OBJECTIVETo study the microsurgical anatomy of the posterior inferior cerebellar artery (PICA) for neurosurgery.

METHODSTwenty Chinese adult brain samples (40 sides) were measured with microscope for the diameters, lengths, origins, courses, and the branches of the PICA. The relationship between the PICA and cranial nerves was also checked.

RESULTSThere were 35 PICAs in 20 brain samples. The mean diameter of the PICAs was (1.6 +/- 0.6) mm, the mean length from PICAs' origin of vertebral artery to the vertebrobasilar junction was (16 +/- 5) mm. In 35 PICAs, 28 PICAs go through the rootlets of XII cranial nerves, 7 PICAs go through inferior XII cranial nerves, and 32 PICAs go through the rootlets of XI cranial nerves.

CONCLUSIONSPICA is an important branch artery with more variation and complex relationship to the cranial nerves trend in the vertebral artery system. It is necessary to master the microsurgical anatomy of PICA and to be careful protection during the neurosurgical operations.

Adult ; Carotid Artery, Common ; anatomy & histology ; Cerebellum ; blood supply ; Cerebral Arteries ; anatomy & histology ; Cranial Nerves ; anatomy & histology ; Humans ; Vertebral Artery ; anatomy & histology

The spicoreticulocerebellar (SRC) tract is an indirect spinocerebellar tract formed by the reticular formation (RF), which is connected to the cerebellum and spinal cord. The RF receives ascending fibers to both the spinal enlargement and sends descending fibers to the cerebellum. This study demonstrated that the connectivity of the neurons in the RF is concerned to the cerebellum and spinal cord using the anterograde projection with biotinylated dextran amine (BDA) and retrograde labeling with wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Until now, a preliminary study in mammals has dealt with the afferent and efferent pathways in separating groups of neurons in the RF. There are only few reports on chickens. This study examined the SRC tract in chickens. Following bilateral injections we injected BDA into chicken spinal cord (lumbosacral enlargement) and WGA-HRP into the cerebellum. Both of single- and double-labeled cells were found within the RF. The spinoreticular axons were mainly distributed from the potomedullary junction to the rostral medulla in the rostro-caudally RF levels, for example, nucleus of reticularis (n. r.) pontis oralis, locus coeruleus, n. r. pontis caudalis, n. r. pars gigantocellularis, n. r. gigantocellularis and n. r. parvocellualris. Reticulocerebellar labeling by the WGA- HRP was found in the same place as well as that of the BDA-projection. We observed that the proportion and location of double labeling cells in the chicken were almost similar in each level, comparing to the rodents. These results suggest that the reticular formation is strongly related to the spicoreticulocerebellar tract in chickens.
Afferent Pathways/physiology ; Animals ; Biotin/*analogs&derivatives ; Cerebellum/anatomy&histology/*physiology ; Chickens/*anatomy&histology/*physiology ; Dextrans ; Efferent Pathways/physiology ; Microinjections ; Reticular Formation/anatomy&histology/*physiology ; Spinal Cord/anatomy&histology/*physiology ; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate

Cerebellum is a key structure involved in motor learning and coordination. In animal models, motor skill learning increased the volume of molecular layer and the number of synapses on Purkinje cells in the cerebellar cortex. The aim of this study is to investigate whether the analogous change of cerebellar volume occurs in human population who learn specialized motor skills and practice them intensively for a long time. Magnetic resonance image (MRI)-based cerebellar volumetry was performed in basketball players and matched controls with V-works image software. Total brain volume, absolute and relative cerebellar volumes were compared between two groups. There was no significant group difference in the total brain volume, the absolute and the relative cerebellar volume. Thus we could not detect structural change in the cerebellum of this athlete group in the macroscopic level.
Neuronal Plasticity ; Motor Skills/physiology ; Models, Anatomic ; Male ; Magnetic Resonance Imaging ; Humans ; Cerebellum/*anatomy & histology/physiology ; Basketball/*physiology ; Animals ; Adult