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Intra-axonal recording and horseradish peroxidase (HRP) injection techniques were employed to define the response properties of low-threshold mechanoreceptive periodontal afferents and of the tooth pulp afferents and the morphological characteristics of their axon arbors in the nucleus principalis (Vp) and rostrodorsomedial (Vo.r) and dorsomedial parts (Vo.dm) of the nucleus oralis (Vo). The central terminals of 3 fast adapting (FA) and 4 slowly adapting (SA) periodontal afferents and 4 tooth pulp (TP) afferents were recovered for detailed analyses. Stained axons in the trigeminal sensory tract ascended and descended (bifurcating fibers), or descended without bifurcation (descending non-bifurcating fibers). The ratio of the bifurcating fibers to the descending non-bifurcating fibers was about three to one for each type of afferents. The main collaterals given off from the ascending branches terminated in the Vp. Most collaterals given off from the descending branches terminated in the Vo with the exception of few instances. In case of the FA afferents, the ascending branches gave off all main collaterals into the Vp with rostrocaudal and dorsoventral continuities in their arbors, whereas the descending branches gave off all main collaterals, except two collaterals, into the Vo with rostrocaudal discontinuities. The projections from the FA afferents to the Vo.dm was predominant in terms of the number of boutons and the length of preterminal and terminal branches. In case of the SA afferents, the collaterals from the ascending and descending branches formed rostrocaudally and dorsoventrally discontinuous terminal arbors. In terms of the density of boutons the SA afferents were divided into two subtypes. One had a preferential projection into the Vp or Vo, whereas others lacked a selective projection. In case of the TP afferents, the main collaterals of the ascending branches formed partially overlapping terminal arbors, but the terminal arbors formed by the collateral of the descending branches did not overlap. The frequency of collaterals of the TP afferents was less than that of the other types of afferents. The terminal arbors including the density of boutons of the pulpal afferents were less extensive than those of the other types of afferents. The average size of varicosities became smaller in the following subdivisions. Vp, Vo.r and Vo.dm for SA and TP afferents. The size of varicosities of the TP afferents was smaller and that of the FA afferents was larger than that of the SA afferents.(ABSTRACT TRUNCATED AT 400 WORDS)
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
February 1994,
The Journal of comparative neurology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
June 1975,
Brain research,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
January 1973,
Acta neurobiologiae experimentalis,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
July 1987,
The Journal of comparative neurology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
February 1993,
Journal of neurophysiology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
September 1978,
The Journal of physiology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
February 1986,
The Journal of comparative neurology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
January 1980,
Experimental brain research,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
June 1998,
The Journal of comparative neurology,
K Tsuru, and
K Otani, and
K Kajiyama, and
S Suemune, and
Y Shigenaga
October 1976,
The Journal of physiology,
