Projections of ventromedial hypothalamic neurons to the midbrain central gray: an ultrastructural study.

摘要: Ventromedial hypothalamic projections to the midbrain central gray may be involved in mediation of female reproductive behavior. In order demonstrate and examine ventromedial nucleus gray, rat, electrolytic lesions were placed was examined for ultrastructural signs degeneration at various intervals, i.e. 27.5 h two, four, six eight days following lesions. The fine structure unlesioned animals also characterize its normal morphology establish a baseline with which compare effects lesion. animals, neuropil contained several synaptic types, axodendritic synapses appearing most predominant. Dendrites well-preserved microtubules. Synaptic endings many clear, round vesicles some dense-cored as well. Neuropil both asymmetric symmetric. Cell bodies characterized by light cytoplasm had symmetric on their surface. Following nucleus, types degenerative patterns seen including electron-dense, flocculent, watery, pinocytotic degeneration. Specific characteristics included shrunken, dense axons endings, clumped vesicles, abnormally large, dark mitochondria, membranous sacs sizes, swollen reduced numbers processes containing large coated vesicles. Some these already evident addition, degenerating postsynaptic cell gray. At survival time, dendritic often appeared swollen, devoid microtubules, enlarged mitochondria. longer times neuronal observed electron-dense pycnotic nuclei. Both pre- elements engulfed glial processes. Control non-hypothalamic regions project gigantocellularis pontine reticular formation non-projecting region, parietal cortex, performed.(ABSTRACT TRUNCATED AT 400 WORDS)