[Neuronal responses of the intact cortex and isolated strips of the sensorimotor cortex to systemic administration of thyroxine].

The pattern of neuronal responses to alterations in hormonal homeostasis was specified. A study was made of neuronal responses of intact and neuronally isolated strips of the sensorimotor cortex (ISC) to intravenous injection of thyroxine. The neuronal response of the ISC was found to differ substantially from the response of intact cortical neurons. Less percentage of the responding neurons was registered in the ISC. The responses were considerably shortened, while the neurons discharged at a lower frequency. The differences indicate that, as compared to subcortical structures, the cortical neurons are less susceptible to blood hormones. It is emphasized that subcortical structures, particularly the hypothalamus are of major importance for transmission of hormonal influences to the brain cortex.