[Comparative analysis of single central nervous system neuron sensitivity to thyrotropin-releasing hormone and its...

Sensitivity of the cortex single neurons, hippocamp, thalamus medial nucleus, periventricular and arcuate hypothalamus nuclei to the thyrotropin-releasing hormone (TRH) and its structural analog (Pyr-Ser-Leu-NH2) under conditions of their microionophoretic application by means of multichannel microelectrodes was studied and compared in experiments on rats. There was no significant similarity between TRH and its analog effects in all the test brain regions with the exception of the cortex. A significant positive correlation between their influence on the single neuron activity was recorded. However, the sensitivity to the cortex cell analog was less pronounced. The largest amount of TRH irresponsive cells were seen in the thalamus medial nucleus neurons. On the contrary, their sensitivity to the TRH analog was comparatively high.