RESUMEN
The segmental and regional projections of the sciatic, tibial and common peroneal nerves to the substantia gelatinosa of spinal cord in rats were studied with the acid phosphatase method. Experiments were carried on 42 rats. Under chloral hydrate anesthesia, sciatic, tibial and common peroneal nerves were severed respecively. Then, after a survival time of 5～12 days, the lumbosacral segments of the spinal cord were removed and sectioned. The frozen sections were incubated with the modified Gomori's method.The projections of the sciatic and tibial nerves to the substantia gelatinosa (SG)were found in L_2～S_1, while these of the common peroneal nerve in L_(2～6).The projections of the sciatic nerve were found in the most medial, the intermediate and the most lateral parts of SG in the segments L_(2～3), and in entire SG in the segments L_4～S_1.The projections of the tibial nerve were shown in the most medial and the intermediate parts of SG in the segments L_(2～5), and in the medial parts of SG at L_6～S_1.The projections of the common peroneal nerve were found in the intermediate parts of SG in all segments L_(2～6).The above study has provided anatomical data for probing into the mechanism of somatosplanchnic interrelations and the principle governing acupuncture anesthesia.
RESUMEN
The afferent projections to the head of the caudate nucleus of rat from subcortical nuclei were studied with the method of retrograde axonal transport of horseradish peroxidase (HRP). Experiment were carried out in a series of adult rat. Under pentobarbital sodium anesthesia, 0.2～0.5,?l of 50% solution of HRP was injected slowly into the head of the caudate nucleus of the rat. according to the stereotaxic atlas by Massopust, Jr. After a survival time of 6～72 h, the animals were perfused with fixative solution (1.25% glutaraldehyde and 2.0% paraformaldehyde in 0.1M phosphate buffer, at pH 7.4). The brain was removed and then postfixed in same fixative at 4℃ for 6～18h. The frozen sections were incubated in a medium containing 3, 3′-diaminobenzidine tetrahydrochloride and hydrogen peroxide. The sections were examined microscopically under both bright-field and dark-field illumination. Labelled neurons were found ipsilaterally in the parafascicular nucleus of the thalamus and substantia nigra of the midbrain. They were also found in the dorsal nucleus of the midbrain raphe, mainly ipsilaterally, scantily contralaterally. Statistical examination showed as follows: The substantia nigra of the midbrain has the most labelled neurons, the dorsal nucleus of the midbrain raphe has the least labelled neurons, while the parafascicular nucleus of the thalamus has moderate number of labelled neurons. The afferent projections to the head of the caudate nucleus of the rat from the subcortical nuclei may play the role in the mechanism of pain and pain control.
RESUMEN
The normal structure of axonal terminals in lamina V of cervical spinal cordof the adult rat was examined with EM.Among 4039 various types of terminals inlamina V,the terminals with clear round synaptic vesicles(R)and the terminalswith clear flat synaptic vesicles(F)constitute about 40% each,the terminals withlarge granular vesicles(LG)about 16% and the central terminals of syntapticglomeruli about 3%.In addition,about 3.2% of the various types of terminalscontain neurofilaments,about 0.9% exhibit low electron dense axoplasm and thevesicles are partly lost or clumping.The synapses of the terminals in lamina V aremainly axodendritic,a small number of them are axoaxonal.There are more F,fewer R and LG in lamina V than those in lamina Ⅱ;thesynapses between the terminals and proximal dendrites,and axosomatic synapses aremore commonly seen in lamina V than in Ⅱ.