TIME STRUCTURE OF SELF-GROOMING IN THE RAT - SELF-FACILITATION AND EFFECTS OF HYPOTHALAMIC-STIMULATION AND NEUROPEPTIDES

Specific brain manipulations, such as stimulation of the paraventricul ar nucleus of the hypothalamus (PVH) or injections of neuropeptides, i ncrease self-grooming in the rat. Such manipulations also affect the d ifferent movements that constitute grooming. Using models to assess th e time structure of these movements, the authors demonstrate that the rules that control the time structure within grooming are different fr om the ones that control its initiation. This study also showed that g rooming is self-facilitating and that different brain manipulations in the same hypothalamic area induce structurally different kinds of gro oming. The authors suggest that this part of the hypothalamus is not o nly involved in setting priorities to grooming, relative to other beha viors, but is also involved in the timing of different grooming compon ents. These findings suggest that different neural mechanisms may be i nvolved in the initiation and internal time structure of grooming.