Action of the "delta-sleep peptide" on monoamine oxidase and acetylcholinesterase activity in subcellular fractions from different rabbit brain formations in vivo

Administration of delta-sleep-inducing peptide (DSIP) in vivo in a dose of 30 microgram/kg bw brings about MAO-A (substrate-serotonin) activation in synaptosome subfractions and cellular mitochondria from the brain structures (motor cortex, nucleus caudatus, thalamus). Activity of MAO-B (substrate-p-nitrophenylethylamine) and acetylcholinesterase was inhibited negligibly and specifically in subcellular fractions of the test brain structures. The results suggest that DSIP effects the regulatory or modulation function in the synapse. As one of the elements of sleep mechanisms this peptide induces a number of processes, particularly in serotonin metabolism.     

The neurochemical and behavioral indices of an acquired alcohol craving in rats under conditions of information loading]

The state of neurotransmitter systems was studied in the groups of Wistar rats discriminated by striving for alcohol and rejecting it after the information load (alimentary instrumental conditioning in a labyrinth). The specific activities of neurotransmitter metabolizing enzymes (MAO A and B, acetylcholinesterase, and acetylcholinetransferase) and the content of biogenic amines and their metabolites (serotonin, 5-hydroxyindoleacetic acid, noradrenaline, and dopamine) were measured in homogenates and subfractions of sensorimotor cortex and caudate nucleus. It was found out that the biochemical indices correlated with cognitive abilities of animals. Stress-resistant rats, which were capable for acquisition of the complex skill, refused alcohol after the information load and were characterized by activation of the brain neurotransmitter systems. The rats, which were unable to fulfill the cognitive task, began to abuse alcohol and were characterized by suppression of the neurotransmitter systems. It seems possible that the brain neurotransmitter metabolism adequately reflects the characteristics of the higher nervous activity of animals and their resistance to alcohol.     

Mechanism of the action of the delta sleep-inducing peptide against a background of L-DOPA administration

A reciprocal nature of the shifts in activity of type A and B monoamine oxidases has been observed under the effect of DSIP against the background of L-DOPA administration (50 micrograms/kg) in the subfractions from the rabbit sensorimotor cortex. The results suggest that the activation of type A monoamine oxidase and serotoninergic system is the basis of the adaptive behavior of animals.     

Changes in the functional parameters of the brain structures under the influence of enkephalin-like tetrapeptidamide

In complex neurophysiological and cytobiochemical study single injections of tetrapeptide amide (TPA) caused a short-term analgetic effect which manifested itself in the absence of motor reactions and EEG changes of cortical and subcortical brain structures after painful stimulation of extremities. This effect was accompanied by changes of some indices of transmitter (monoamine oxidase) and protein metabolism in the cerebral hemispheres at cellular and subcellular levels. In 30-40 min after a TPA injection, EEG suppression and absence of EPs to light flashes were observed in cortical and subcortical structures. Simultaneously motor disorders developed. The observed EEG changes had an undulatory character: on the second day EEGs were restored and on the third day--suppressed once again. This period of TPA action was accompanied by varied changes of the investigated types of metabolism. The question of the necessity of systemic approach to the study of TPA action is discussed, as such an approach allows to reveal complex neurophysiological and fine biochemical relations in the reactions of brain structures and in animal behaviour.     

Effect ot tuftsin on cerebral monoamine oxidase and acetylcholinesterase activity

The administration of a tetrapeptide tuftsin at a dose of 300 mkg/kg body weight for 30, 75 min or 3 days leads to the changes in specific activity of monoamine oxidase, forms A and B, and acetylcholinesterase in synaptosomal and cellular mitochondrial subfractions from the rabbit sensorimotor cortex and nucleus caudatus. The reciprocity of neuro-transmitter systems and specific peptide effects on the brain structures have been demonstrated. The results suggest that tuftsin has an activating effect on dopamine metabolism.     

Bioelectrical activity and neuromediator metabolism in different brain structures during chronic haloperidol administration]

First haloperidol administration is followed by the reorganization of evoked potentials in visual cortex. During haloperidol administration (10-12 days after the beginning) variations of evoked potentials is visual cortex and in subcortical structures uniform evoked potentials took place.