Self-administration of the GABA(A) agonist muscimol into the medial septum: dependence on dopaminergic mechanisms.

International audienceRATIONALE: Reinforcement in the medial septal division (MSDB) might involve local GABAergic mechanisms. OBJECTIVES: We used intracranial self-administration to determine whether the GABA(A) agonist muscimol or antagonist bicuculline might have rewarding effects when infused into the MSDB. We assessed the anatomical specificity of muscimol intra-MSDB self-administration by injecting this molecule into the nucleus accumbens (NAc). Finally, we evaluated the involvement of dopaminergic mechanisms in muscimol self-administration. MATERIALS AND METHODS: BALB/c mice were implanted with a guide cannula targeting the MSDB or the NAc. They were trained to discriminate between the two arms of a Y-maze, one arm being reinforced by muscimol or bicuculline injections. Another group of MSDB implanted mice was pre-treated intraperitoneally before muscimol self-administration with a D1 (SCH23390) or D2/D3 (sulpiride) receptor antagonist or vehicle. A last group of MSDB mice received additional bilateral guide cannulae targeting the ventral tegmental area (VTA) or a more dorsal region to assess the effects of intra-VTA injection of SCH23390 on intra-MSDB muscimol self-administration. RESULTS: Mice self-administered intra-MSDB muscimol (0.6, 1.2, or 12 ng/50 nl), but not bicuculline (1.5 or 3 ng/50 nl). Systemic pre-treatment with SCH23390 (25 mug/kg) or sulpiride (50 mg/kg) or bilateral injection of SCH23390 (0.25 mug/0.1 mul) into the VTA prevented acquisition of intra-MSDB muscimol self-administration. CONCLUSION: The activation of GABA(A) receptors in the MSDB supports self-administration, and dopamine release from the VTA may be involved in the acquisition of this behaviour. The MSDB could represent a common brain substrate for the rewarding properties of drugs facilitating GABA(A) tone

Supernova: Jonge Belgische Architectuur. Jeune Architecture Belge

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Transcranial Doppler to assess sepsis-associated encephalopathy in critically ill patients.

Transcranial Doppler can detect cerebral perfusion alteration in septic patients. We correlate static Transcranial Doppler findings with clinical signs of sepsis-associated encephalopathy.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Dépistage du risque de déclin fonctionnel par une équipe gériatrique mobile au sein d'un hôpital général

The Mobile Geriatric Team (MGT) is part of the Geriatric Care Program and aims to provide interdisciplinary geriatric expertise to other professionals for old patients hospitalized outside geriatric department. Our hospital has a MGT since 2008. Our objective is to retrospectively describe the population of patients of 75 years and older hospitalized outside the geriatric ward and screened for the risk of functional decline by the MGT between 1 October 2009 and 30 September 2011. We recorded the risk of functional decline, as indicated by the Identification of Senior At Risk score (ISAR) performed within 48 h after admission, place of living, discharge destination, Mini Mental State Examination (MMSE) and Geriatric Depression Scale (GDS) scores. In two years, 1.568 patients ≥ 75 Y were screened with the ISAR score (mean age 82.5 Y, 60.7% of women). We identified 833 patients with a high-risk of functional decline (ISAR ≥ 3). The majority of high-risk subjects (78%) were living at home before hospitalization and 58.7% returned home after discharge. Depression and cognitive impairment were identified among respectively 41% and 59% of high-risk subjects. Only 128 patients were admitted for fall. Most of the faller patients were living at home prior hospitalization and had an ISAR score ≥ 3. The MGT allowed identifying many patients ≥ 75 Y living at home and presenting with high-risk of functional decline and geriatric syndromes, confirming that good screening procedures are necessary to optimize management of hospitalized olders. Most of faller patients have an ISAR score ≥ 3 and should benefit a comprehensive geriatric assessment.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cerebral perfusion alterations and cognitive decline in critically ill sepsis survivors

Introduction: We investigated the association between cerebral perfusion perturbations in sepsis with possible cognitive decline (CD) after patients’ discharge from the intensive care unit (ICU). Methods: We studied 28 patients with sepsis and Lawton’s Instrumental Activities of Daily Living scale (IADL) scores ≥5 who were discharged from a university ICU institution. We evaluated cerebral circulatory parameters (pulsatility index (PI) and cerebral blood flow index (CBFi) was calculated based on the measured velocity of the middle cerebral artery. Use of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) test was performed daily, and either the Mini Mental State Examination test (MMSE) or Clock Drawing test was performed at ICU discharge. CD was categorized as persistent coma, positive CAM-ICU test at discharge, MMSE <24, or an abnormal Clock test. Results: Patients had a median pre-ICU IADL score of 6.3 (95% CI 5.9–6.7). Fourteen patients (50%) had CD at discharge. Two were in persistent coma despite sepsis resolution. Information recall was the most affected mental function of the other 12 patients. Only on the first day, patients with CD had higher PI and lower CBFi compared to those without CD (2.2 ± 0.7 vs. 1.4 ± 0.5, p = 0.02; 363 ± 170 vs. 499 ± 133, p = 0.03, respectively). Multivariable analysis revealed delirium, but not PI, as an independent prognostic factor for CD (OR: 29.62, 95%CI 1.91–458.01, p = 0.01). Conclusion: Delirium, but not cerebral perfusion alterations, is an independent risk factor for cognitive impairment in septic patients who were discharged from the ICU.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The effect of high and low frequency cortical stimulation with a fixed or a Poisson distributed interpulse interval on cortical excitability in rats

Neurostimulation is a promising treatment for refractory epilepsy. We studied the effect of cortical stimulation with different parameters in the rat motor cortex stimulation model. High intensity simulation (threshold for motor response - 100 mu A), high frequency (130 Hz) stimulation during 1 h decreased cortical excitability, irrespective of the interpulse interval used (fixed or Poisson distributed). Low intensity (10 mu A) and/or low frequency (5Hz) stimulation had no effect. Cortical stimulation appears promising for the treatment of neocortical epilepsy if frequency and intensity are high enough