Effects of Corticoliberin on Synaptic Transmission in Rat Olfactory Cortex Slices in a Water Immersion Model of Depression

摘要

Corticoliberin (corticotrophin-releasing factor, CRF, CRH) is an active regulator of endocrine, autonom-ic, and immune functions in stress, as well as a mediator of anxiety, determining the behavioral stressresponse. The present report describes studies of its action on neuron activity evoked by microstimulationof olfactory cortex slices. Behavioral testing in a T maze was used to select individuals with a passivebehavioral strategy from a population of Wistar rats, and the animals were subjected to water immersion.Olfactory cortex slices were prepared 10 days later and evoked focal potentials were recorded on perfu-sion with medium containing corticoliberin (0.1 μM). Among active rats, 60% of slices retained highexcitability after stress, and corticoliberin produced only insignificant reductions in the amplitudes ofexcitatory potentials in these slices, simultaneously increasing the amplitudes of inhibitory potentials.Low excitability was found in 40% of slices from active stressed rats, and corticoliberin had a significantinhibitory effect in these slices. Addition of corticoliberin to the incubation medium used for slices frompassive rats with initially low excitability led to complete blockade of synaptic transmission. These datasupport the involvement of corticoliberin in the development of depression.