Circadian Behavioral Responses to Light and Optic Chiasm-Evoked Glutamatergic EPSCs in the Suprachiasmatic Nucleus of ipRGC Conditional vGlut2 Knock-Out Mice

Intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN), a circadian oscillator that functions as a biological clock. ipRGCs use vesicular glutamate transporter 2 (vGlut2) to package glutamate into synaptic vesicles and light-evoked resetting of the SCN circadian clock is widely attributed to ipRGC glutamatergic neurotransmission. Pituitary adenylate cyclase-activating polypeptide (PACAP) is also packaged into vesicles in ipRGCs and PACAP may be coreleased with glutamate in the SCN. vGlut2 has been conditionally deleted in ipRGCs in mice [conditional knock-outs (cKOs)] and their aberrant photoentrainment and residual attenuated light responses have been ascribed to ipRGC PACAP release. However, there is no direct evidence that all ipRGC glutamatergic neurotransmission is eliminated in vGlut2 cKOs. Here, we examined two lines of ipRGC vGlut2 cKO mice for SCN-mediated behavioral responses under several lighting conditions and for ipRGC glutamatergic neurotransmission in the SCN. Circadian behavioral responses varied from a very limited response to light to near normal photoentrainment. After collecting behavioral data, hypothalamic slices were prepared and evoked EPSCs (eEPSCs) were recorded from SCN neurons by stimulating the optic chiasm. In cKOs, glutamatergic eEPSCs were recorded and all eEPSC parameters examined (stimulus threshold, amplitude, rise time or time-to-peak and stimulus strength to evoke a maximal response) were similar to controls. We conclude that a variable number but functionally significant percentage of ipRGCs in two vGlut2 cKO mouse lines continue to release glutamate. Thus, the residual SCN-mediated light responses in these cKO mouse lines cannot be attributed solely to ipRGC PACAP release

The experience of levetiracetam (keppra) application for the treatment of pain syndromes in oncologic patients on the background of chemotherapy and patients with facial neuralgia

Antiepileptic preparation Levetiracetam (Keppra) possesses minimal medicinal interaction with other drugs which are used for epileptic patients with severe concomitant diseases. We have studied Levetiracepam efficacy in patients with tumours of various localization, with marked pain syndrome generalized after a complex treatment (operative, radiation) on the background of chemotherapy. The second group included the patients with facial neuralgia. Analyzing the results of the preparation application we have determined that Levetiracetam is mostly effective with the dose of 2500-3000mg for 60-65old patients having metastases, with the dose reaching 2000mg per day for 70-80old patients having facial neuralgia.Противоэпилептический препарат леветирацетам (кеппра) обладает минимальным лекарственным взаимодействием с другими препаратами, которые применяются у больных эпилепсией с тяжелыми сопутствующими заболеваниями. Изучена эффективность леветирацетама у пациентов с различной локализацией опухолевого процесса, с выраженным болевым синдромом, генерализовавшимся после проведенного ранее комплексного лечения (оперативное, лучевое) на фоне химиотерапии. Вторую группу составили пациенты с невралгией тройничного нерва. Анализируя результаты применения препарата, установлено, что леветирацетам наиболее эффективен у больных с метастазами в 60-65 лет в дозе - 2500-3000 мг, с НТН в 70-80 лет при достижении дозы 2000 мг в сутки

Circadian Behavioral Responses to Light and Optic Chiasm-Evoked Glutamatergic EPSCs in the Suprachiasmatic Nucleus of ipRGC Conditional vGlut2 Knock-Out Mice

Intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN), a circadian oscillator that functions as a biological clock. ipRGCs use vesicular glutamate transporter 2 (vGlut2) to package glutamate into synaptic vesicles and light-evoked resetting of the SCN circadian clock is widely attributed to ipRGC glutamatergic neurotransmission. Pituitary adenylate cyclase-activating polypeptide (PACAP) is also packaged into vesicles in ipRGCs and PACAP may be coreleased with glutamate in the SCN. vGlut2 has been conditionally deleted in ipRGCs in mice [conditional knock-outs (cKOs)] and their aberrant photoentrainment and residual attenuated light responses have been ascribed to ipRGC PACAP release. However, there is no direct evidence that all ipRGC glutamatergic neurotransmission is eliminated in vGlut2 cKOs. Here, we examined two lines of ipRGC vGlut2 cKO mice for SCN-mediated behavioral responses under several lighting conditions and for ipRGC glutamatergic neurotransmission in the SCN. Circadian behavioral responses varied from a very limited response to light to near normal photoentrainment. After collecting behavioral data, hypothalamic slices were prepared and evoked EPSCs (eEPSCs) were recorded from SCN neurons by stimulating the optic chiasm. In cKOs, glutamatergic eEPSCs were recorded and all eEPSC parameters examined (stimulus threshold, amplitude, rise time or time-to-peak and stimulus strength to evoke a maximal response) were similar to controls. We conclude that a variable number but functionally significant percentage of ipRGCs in two vGlut2 cKO mouse lines continue to release glutamate. Thus, the residual SCN-mediated light responses in these cKO mouse lines cannot be attributed solely to ipRGC PACAP release

The transfer of 137Cs and 90Sr to dairy cattle fed fresh herbage collected 3.5 km from the Chernobyl nuclear power plant

A study conducted during summer 1993 to determine the bioavailability and transfer of 137Cs and 90Sr to dairycattle from herbagecollected from a pasture contaminated by particulate fallout is described. The study pasture was located 3.5km from the Chernobyl nuclear powerplant. The true absorption coefficient (At) determined for 137Cs (0.23) was considerably lower than previous estimates for radiocaesium incorporated into vegetation by root uptake. It is likely that the low dry matter digestibility of the diet and the potential presence of 137Cs associated with adherent soil-associated fuel particles contributed to this low bioavailability. The At value determined for 90Sr (0.27) did not indicate a reduced bioavailability. It is suggested that the current and previous calcium status of the animals was the controlling influence on the transfer of 90Sr from the diet to mil