Premium
Distribution and brainstem origin of cholecystokinin‐like immunoreactivity in the opossum cerebellum
Author(s) -
King James S.,
Bishop Georgia A.
Publication year - 1990
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.902980309
Subject(s) - nucleus , anatomy , serotonergic cell groups , biology , cerebellum , vestibular nuclei , cerebellar cortex , reticular formation , lateral reticular nucleus , reticular connective tissue , flocculus , mossy fiber (hippocampus) , parabrachial nucleus , lateral vestibular nucleus , medulla oblongata , brainstem , neuroscience , central nervous system , dentate gyrus , biochemistry , receptor , serotonergic , serotonin
In order to determine the distribution of the peptide cholecystokinin (CCK) within the cerebellum and medullary precerebellar nuclei of the adult opossum, sections of these brain regions were processed for peroxidase‐antiperoxidase immunohistochemistry. Within the inferior and superior cerebellar peduncles, fine‐beaded fibers are evident and a beaded plexus of fibers is present in all the cerebellar nuclei. In the overlying cerebellar cortex, CCK‐positive mossy fiber rosettes are present in all lobules, where their morphology varies from simple enlargements to more complex rosettes. However, their distribution varies particularly in vermal lobules II, III, VII, and IX where they are organized in parasagittal bands. Climbing fibers that are positive for CCK are present in very restricted areas of vermal lobules IV, VII, and VIII. After colchicine pretreatment, CCK‐positive cell bodies are seen in restricted regions of the posterior interposed and fastigial nuclei as well as within several precerebellar nuclei known to give rise to mossy fibers. Such nuclei include the lateral cuneate nucleus, the nucleus prepositis hypoglossi, the nucleus reticularis latefalis, the nucleus raphe obscurus, the paramedian reticular nucleus, the nucleus reticularis gigantocellularis, and the medial vestibular nucleus. To localize the brainstem origin(s) of the CCK fibers in the cerebellum, a double‐label paradigm employing a retrograde tracer and CCK immunohistochemistry was used. These experiments indicate that CCK mossy fibers originate primarily within the lateral cuneate nucleus, the perihypoglossal complex, and the lateral reticular nucleus. Some also originate within the medial vestibular nucleus and the nucleus reticularis gigantocellularis. In addition, double‐labeled cell bodies are present within the caudal medial accessory inferior olive, the likely source of the CCK‐positive climbing fibers. These data indicate that specific populations of climbing fibers and mossy fibers may utilize CCK to alter the firing rate of their target neurons.