IN-VITRO THERMOSENSITIVITY OF THE MIDLINE THALAMUS

This study compared the thermosensitivity and spontaneous activity of thalamic midline neurons with those of neurons in areas widely regarde d to be involved in thermoregulation (preoptic/anterior hypothalamus a nd posterior hypothalamus). In vitro single unit recordings were made from neurons within the thalamic midline nuclei, the preoptic/anterior hypothalamus and posterior hypothalamus prior to and during a tempera ture change 3-7 degrees C above and below 37 degrees C. There were no significant differences in the degree of thermosensitivity or the prop ortion of thermosensitive neurons in the three areas. In each area exa mined, the thermosensitive neurons had a spontaneous activity which wa s significantly greater than that of the temperature-insensitive neuro ns. The results suggest that structures of the midline thalamus may pl ay a role similar to that of the preoptic/anterior hypothalamus and po sterior hypothalamus in the processing of temperature related informat ion.