Motivated behavior and the estrous cycle in rats

(1) The estrous cycle in the rat may be used to study recurrent changes in motor behaviors and motivation which are strongly related to cyclic hormonal and CNS changes. (2) The peak in motivated behaviors occurs during a sharply defined period on the night between proestrus and estrus and is evident in facilitated wheel-running, lordosis, and intracranial self-stimulation. (3) Behaviors without a clearly motivated character do not show an estrous cyclicity. (4) The estrous cyclic variation in intracranial self-stimulation was observed at a specific locus — the pars campacta of the substantia nigra. (5) A neurochemical link between sexually motivated behavior, wheel running and intracranial self-stimulation is suggested. This link is in part dopaminergic but is probably also activated by many other systems.     

下丘脑错构瘤214例临床特征分析

目的 分析下丘脑错构瘤的临床特征.方法 回顾分析1994年1月至2008年5月北京天坛医院诊治的214例下丘脑错构瘤的临床资料.结果 性别:男性多于女性,男女之比为1.52:1;有性早熟的115例中,男女之比为1.09:1;有癫痫的123例中男女之比为2.15:1;有痴笑样癫痫的96例中男女之比为2:1;同时表现为性早熟及癫痫的38例中男女之比为1.38:1.发病年龄:200例有症状的病例,平均发病年龄为34.5个月;发病年龄≤3岁者157例,占78.5%;单纯性早熟者77例(38.5%),平均发病年龄16.5个月,<3岁者67例,占87%;表现有性早熟者115例(57.5%),平均发病年龄为17.63个月,发病<3岁者99例,占86.1%;有痴笑样癫痫者96例(48%),平均为26.14个月,<3岁者有78例,占81.3%;所有癫痫者[痴笑样癫痫和(或)癫痫大、小发作]123例(61.5%),平均发病年龄为3.81岁,≤3岁前发病者有90例,占73.2%.结论 下丘脑错构瘤多数在婴幼儿期发病,男性多于女性.     

Hypothalamic hamartoma with bilateral anophthalmia

Introduction Hypothalamic hamartomas are congenital malformations. Clinically, they can be asymptomatic, but they cause seizures, mental retardation and precocious puberty in many cases. Case report A 20-day-old boy with hypothalamic hamartoma and bilateral anophthalmia was presented. Except those, no other congenital anomaly was detected. Conclusion This is a rare case of hypothalamic hamartoma with bilateral anophthalmia. The mutations at SOX2 has an important role in the developing brain and eyes.     

大鼠下丘脑弓状核的形态计量研究

为了探讨急性癫痫弓状核形态改变与可复性，我们采用光、电镜技术和形态计量方法对下丘脑弓状核进行了形态定量研究。结果显示：弓状核切面面积为317500±6460um2，神经元胞体和胞核的等效直径分别为12.94±0.34um和8.54±0.43um，暗细胞内线粒体、粗面内质网、高尔基复合体、溶酶体、游离核相体和分泌颗粒的面积分数分别是5.87±1.98％、3.53±0.25％、0.81±0.49％、2.13±0.42％、10.53±0.46％和0.86±0.35％，其面数密度（单位面积为30um2）分别为15.68±1.14um-2、21.29±3.52um-2、10.20±0.42um-2、5.62±067um-2、101.35±7.55um-2和5.22±0.77um-2.本文还对弓状核的形态结构、神经元类型及其功能进行了讨论。     

Schedule-controlled brain self-stimulation: Has it utility for behavioral pharmacology?

We review evidence that schedule-controlled intracranial self-stimulation (ICSS) has properties in common with conventional reinforcements, such as food and water, but unlike the latter, animals will respond for ICSS for long periods of time at a near-constant rate. Schedule-controlled ICSS has proven to be more sensitive to drug-induced changes than has ICSS on a continuous reinforcement schedule, and it permits a more fine-grained analysis of the pattern of responding that results in the reinforcement. Evidence is accumulating that the schedule of ICSS itself leads to neurochemical changes in areas of the brain, such as the nucleus accumbens, in which reward processes occur. Results obtained from schedule-controlled ICSS would complement those obtained by drug self-administration studies which generally use intermittent reinforcement. A systematic examination of ICSS schedules at different brain sites would greatly facilitate our interpretation of drug effects and this would have utility for behavioral pharmacology.     

