Altered Cortical Oscillations: Investigations into a Putative Neural Correlate of Tinnitus

Abnormal cortical oscillations have been implicated in tinnitus generation. To gain further insight into this relationship, we performed two Experimental Series, both employing behavioural, pharmacological, and in vivo electrophysiological techniques in an animal model. To that end, we revealed three novel findings: (1) While exposure to 250 mg/kg sodium salicylate or transient loud noise induced behavioural evidence of tinnitus, these insults caused dissimilar effects on spontaneous cortical oscillations; (2) Despite these dissimilar effects, sodium salicylate and loud noise exposure caused similar deficits in the evoked oscillatory activity elicited by the auditory steady state response; and (3) Manipulation of medial geniculate body GABAergic inhibition is sufficient to alter spontaneous cortical oscillations, but does not induce tinnitus-like behaviour. Collectively, these findings suggest that there is no clear link between altered cortical oscillations and tinnitus, and the 40 Hz ASSR might be a useful tool for assessing the presence of tinnitus in animals

In the footsteps of Alfred Werner: The institute of Inorganic Chemistry at the University of Zurich

Inorganic chemistry has a long-standing tradition at the University of Zurich starting with Carl Jacob Lowig, the first professor of chemistry. The influence of Nobel Prize winner Alfred Werner in coordination, organometallic, and bioinorganic chemistry extends right up to the present day as can be seen in many of the research fields of the current professors and young research scientists. With all due respect for the long tradition in inorganic chemistry the Institute of Inorganic Chemistry is also looking forwards to define its role to meet the challenges of the future

Absorption of femtosecond laser pulses in high-density plasma.

The absorption of 250-fs KrF laser pulses incident on solid targets of aluminum and gold has been measured as a function of polarization and angle of incidence for the intensity range of 1014–2.5×1015 W cm−2. Maximum absorption of over 60% occurs for p-polarized radiation at angles of incidence in the range of 48°–57°. The measured results are in agreement with absorption on a steep density gradient

The influence of liver dysfunction on cyclosporine pharmacokinetics -A comparison between 70 per cent hepatectomy and complete bile duct ligation in dogs-

The influence of experimentally induced hepatic dysfunction on the pharmacokinetics of Cyclosporine A (CsA) was determined in dogs. The pharmacokinetics of oral (PO) and intravenous (IV) CsA were studied before and after 70 per cent hepatectomy or complete bile duct ligation (CBDL). Changes in liver function were monitored by serial measurements of serum bilirubin, and by the maximum removal rate (Rmax) and plasma disappearance rate (ICG-K) of indocyanine green (ICG). Concentrations of CsA in whole blood were measured by HPLC. Seventy per cent hepatectomy caused significant liver dysfunction: the ICG-Rmax decreased by 47.7±7.1 per cent (mean±SD) and the ICG-K decreased by 61.3±9.7 per cent during the first week after hepatectomy. At the same time, the systemic clearance (CLs) of IV-CsA decreased by 43.9±8.2 per cent, the area under the concentration curve (AUC) of IV-CsA increased by 35.4±20.8 per cent and the bioavailability of CsA decreased by 26.4±14.8 per cent. CBDL also induced significant liver dysfunction: the ICG-Rmax decreased by 39.1±12.8 per cent and the ICG-K decreased by 65.6±3.6 per cent in the second week after the operation. During the same period, the AUC of PO-CsA decreased by 69.9±10.7 per cent and the bioavailability of CsA also decreased markedly by 73.9±15.6 per cent. These data indicate that hepatic impairment significantly influences the pharmacokinetics of CsA, not only by the changes in intestinal absorption, but also by those in hepatic, metabolism. Dose adjustment is therefore necessary in the presence of hepatic dysfunction in order to maintain an adequate blood concentration of CsA without causing side effects. © 1989 The Japan Surgical Society