Microelectrode Recording for Deep Brain Stimulation of the Subthalamic Nucleus in Patients with Advanced Parkinson's Disease:Advantage or Loss of Time?

AIM: To investigate the effect of using microelectrode recording (MER) on the length of time required to carry out a deep brain stimulation (DBS) procedure of the subthalamic nucleus in patients with Parkinson's disease (PD). MATERIAL and METHODS: The time required to include MER in the DBS operation was calculated for the first and second sides in 24 patients with PD. The number of microelectrodes used on each trajectory for the first and second sides, and the percentage of permanent electrodes implanted on each trajectory for the first and second sides, were quantified. RESULTS: The average times taken to use MER were 23.4 +/- 6.2 minutes, 17.4 +/- 6.5 minutes, and 41.2 +/- 6.3 minutes for the first side, second side and total procedure, respectively. In 75% of patients, the permanent electrode was implanted at the planned target site for the first side, and in 61% of patients for the second side. CONCLUSION: MER extends the time required to carry out the DBS procedure. However, during surgery, it provides real-time information on the electrodes' neurophysiological locations and helps the surgical team choose an alternative target if the planned target does not produce satisfying results

A remarkable new leaf-cutter bee from Thailand (Hymenoptera: Megachilidae)

This is the publisher's version, copyright by Akademie Verlag.A remarkable new species of leaf-cutter bee, Megachile trichorhytisma ENGEL sp. n., is described and figured from two males collected in northern Thailand. The species is placed in a new subgenus, Aethomegachile ENGEL & BAKER subgen. n., and is differentiated from previously known lineages of Megachile

The Connectivity Fingerprint of the Human Frontal Cortex, Subthalamic Nucleus, and Striatum

Within the cortico basal ganglia (BG)–thalamic network, the direct and indirect pathways comprise of projections from the cortex to the striatum (STR), whereas the hyperdirect pathway(s) consist of cortical projections toward the subthalamic nucleus (STN). Each pathway possesses a functionally distinct role for action selection. The current study quantified and compared the structural connectivity between 17 distinct cortical areas with the STN and STR using 7 Tesla diffusion weighted magnetic resonance imaging (dMRI) and resting-state functional MRI (rs-fMRI) in healthy young subjects. The selection of these cortical areas was based on a literature search focusing on animal tracer studies. The results indicate that, relative to other cortical areas, both the STN and STR showed markedly weaker structural connections to areas assumed to be essential for action inhibition such as the inferior frontal cortex pars opercularis. Additionally, the cortical connectivity fingerprint of the STN and STR indicated relatively strong connections to areas related to voluntary motor initiation such as the cingulate motor area and supplementary motor area. Overall the results indicated that the cortical–STN connections were sparser compared to the STR. There were two notable exceptions, namely for the orbitofrontal cortex and ventral medial prefrontal cortex, where a higher tract strength was found for the STN. These two areas are thought to be involved in reward processing and action bias

Required reserves as a credit policy tool

This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring them to hold real balances, and (iv) standard productivity and money growth shocks are two sources of aggregate uncertainty. We calibrate the model to the Turkish economy which is representative of using reserve requirements as a macroprudential policy tool recently. We also consider the impact of financial shocks that affect the net worth of financial intermediaries. We find that (i) the time-varying required reserve ratio rule countervails the negative effects of the financial accelerator mechanism triggered by adverse macroeconomic and financial shocks, (ii) in response to TFP and money growth shocks, countercyclical reserves policy reduces the volatilities of key real macroeconomic and financial variables compared to fixed reserves policy over the business cycle, and (iii) a time-varying reserve requirement policy is welfare superior to a fixed reserve requirement policy. The credit policy is most effective when the economy is hit by a financial shock. Time-varying required reserves policy reduces the intertemporal distortions created by the credit spreads at expense of generating higher inflation volatility, indicating an interesting trade-off between price stability and financial stability

