Brain atlases have been created across species from flies to humans in order to obtain a better understanding of neuroanatomical morphology. Although these brain atlases allow for analysis of neuroanatomy they do not give insight about how the morphology adapt to fit challenges brought on by unique environments. Here I developed a brain atlas for Astyanax mexicanus, a species known to have populations that differ in various behaviors, to gain a better understanding about how populations of the same species, derived from different environments, evolve to be best suited for the challenges they face. By creating a brain atlas for adult surface fish and three populations of cavefish I was able to examine differences in neuroanatomical structures implicated in regulating behavior. My findings show significant differences in neuroanatomical regions known to regulate behavior. Along with these findings, the brain atlases created are a tool for researches to use and expand on in the future. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Thesis (M.S.)--University of Michigan, 1985.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 128-140). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Michigan, 1985.

M.Sc. / Please refer to full text to view abstract

Call number: LD2668 .T4 1961 R43

Call number: LD2668 .T4 1959 R37

Ph.D., Faculty of Science, University of the Witwatersrand, 2011 / Mole rats are a unique family of the rodent order and are known for a subterranean lifestyle, reduced eye size, regressed visual system and unusual patterns of circadian rhythmicity (co-existence of rhythmic and arrhythmic chronotypes within a species has been documented). Such dramatic changes especially that of phenotype, may lead to the prediction of significant differences in organisation of the brain and physiology, therefore these unusual phenotypic features form the core rationale providing the impetus for the present series of studies. Neuroanatomical examination of the mole rat brain for immunohistochemical markers of the cholinergic, catecholaminergic, serotonergic, orexinergic, and histaminergic systems revealed neuronal organisation that was remarkably similar to those previously reported in other rodents and mammals, despite the notable differences in lifestyle and phenotype. These results indicate a strong phylogenetic constraint acting at the systems level of neuronal organisation. The study of sleep and wake in rhythmic and arrhythmic chronotypes of a species of mole rat indicated the arrhythmic chronotype spent more time awake with a longer average duration of a waking episode and less time in sleep with a shorter average duration of a SWS episode. While remaining somewhat similar between mole rat chronotypes, total sleep time in the mole rats was significantly reduced in comparison to other rodents. These results also indicate independence of circadian rhythmicity and sleep homeostasis and possible alteration of specific genes involved in the sleep-wake cycle of the mole rats examined. Stereological assessment of absolute numbers of orexinergic neurons revealed that the arrrhythmic chronotype tends to have more orexinergic neurons per gram of body mass that the rhythmic chronotype, leading to the conclusion that enhanced vigilance and peripheral metabolism of the arrhythmic chronotype may underlie this difference. Immunohistochemical identification of nuclei involved with the sleep-wake cycle, showed no difference in the distribution of these nuclei between circadian chronotypes and no major differences when compared to other rodents. Some interesting and potentially functionally important homogeneities were observed in the distribution of GABAergic interneurons within the pontine region. Furthermore differential orexinergic terminal network densities were observed between chronotypes within the arcuate nucleus and the intergeniculate leaflet. Therefore despite unusual features in lifestyle and phenotype, the organisation of the mole rat brain remains remarkably similar to other rodents; however, distinctions of circadian chronotype consistently produced subtle differences in both the anatomy and physiology of these rodents.

The etiology of Tourette syndrome has been elusive for researchers ever since its discovery, making treatment especially difficult. After proving the disorder was organic in the second half of the 20th century, researchers have been creating theories of the underlying neural basis for Tourette’s symptomatology. These theories include abnormalities in brain structure, dysregulation of the dopamine system, dysregulation of the serotonin system and overall neurotransmitter system interactions. The etiology is likely a complex combination of all of these. Treatments for this disorder include pharmacological, behavioral and surgical. I believe the best approach for treatment is behavioral first, followed by pharmacological if behavioral does not work, and then surgical as a last resort if the previous two do not show results.

Thesis (Ph. D.)--Leland Stanford Jr. University. / Cover title. Reprinted from Archiv. für die ges. physiologie, bd. 101; and American Journal of Physiology, vol. X, no. 7.