经胼胝体穹隆间人路切除下丘脑内型错构瘤

目的探讨下丘脑内型错构瘤的手术治疗方法。方法报告4例下丘脑内型错构瘤,采用右额后开颅经胼胝体-透明隔-穹隆间入路切除下丘脑内型错构瘤。结果4例均为儿童,男女为31,均以癫痫发作为主要症状,错构瘤为大部切除或部分切除,术后低钠血症1例,轻度尿崩1例,无其他合并症。随诊半年至1.5年,无任何癫痫发作。结论经胼胝体-透明膈-穹隆间入路是下丘脑内型错构瘤的最佳手术入路,错构瘤大部切除或部分切除即可取得满意疗效。     

Surgical Treatment of Intractable Seizures Due to Hypothalamic Hamartoma

Summary: A 6.5-year-old boy developed seizures at age 2.8 years consisting of episodes of unconsciousness and laughing attacks. By age 6 years, multiple seizure types, including generalized tonic-clonic (GTC), complex partial (CPS) and akinetic seizures, and drop attacks were occurring several times daily. EEG showed multifocal epileptic discharges. Antiepileptic drugs (AEDs) did not control the seizures. With progression of the epilepsy, cognitive deterioration developed. There were no manifestations of precocious puberty. Neuroimaging disclosed a suprasellar mass in continuity with the hypothalamus, and a diagnosis of hypothalamic hamartoma was made. After surgical resection of the hamartoma, the seizures were completely alleviated, and the epileptic EEG discharges disappeared. Improvement of mental function was also noted.     

The role of the dopaminergic projections in MFB self-stimulation

Psychophysical experiments indicate that the first stage of the reward pathway in medial forebrain bundle self-stimulation consists of small myelinated descending axons. Pharmacological experiments show that neuroleptics attenuate or abolish the rewarding effect. This had led to the hypothesis that the descending myelinated axons synapse on an ascending dopaminergic second stage projection. 2-Deoxy-[¹⁴C]glucose autoradiography in self-stimulating animals or animals receiving automatically administered rewarding stimulation after treatment with reward-blocking doses of pimozide reveals activation of a descending myelinated system but no stimulation-produced activation of an ascending dopaminergic projection system, even though the autoradiographic method reveals the mild elevations and depressions of activity in dopaminergic terminal fields consequent upon injections of neuroleptics and amphetamine, respectively, and the strong activation of the nigrostriatal projection produced by stimulating directly in the substantia nigra. When the effects of neuroleptics and clonidine are measured by the psychophysical method (that is, by lateral shifts in the rate-frequency function), it is found that both drugs produce only gradual and rather small attenuations of rewarding efficacy up to doses at which it is no longer possible to measure their effects. It is suggested that, for neuroleptics at least, the rewarding effect abruptly fails at these doses. It is further suggested that these drugs do not act on the rewarding pathway itself, but on the process by which the rewarding signal is converted to an enduring rewarding effect.     

The effects of ambient and hypothalamic temperatures on the hyperthermic responses to prostaglandins E1 and E2

Summary The effects of ambient and hypothalamic temperatures were studied on the hyperthermic responses to prostaglandins E₁ and E₂ (PGE₁ and PGE₂) injected intraventricularly in the unanesthetized rabbit. Hyperthermic responses to PGE₁ observed at different thermal environments were approximately equal in magnitude and time course. However, the prevailing ambient temperature influenced the thermoregulatory mechanisms by which the hyperthermia was achieved. In a hot environment, PGE₁-hyperthermia was brought about by suppression of heat loss mechanism with little change in heat production. During cold exposure body temperature was raised mainly by an increase in heat production without a significant change in heat loss. PGEs-hyperthermias were attenuated by warming and enhanced by cooling the anterior hypothalamus. These changes in the hyperthermic responses to PGE₁ and PGE₂ are in contrast to those obtained with intraventricular injection of noradrenaline at different ambient temperatures and during hypothalamic heating and cooling. It is therefore unlikely that noradrenaline is involved in the hyperthermic responses to PGEs. On the other hand, the results support the view that prostaglandins may be mediators of pyrogen-induced fever.     

Effects of dopamine agonists on hypothalamic defensive attack in cats

The effects of methamphetamine (MAT) and apomorphine (APO), dopamine agonists, were studied in 16 cats to evaluate their effects on threshold for defensive attack behavior elicited by electrical stimulation of the ventromedial hypothalamic nucleus (VMH). Directed attack and hissing were selected from elementary responses as constituting a defensive attack. Hissing threshold was measured in two situations, one with human provocation and the other without provocation. MAT administered systemically lowered the thresholds for all three types of responses in a dose-related manner (0.5, 1.0, and 3.0 mg/kg). The effects of 1.0 mg/kg of APO were almost identical to those observed with 0.5 or 1.0 mg/kg of MAT. These results suggest that MAT-induced aggressive behavior may be mediated by a dopamine-induced increase in the excitability of the VMH.