Required reserves as a credit policy tool

This paper conducts a quantitative investigation of the role of reserve requirements as a macroprudential policy tool. We build a monetary DSGE model with a banking sector in which (i) an agency problem between households and banks leads to endogenous capital constraints for banks in obtaining funds from households, (ii) banks are subject to time-varying reserve requirements that countercyclically respond to expected credit growth, (iii) households face cash-in-advance constraints, requiring them to hold real balances, and (iv) standard productivity and money growth shocks are two sources of aggregate uncertainty. We calibrate the model to the Turkish economy which is representative of using reserve requirements as a macroprudential policy tool recently. We also consider the impact of financial shocks that affect the net worth of financial intermediaries. We find that (i) the time-varying required reserve ratio rule countervails the negative effects of the financial accelerator mechanism triggered by adverse macroeconomic and financial shocks, (ii) in response to TFP and money growth shocks, countercyclical reserves policy reduces the volatilities of key real macroeconomic and financial variables compared to fixed reserves policy over the business cycle, and (iii) a time-varying reserve requirement policy is welfare superior to a fixed reserve requirement policy. The credit policy is most effective when the economy is hit by a financial shock. Time-varying required reserves policy reduces the intertemporal distortions created by the credit spreads at expense of generating higher inflation volatility, indicating an interesting trade-off between price stability and financial stability

The Effects of Additional Monetary Tightening on Exchange Rates

Since the global financial crisis, Central Banks have used various policy tools to sustain financial stability besides price stability. Additional Monetary Tightening is one of these tools that the Central Bank of the Republic of Turkey used in 2011-2012. The effects of this tool on the exchange rate are the main theme of this paper. Our analysis indicates that additional monetary tightening has a significant role in reducing volatility in the exchange rate. It is also shown that during the days of additional tightening Turkish Lira appreciated against the emerging market currencies

The Effects of Additional Monetary Tightening on Exchange Rates

Since the global financial crisis, Central Banks have used various policy tools to sustain financial stability besides price stability. Additional Monetary Tightening is one of these tools that the Central Bank of the Republic of Turkey used in 2011-2012. The effects of this tool on the exchange rate are the main theme of this paper. Our analysis indicates that additional monetary tightening has a significant role in reducing volatility in the exchange rate. It is also shown that during the days of additional tightening Turkish Lira appreciated against the emerging market currencies

Effect of Anesthesia on Microelectrode Recordings During Deep Brain Stimulation Surgery:A Narrative Review

Deep brain stimulation (DBS) is an effective surgical treatment for patients with various neurological and psychiatric disorders. Clinical improvements rely on careful patient selection and accurate electrode placement. A common method for target localization is intraoperative microelectrode recording (MER). To facilitate MER, DBS surgery is traditionally performed under local or regional anesthesia. However, sedation or general anesthesia is sometimes needed for patients who are unable to tolerate the procedure fully awake because of severe motor symptoms, psychological distress, pain, or other forms of discomfort. The effect of anesthetic drugs on MER is controversial but likely depends on the type and dose of a particular anesthetic agent, underlying disease, and surgical target. In this narrative review, we provide an overview of the current literature on the anesthetic drugs most often used for sedation and anesthesia during DBS surgery, with a focus on their effects on MERs

Periaqueductal Grey Stimulation Induced Panic-Like Behaviour Is Accompanied by Deactivation of the Deep Cerebellar Nuclei

Until recently, the cerebellum was primarily considered to be a structure involved in motor behaviour. New anatomical and clinical evidence has shown that the cerebellum is also involved in higher cognitive functions and non-motor behavioural changes. Functional imaging in patients with anxiety disorders and in cholecystokinin tetrapeptide-induced panic-attacks shows activation changes in the cerebellum. Deep brain stimulation of the dorsolateral periaqueductal grey (dlPAG) and the ventromedial hypothalamus (VMH) in rats has been shown to induce escape behaviour, which mimics a panic attack in humans. We used this animal model to study the neuronal activation in the deep cerebellar nuclei (DCbN) using c-Fos immunohistochemistry. c-Fos expression in the DCbN decreased significantly after inducing escape behaviour by stimulation of the dlPAG and the VMH, indicating that the DCbN were deactivated. This study demonstrates that the DCbN are directly or indirectly involved in panic attacks. We suggest that the cerebellum plays a role in the selection of relevant information, and that deactivation of the cerebellar nuclei is required to allow inappropriate behaviour to occur, such as panic attacks