Selection of Neuroprotective Therapy in Patients with Chronic Cerebral Ischemia Taking Account of the Synergism of Drug Interactions

Neuroscience and Behavioral Physiology - Objective. To optimize selection of neuroprotective treatment protocols in patients with chronic cerebral ischemia taking account of synergism in drug...     

The adequacy of patient protection from surgical trauma under spinal anesthesia

Efficiency of various methods of anesthesia in prevention of the CNS segmented structures hyperreactivity induced by surgical trauma ware studied in 554 patients during planned orthopedic operations and operations on the pelvic organs. Spinal anesthesia played the crucial role in prevention of induced hyperreactivity of nociceptive neurons of the posterior spinal horns. A notable alleviation of postoperative pain in patients operated on under spinal anesthesia was a clinical confirmation of this fact. Analysis of the time course of the amplitudes of the control and test H-reflexes before and after the intervention showed that spinal anesthesia largely prevented perioperative changes in the spinal neuromotor stimulation and, from this viewpoint, can be regarded as the optimal method of anesthesia in surgery on the lower part of the trunk.     

Biorhythmologic Aspects of Seizure Activity

Seasonal and circadian rhythms of neuronal and organism resistance to convulsive effect of strychnine and penicillin were studied in vivo on mice and rats and in vitro on cultured mouse cerebellar sections. Resistance was assessed by the latency of seizures in mice and neuronal response to convulsants in sections. In the night and morning time (0:00-9:00) seizure resistance in mice increased: it manifested in longer latency and lower mortality compared to those in the day and evening time (12:00-21:00). Seizure resistance was minimum in autumn and maximum in winter. Neurons in cerebellar section were most resistant to the convulsive effect of penicillin in autumn and winter and least resistant in spring and summer. Circadian rhythms of cerebellar neuron resistance to convulsants were opposite, which attests to reciprocal relations between epileptogenic and antiepileptic (cerebellar) cerebral structures.     

Antihypoxic properties of opiates and substance P

Using survival slices of the rat cerebellum, we studied the influence of opiates (alpha- and beta-endorphines, met-enkephalines) as well as substance P (SP) on the impulse activity (IA) of neurons. Low doses of the studied substances (10(-8)-10(-10) M) for the most part increased the IA of the neurons, while high doses (10(6)-10(-5) M) produced biphasic reaction (inhibition-excitation). It is supposed that opiates and SP act as transmitters in the cerebellum. Under increasing hypoxia, opiates and SP manifested antixypoxic properties both in low O22 concentration and under reoxygenation. Opiates and SP proved to be natural antihypoxants involved not only in nociception mechanisms but also in brain adaptation to oxygen deficiency.