The transfer of bacterial biotin genes to Escherichia coli K-12 cells by transfection with lambda bio phage DNA.

The transfection of biotin genes to biotin negative Escherichia coli K-12 cells with donor DNA isolated from transducing lambda bio phages was examined. The transfection of the cells was performed in the presence of bovine serum albumin and sucrose (Osowiecki and Skalińska, 1974).     

The effect of intracerebroventricular administration of substance P fragment and met-enkephalin on the transmission of nervous impulses between the midbrain reticular formation and two generators of the hippocampal theta rhythm in rabbits

The effect of intracerebroventricular administration of Substance P fragment and met-enkephalin on the excitability of two generators of hippocampal theta rhythm was investigated in the experiments performed on chronic rabbits. Substance P had a strong facilitatory effect on the threshold of the generator of the hippocampal theta rhythm of the frequency 4-7 c/s and an inhibitory effect on the threshold of the generator of the 7-12 c/s frequency evoked by stimulation of the midbrain reticular formation. These effects were dose dependent. The effects of met-enkephalin were opposite. They increased the threshold of the 4-7 c/s hippocampal generator and decreased the threshold of the other generator. The effect of these two compounds was evaluated according to the energy of electrical trains of pulses maintaining the continuous arousal pattern in the hippocampus.