Cholinergic control of striatal GABAergic microcircuits.

Cholinergic interneurons (CINs) are essential elements of striatal circuits and functions. Although acetylcholine signaling via muscarinic receptors (mAChRs) has been well studied, more recent data indicate that postsynaptic nicotinic receptors (nAChRs) located on striatal GABAergic interneurons (GINs) are equally critical. One example is that CIN stimulation induces large disynaptic inhibition of striatal projection neurons (SPNs) mediated by nAChR activation of GINs. Although these circuits are ideally positioned to modulate striatal output, the neurons involved are not definitively identified because of an incomplete mapping of CINs-GINs interconnections. Here, we show that CINs modulate four GINs populations via an intricate mechanism involving co-activation of presynaptic and postsynaptic mAChRs and nAChRs. Using optogenetics, we demonstrate the participation of tyrosine hydroxylase-expressing GINs in the disynaptic inhibition of SPNs via heterotypic electrical coupling with neurogliaform interneurons. Altogether, our results highlight the importance of CINs in regulating GINs microcircuits via complex synaptic/heterosynaptic mechanisms.

The differential effects of brief environmental enrichment following social isolation in rats.

Environmental enrichment (EE) in rodents is associated with a wide range of physiological, affective, and cognitive benefits. A seemingly opposite housing condition, social isolation (SI), is used as a rodent model of stress, negatively affecting several neurobiological mechanisms and hampering cognitive performance. Experimental designs that involve switching between these housing conditions produced mixed results. We evaluated different behavioral and cognitive effects of brief EE following long-term, SI-induced stress. We revealed the influence of enrichment after 30 days of isolation on behavioral despair, anxiety-like behavior, and spatial working memory in adult male Wistar rats and found a substantial anxiolytic effect in the experimental (SI to EE) group. Interestingly, rats exposed to EE also showed increased behavioral despair compared with the control (continuous SI) group. There was no difference in spatial working memory performance at the end of a 5-day water Y-maze (WYM) test. However, the SI to EE animals displayed better memory performance in the first 2 days of the WYM, indicating faster learning. In line with this difference, we recorded significantly more c-Fos-immunopositive (c-Fos+) cells in the retrosplenial and perirhinal cortices of the SI to EE animals. The lateral and basolateral nuclei of the amygdala showed no such difference. These results suggest that brief enrichment following isolation stress leads to differential results in affective and cognitive systems.

Vascular imaging findings with high-pitch low-dose dual-source CT in atypical Kawasaki disease.

PURPOSE: Determining the presence of aneurysms, thrombosis, and stenosis is very important for the diagnosis of atypical Kawasaki disease (AKD) and in the follow-up of AKD patients with aneurysms. We aimed to demonstrate high-pitch low-dose dual-source computed tomography (CT) angiography findings in pediatric patients with AKD. METHODS: Over a 5-year period, high-pitch low-dose CT angiography was performed to determine vascular aneurysms or occlusions in 17 patients who had suspected AKD. The patients ranged from 2 months of age to 11.3 years, with a mean age of 3 years. The American Heart Association's criteria were used to diagnose AKD. RESULTS: We did not detect any vascular problems in 6 of the patients, and they were not included in our study. Arterial aneurysms were present in 11 patients (aged 2 months to 11.3 years; mean age, 4.2 years; 7 males). In one patient, there was also a thrombus at an arterial aneurysm. Coronary artery aneurysms were detected in 7 patients and systemic artery aneurysms were detected in 7 patients. Three patients had both systemic and coronary aneurysms. CONCLUSION: Our results suggest that high-pitch low-dose dual-source CT can detect all types of aneurysms, stenosis and occlusions of vessels in patients with AKD who were not previously diagnosed. This useful, easy, robust and fast technique may be preferred to diagnose AKD.

Heavy metal contamination in street dusts and soils under different land uses in a major river basin in an urbanized zone of Aegean region, Turkey.

BACKGROUND: Meles River is one of the major Zn, Cr, Cu, Ni and Pb sources that enter Izmir inner Bay. However, the impacts of land uses on the river's catchment basin has not been investigated before. The study aims to exhibit the impacts of various land uses located on the catchment basin of the river. Cr, Cu, Pb, Ni and Zn concentrations were determined to present the current situation. In addition, the correlation analyses were performed in order to identify the metals' possible sources in the city. METHODS: Soils and street dusts from the sites representing industrial, residential, and commercial areas and the roads in Meles River basin were sampled and heavy metal levels were determined by using the aqua regia digestion. The correlations among the analytical parameters and the factors loaded with clusters of parameters identified by Principal Component Analysis were used to describe the major sources of studied elements The contamination assessment was also done by using the geoaccumulation index (I geo ) and enrichment factor (EF) values. RESULTS: Ni concentrations (average 697 mg kg-1) in soils were higher than the levels in street dusts (average 548 mg kg-1). Dust samples contained 131 mg kg-1 Pb, 179 mg kg-1 Cr, 347 mg kg-1 Cu, and 241 mg kg-1 Zn, while the average values of these metals were detected in lower levels in soils. The average values were found as 114 mg kg-1, 125 mg kg-1, 143 mg kg-1, and 129 mg kg-1, for Pb, Cr, Cu and Zn, respectively. The main component of soil heavy metals was determined as geochemical background enriched with long-term industrial depositions. Similarly, industrial emissions were found to be the major influence on the heavy metal levels in street dusts. CONCLUSIONS: Soil and street dust heavy metal levels are significantly affected by emissions from intense industrial activities and traffic emissions, and heavy metals are transported between these two matrices by exchanging masses between each other.