In the next funding peroid, we will continue to use modern neurtoanatomical methods to analyze, in significant detail, the organization of extrageniculate visual pathways in mammals. Cats, monkeys, and rats will be primary experimental animals; however, other animals may be used for comparative studies. Specifically, the major thrust of our research endeavors will focus upon defining the basic connections of the pretectal complex. Thus, we are presently engaged in defining the efferent systems of the complex especially with regard to brainstem and thalamic oculomotor centers. Concurrently, we are also examining the neurotransmitters localized within pretectal neurons and/or terminals within the complex by use of immunoreactivity to specific compounds. To date, we have used the presence of acetylcholinesterase and glutamic acid decarboxylase immunoreactivity to identify pretectal systems which may use cholinergic and gamma-aminobutyric acid transmitters, respectively. We plan to extend the transmitter studies to include an analysis of enkephalin, dynorphin, and somatostatin immunoreactivity within the pretectal complex. Double label experiments will also be conducted in order to relate these neurotransmitters with specific afferent and efferent systems. I also plan to continue to study the connections of visual centers which are closely related to the pretectal complex. Such areas include the retina, the superior colliculus, regions of the neocortex, the lateral posterior nucleus of the thalamus, and certain cranial nerve nuclei which receive an input from the pretectum. Detailed data regarding important midbrain visual centers such as the pretectum will, in turn, reveal something about their role in vision as well as overall brain function.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003731-08
Application #
3258155
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1981-05-01
Project End
1991-04-30
Budget Start
1989-05-01
Budget End
1990-04-30
Support Year
8
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Tulane University
Department
Type
Schools of Medicine
DUNS #
City
New Orleans
State
LA
Country
United States
Zip Code
70118
Chen, I L; Weber, J T; Rieck, R W et al. (1992) Synaptic connections of central carotid sinus afferents in the nucleus of the tractus solitarius of the rat. I. An electron microscopic study. J Neurocytol 21:137-47
Harting, J K; Van Lieshout, D P; Hashikawa, T et al. (1991) The parabigeminogeniculate projection: connectional studies in eight mammals. J Comp Neurol 305:559-81
Harting, J K; Huerta, M F; Hashikawa, T et al. (1988) Neuroanatomical studies of the nigrotectal projection in the cat. J Comp Neurol 278:615-31
Gould 3rd, H J; Weber, J T; Rieck, R W (1987) Interhemispheric connections in the visual cortex of the squirrel monkey (Saimiri sciureus). J Comp Neurol 256:14-28
Rieck, R W; Huerta, M F; Harting, J K et al. (1986) Hypothalamic and ventral thalamic projections to the superior colliculus in the cat. J Comp Neurol 243:249-65
Hartwich-Young, R; Weber, J T (1986) The projection of frontal cortical oculomotor areas to the superior colliculus in the domestic cat. J Comp Neurol 253:342-57
Weber, J T; Giolli, R A (1986) The medial terminal nucleus of the monkey: evidence for a 'complete' accessory optic system. Brain Res 365:164-8
Weber, J T (1985) Pretectal complex and accessory optic system of primates. Brain Behav Evol 26:117-40
Hutchins, B; Weber, J T (1985) The pretectal olivary nucleus of the cat: evidence for a two-tailed structure. Brain Res 331:150-4
Hutchins, B; Weber, J T (1985) The pretectal complex of the monkey: a reinvestigation of the morphology and retinal terminations. J Comp Neurol 232:425-42