blockade impinge on the actions of a tricyclic with serotonergic agonist properties (clomipramine) in limbic structures. The aim of the present study is to explore the effects of a catecholaminergic lesion in the basolateral amygdala on the firing rate of lateral septal, and hippocampal neurons in rats treated with clomipramine. An amygdaline lesion with 6-OHDA resembled the actions of clomipramine on the firing rate in lateral septal neurons, i.e. an increased rate of firing. However, the lesion blocked further effects of clomipramine on septal firing. Clomipramine decreased the firing rate in hippocampal neurons; however, neither the 6-OHDA lesion nor the added treatment with clomipramine modified the firing rate. It is concluded that an intact catecholaminergic amygdaloid input to lateral septal nuclei is necessary for clomipramine actions; however, the initial action of the tricyclic may involve a catecholaminergic blockade.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"9-13"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12512347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Septal neurons related with hippocampus increase their firing rate after long-term clomipramine. 与海马相关的间隔神经元长期服用氯丙帕明后放电频率增加。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
M L Marván, M A Guzmán-Sáenz, J Alberto Barradas, C M Contreras
{"title":"Septal neurons related with hippocampus increase their firing rate after long-term clomipramine.","authors":"M L Marván,&nbsp;M A Guzmán-Sáenz,&nbsp;J Alberto Barradas,&nbsp;C M Contreras","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In the rat, long-term clomipramine increases the firing rate in lateral septal neurons. Although the hippocampus is the main afference for septal nuclei, it is unknown whether clomipramine increases the firing rate in most of hippocampal-septal neurons. Therefore, the present study explored the actions of long-term clomipramine in lateral septal neurons identified by their relation to the hippocampus. In most recordings, hippocampal stimulation produced a brief excitatory short-latency response, followed by a period of inhibition of firing. These neurons increased their firing rate after clomipramine treatment. Other septal neurons not respondent to hippocampal stimulation did not respond to clomipramine treatment, either. We concluded that only hippocampal-septal neurons are clomipramine responders too, and the drug-induced enhancement of firing rate is likely to be mediated by an interneuron-mediated disinhibition process.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"15-20"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12471251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Cortical and septal responses to dorsal raphe nucleus stimulation in the rat: long-term clomipramine actions. 大鼠中缝背核刺激的皮层和隔叶反应:长期氯咪嗪的作用。
Boletin de estudios medicos y biologicos Pub Date : 1992-01-01
C M Contreras, M L Marván, A Muñoz-Méndez, A Ramírez-Morales
{"title":"Cortical and septal responses to dorsal raphe nucleus stimulation in the rat: long-term clomipramine actions.","authors":"C M Contreras,&nbsp;M L Marván,&nbsp;A Muñoz-Méndez,&nbsp;A Ramírez-Morales","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In cerebral cortex and lateral septal nuclei different serotonergic receptor subtypes coexist, thus a different action on neuronal firing may be expected depending on the receptor activated. Dorsal raphe nucleus stimulation produced an increased rate of firing in cortical layer V, and in lateral septal nuclei. However, firing rate in cortical layer VI remained unchanged after stimulating the dorsal raphe nucleus. Clomipramine is a tricyclic which exerts its main actions on serotonergic receptors, and long-term treatment with this antidepressant produced a selective increased firing rate in lateral septal neurons, but not in cortical neurons. From an electrophysiological point of view, it is concluded that the excitatory actions on firing rate elicited by dorsal raphe nucleus stimulation or clomipramine treatment are mediated by 5-HT2 receptor subtype activation which is likely to be acting as a 5-HT1A modulator in such places where both receptor subtypes coexist.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"40 1-4","pages":"3-7"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12471254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nutrition and undernutrition in the valley of Mexico: possible transgenerational influences. 墨西哥山谷的营养和营养不良:可能的跨代影响。
Boletin de estudios medicos y biologicos Pub Date : 1991-01-01
M Salas, C Torrero
{"title":"Nutrition and undernutrition in the valley of Mexico: possible transgenerational influences.","authors":"M Salas,&nbsp;C Torrero","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The dietary quality of several generations of inhabitants living in the Valley of Mexico City, was examined on the light of recent information obtained from experimental undernutrition studies. Socioeconomic status and environmental limitations were also considered. This essay proposes that some transgenerational effects described in animal models, such as the diminished brain and body weight, the low cerebral DNA content, the hypermotility and some learning disabilities could have equivalents in the chronically undernourished population of the Valley of Mexico City.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"39 1-4","pages":"29-32"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12976251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Clomipramine actions on firing rate in septal nuclei of the rat are not related to anaesthesia (urethane). 氯丙咪嗪对大鼠间隔核放电率的影响与麻醉(氨基甲酸乙酯)无关。
