Biomaterial Database

The organisation of the efferent projections of the zona incerta. 1985

C A Romanowski, and I J Mitchell, and A R Crossman

Department of Anatomy, Manchester.

The hypothesis that the six cytoarchitectonically distinct subdivisions of the zona incerta send efferent projections to different parts of the brain was tested using retrograde fluorescent tracing techniques. Injections of tracer in the superior colliculus, pontomesencephalic tegmentum, thalamus or spinal cord resulted in characteristic and distinctive patterns of labelling in the zona incerta, suggesting that the different subdivisions of the zona incerta give rise to different sets of efferent projections. Thus, injections into the deep layers of the superior colliculus resulted in retrogradely labelled neurons predominantly in the zona incerta pars ventralis, whereas injections into the pontomesencephalic tegmentum, avoiding the superior colliculus, labelled neurons mostly in the zona incerta pars dorsalis. Parafascicular thalamic injections resulted in labelled neurons in the zona incerta pars rostropolaris, pars dorsalis, pars caudalis and a few in the pars ventralis. The spinal cord injections labelled predominantly the magnocellular cells of the zona incerta. The results of the double labelling experiment also give support to the conclusion that different areas of the zona incerta give rise to largely individual sets of efferent projections. Combined injections of tracers into the superior colliculus and thalamus resulted in the labelling of two essentially independent cell groups, the tectal projecting cells being found mainly in the zona incerta pars ventralis and the thalamic projecting cells being found in the zona incerta pars rostropolaris, pars dorsalis and pars caudalis. However, a small number of double labelled cells was found. These cells, which presumably send collateral projections to both the tectum and the thalamus, were found mainly in the dorsal part of the zona incerta pars ventralis, immediately next to the pars dorsalis. In the light of these findings it would appear that the zona incerta may be organised into largely distinct subdivisions, each of which has its own set of cytoarchitectonic and efferent projection characteristics.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008636	Mesencephalon	The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems.	Midbrain,Mesencephalons,Midbrains
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D009476	Neurons, Efferent	Neurons which send impulses peripherally to activate muscles or secretory cells.	Efferent Neurons,Efferent Neuron,Neuron, Efferent
D011149	Pons	The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.	Pons Varolii,Ponte,Pons Varolius,Pontes,Varolii, Pons,Varolius, Pons
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D004027	Diencephalon	The paired caudal parts of the PROSENCEPHALON from which the THALAMUS; HYPOTHALAMUS; EPITHALAMUS; and SUBTHALAMUS are derived.	Interbrain,Interbrains
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013116	Spinal Cord	A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.	Coccygeal Cord,Conus Medullaris,Conus Terminalis,Lumbar Cord,Medulla Spinalis,Myelon,Sacral Cord,Thoracic Cord,Coccygeal Cords,Conus Medullari,Conus Terminali,Cord, Coccygeal,Cord, Lumbar,Cord, Sacral,Cord, Spinal,Cord, Thoracic,Cords, Coccygeal,Cords, Lumbar,Cords, Sacral,Cords, Spinal,Cords, Thoracic,Lumbar Cords,Medulla Spinali,Medullari, Conus,Medullaris, Conus,Myelons,Sacral Cords,Spinal Cords,Spinali, Medulla,Spinalis, Medulla,Terminali, Conus,Terminalis, Conus,Thoracic Cords