Cognitive training improves the disturbed behavioral architecture of schizophrenia-like rats, "Wisket".

Translational schizophrenia research depends on the relevance of animal models supported by reliable tests. Human data suggest that the intensive cognitive training in schizophrenia improves the memory impairments and decreases the chance of acute psychiatric remission. Here we examined the effects of a 10-day long training session in the behavioral architecture of a new schizophrenia-like rat substrain (Wisket) in a narrow square corridor with food rewards (AMBITUS). The instrument was designed to model the natural environment of rats and enable the simultaneous recording of multiple behavioral parameters. For the compact visualization of differences between the Wisket and control animals in several parameters (behavioromics), color-coded grid plots were applied. The Wisket animals exhibited an altered pattern and/or amount of locomotion, exploratory and food collecting activity at the first few days, revealing impaired motivation, attention, anxiety and learning ability (face validity). Most of the parameters normalized with training, except for the decreased exploratory activity. This resembles the effects of cognitive behavioral therapy in human schizophrenics providing a significant support for the predictive validity of this substrain as an animal model of schizophrenia. This study also highlights the importance of behavior tests that investigate the egocentric learning ability during reward-based tasks.

An Opto-Electronic Sensor for Detecting Soil Microarthropods and Estimating Their Size in Field Conditions.

Methods to estimate density of soil-dwelling arthropods efficiently, accurately and continuously are critical for investigating soil biological activity and evaluating soil management practices. Soil-dwelling arthropods are currently monitored manually. This method is invasive, and time- and labor-consuming. Here we describe an infrared opto-electronic sensor for detection of soil microarthropods in the size range of 0.4-10 mm. The sensor is built in a novel microarthropod trap designed for field conditions. It allows automated, on-line, in situ detection and body length estimation of soil microarthropods. In the opto-electronic sensor the light source is an infrared LED. Two plano-convex optical lenses are placed along the virtual optical axis. One lens on the receiver side is placed between the observation space at 0.5-1 times its focal length from the sensor, and another emitter side lens is placed between the observation space and the light source in the same way. This paper describes the setup and operating mechanism of the sensor and the control unit, and through basic tests it demonstrates its potential in automated detection of soil microarthropods. The sensor may be used for monitoring activities, especially for remote observation activities in soil and insect ecology or pest control.

In vivo potency of different ligands on voltage-gated sodium channels.

The Ranvier nodes of thick myelinated nerve fibers contain almost exclusively voltage-gated sodium channels (Navs), while the unmyelinated fibers have several receptors (e.g., cannabinoid, transient receptor potential vanilloid receptor 1), too. Therefore, a nerve which contains only motor fibers can be an appropriate in vivo model for selective influence of Navs. The goals were to evaluate the potency of local anesthetic drugs on such a nerve in vivo; furthermore, to investigate the effects of ligands with different structures (arachidonic acid, anandamide, capsaicin and nisoxetine) that were proved to inhibit Navs in vitro with antinociceptive properties. The marginal mandibular branch of the facial nerve was explored in anesthetized Wistar rats; after its stimulation, the electrical activity of the vibrissae muscles was registered following the perineural injection of different drugs. Lidocaine, bupivacaine and ropivacaine evoked dose-dependent decrease in electromyographic activity, i.e., lidocaine had lower potency than bupivacaine or ropivacaine. QX-314 did not cause any effect by itself, but its co-application with lidocaine produced a prolonged inhibition. Nisoxetine had a very low potency. While anandamide and capsaicin in high doses caused about 50% decrease in the amplitude of action potential, arachidonic acid did not influence the responses. We proved that the classical local anesthetics have high potency on motor nerves, suggesting that this method might be a reliable model for selective targeting of Navs in vivo circumstances. It is proposed that the effects of these endogenous lipids and capsaicin on sensory fibers are not primarily mediated by Navs.

[Combined use of pattern electroretinography and pattern visual evoked potentials in neuroophthalmological practice]. / A mintaváltás-ingerléssel kiváltott elektroretinogram és a látókérgi kiváltott válasz együttes használata a neurooftalmológiai gyakorlatban.

OBJECTIVE: To survey the role of pattern electroretinography (PERG) and pattern visual evoked potentials (VEPs) in the process of clinical evaluation of neuro-ophthalmological cases. The study is illustrated with the electrophysiological findings of 231 patients sent to our laboratory in 2005 because of the suspicion of damage in the optic pathway. METHODS: The RETIport program of the ROLAND equipment (Wiesbaden-Germany) was used to record PERGs and VEPs. The recordings were done according to the recommendations of the International Society for Clinical Electrophysiology of Vision. RESULTS: The combined application of PERG and VEP provided useful data on the retino-cortical conduction time and hence demyelinisation. The comparison of the N35/P50 and P50/N90 amplitudes of the PERG recordings greatly promoted the diagnostic procedure. CONCLUSIONS: The combined application of PERG and VEP methods is recommended in the assessment of optic nerve function of neuro-ophthalmological patients.