Boletin de estudios medicos y biologicos Pub Date : 1991-01-01
C M Contreras, M L Marván, H Lara-Morales, A Barradas, L Chacón, M A Guzmán-Sáenz, C Márquez Flores
{"title":"Clomipramine actions on firing rate in septal nuclei of the rat are not related to anaesthesia (urethane).","authors":"C M Contreras,&nbsp;M L Marván,&nbsp;H Lara-Morales,&nbsp;A Barradas,&nbsp;L Chacón,&nbsp;M A Guzmán-Sáenz,&nbsp;C Márquez Flores","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>An increased firing rate in lateral septal nuclei (LSN) appears in urethane-anesthetized rats after several acute drug and non-drug human antidepressant treatments. A still more pronounced increase in firing rate is produced in LSN after clomipramine (CMI) long-term treatment. In spite of urethane is a widely used anesthetic for single unit extracellular recordings, it modifies evoked potentials wave-form. Therefore, present study discards urethane interaction with CMI in LSN single unit extracellular recordings. CMI was acutely injected (1.25 mg/kg: IP) either to urethane-anesthetized, or non-anesthetized encephale-isolé rats. The CMI treated groups showed higher rates of firing in LSN regardless of the use of general anesthesia during recordings. Another group of urethane-anesthetized rats received intracerebroventricular (ICV) microinjections of CMI (100 micrograms/10 microliters/1 min). An amount of 42.8% of LSN-recorded neurons responded with a long-lasting increased firing rate. Results discard urethane and CMI interactions. Additionally, systemic actions of CMI on firing rate of LSN are reproduced by ICV/route microinjections.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"39 1-4","pages":"3-8"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12976975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Behavioral and electrophysiological patterns of wakefulness-sleep states in a lizard. 蜥蜴清醒-睡眠状态的行为和电生理模式。
Boletin de estudios medicos y biologicos Pub Date : 1991-01-01
F Ayala-Guerrero, S Huitrón Reséndiz
{"title":"Behavioral and electrophysiological patterns of wakefulness-sleep states in a lizard.","authors":"F Ayala-Guerrero,&nbsp;S Huitrón Reséndiz","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Four individuals of the lizard Ctenosaura pectinata were chronically implanted for electroencephalographic (EEG), electromyographic (EMG) and electro-oculographic (EOG) recordings. Four different vigilance states were observed throughout the nyctohemeral cycle. These states were: Active wakefulness (Aw), quiet wakefulness (Qw), quiet sleep (Qs) and active sleep (As). Each state displayed its own behavioral and electrophysiological characteristics. EEG waves were similar during Aw and Qw but they diminished in amplitude and frequency when passing from these states to Qs, and both parameters increased during As. Muscular activity was intense in Aw, it decreased during Qw and almost disappeared during Qs. This activity reappeared in a phasic way during As, coinciding with generalized motor manifestations. Ocular activity was intense during Aw but minimal during Qw, it disappeared in Qs and was present intermittently in As. Aw, Qw, Qs and As occupied 5.9%, 25.7%, 67.7% and 0.6% of the 24 hr period, respectively. The frequency and duration of As episodes showed great inter-animal variability and the mean duration was of 12.9 sec. Stimuli reaction threshold was highest during sleep. In conclusion, the lizard Ctenosaura pectinata exhibit two sleep phases (Qs and As) that may be assimilated to slow wave sleep (SWS) and paradoxical sleep (PS) of birds and mammals.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"39 1-4","pages":"9-14"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12976977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Technical note: removal of the unfragmented pituitary gland (hypophysectomy) in the rat. 技术说明:切除大鼠未破碎的脑垂体(垂体切除术)。
Boletin de estudios medicos y biologicos Pub Date : 1991-01-01
R Alvarez-Buylla, A Q Quintanar Stephano, J L Quintanar Stephano, E De Alvarez-Buylla
{"title":"Technical note: removal of the unfragmented pituitary gland (hypophysectomy) in the rat.","authors":"R Alvarez-Buylla,&nbsp;A Q Quintanar Stephano,&nbsp;J L Quintanar Stephano,&nbsp;E De Alvarez-Buylla","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>A technique to excise the pituitary gland (hypophysis) in rats is described. The basisphenoid bone is reached from the ventral neck and is perforated to expose the pituitary gland and its stalk. An aspirator allows the removal of the hypophysis and the stalk, including pars tuberalis, in one piece. The advantages of this new technique include: 1) immediate verification of the entirety of hypophysectomy; 2) broad operating field which exposes the pituitary stalk up to the hypothalamus; 3) the use of tracheal intubation and artificial respiration to improve postoperative recovery and to allow expanded operation field even during prolonged surgery. Pre- and postoperative care are described. The mean survival rate after this type of operation was 79% in rats weighing 50 to 130 g and 90% in rats larger than 130 g.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"39 1-4","pages":"33-8"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12976976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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