Background and purpose. Recent studies have shown that the children with severe nocturnal enuresis, or bedwetting, often have underlying bladder dysfunction as well as various types of brainstem disorders, including arousal inability, a deficient response to startle sounds, or prepulse inhibition. Since the pontine micturition centre is anatomically very close, even overlapping with the nuclei responsible for sleep arousal, one may speculate that there may be close inter-relationships between abnormal bladder function, brainstem dysfunction and sleep-arousal disturbance. We hypothesize that the brainstem function would be changed in response to alteration of bladder function. Using conventional-fill cystometric study, functional magnetic resonance imaging (fMRI) scanning and immunohistochemistry approaches, we propose to characterize the functional changes in the brainstem in response to altered bladder function (i.e. surgically reduced bladder capacity). / Conclusions. Our results showed that bladder dysfunction elicited by surgical reduction in bladder capacity can induce functional changes in the central nervous system. In response to surgical reduction in bladder capacity, deactivation in the vlPAG was detected suggesting that the vlPAG plays a role in the biofeedback of bladder dysfunction. / Data are expressed as the mean +/-1SD unless otherwise specified. Appropriate statistical tests were used for parametric and non-parametric testing between the groups by using the SPSS computer program. In all comparisons a statistical significance level of 95% (p<0.05) was chosen. / Immunohistochemistry study showed a significant decrease in the reaction of dopaminergic neuron in the correspondent regions, suggesting a dopaminergic dependent change in the vlPAG in response to the bladder dysfunction. / In addition, we will explore the use of electroacupuncture (EA), a traditional Chinese therapy that has been broadly used for treatment of bladder functional disorders, to modulate functional changes in the central nervous system. We hypothesize that functional change in various nuclei in the central nervous system that are responsible for micturition control can also be affected by acupuncture treatment. A further aim of this study was to identify brain areas involved in EA to acupoint Chiliao (BL 32), a special acupoint broadly used for the treatment of bladder disorders. / Materials and methods. The study was divided into four parts. Seventy-five male New Zealand white rabbits (14-16 weeks, mean body weight: 3.0-3.5 kg) were used. / Moreover, in this study, we also found a notable activation in the vlPAG and dlPONS in response to the acupuncture stimulations to acupoint Chiliao (BL 32). The changes were identical to that induced by the bladder distension, suggesting a neuromodulation in central nervous system in response to acupuncture therapy. / Results. Study I: Bladder dysfunction elicited by surgical reduction in bladder capacity. Compared to sham animals, the maximum cystometric capacity in animals with RBC operation was markedly decreased at week 4 (35.3+/-8.2 ml vs. 71.6+/-12.9 ml, p<0.05), and week 8 (46.2+/-12.1ml vs. 82.7+/-20.1 ml, p<0.05) groups respectively; however, the maximum voiding detrusor pressure was significantly increased at week 4 (24.4+/-7.0 vs.16.5+/-7.2 cm water, p<0.05) and week 8 (27.7+/-8.p vs. 16.8+/-7.5 cm water, p<0.05) groups respectively, and their corresponding vesical pressure was also enhanced. Other parameters including maximum flow rate, and bladder emptying efficiency did not change significantly in between the sham and RBC subgroups. / Study I: Establishment of the dysfunctional bladder animal model with small bladder capacity. Forty rabbits underwent either sham operation (n=20) or operation for reduced bladder capacity (RBC) (n=20). The sham-operated and the RBC animals were further divided into two groups, i.e. four, and eight weeks after operation (n=10 in each sham and RBC subgroup). A conventional-fill cystometric study was performed on these animals whilst awake in order to evaluate the functional changes (if any) in response to surgical bladder capacity reduction, compared to sham subgroup. / Study II: Detection of functional changes in the brainstem in response to bladder dysfunction. FMRI scanning was performed at the brainstem region in sham-operated and RBC rabbits (12 in each group) at four weeks postoperatively. Bladder stimulation was provided by warm saline (37°C) infusion through a urethral catheter until bladder distended to 70% of the maximum capacity. Area(s) of brainstem activation were assessed by comparing the fMRI scans performed before and after warm saline infusion. / Study II: Functional changes in brainstem in response to bladder dysfunction. FMRI scanning results demonstrated that for the sham animals, there were two activated regions in the brainstem in response to bladder distention, one in the ventrolateral region of periaqueductal gray (vlPAG, 83.3%, 10/12), and the other in the dorsolateral region of pons (dlPONS, 91.7%, 11/12). In animals with RBC operation, only 25% (3/12) showed vlPAG activation compared to 83.3% (10/12) in sham group (p<0.05); however, 83.3% (10/12) of animals showed similar dlPONS activation compared to 91.7% in sham group (p>0.05). / Study III: Catecholaminergic neurotransmitters changes in the brainstem affected areas in response to bladder dysfunction. Brainstem immunohistochemistry results showed that a large number of dopaminergic neuron scattered throughout the whole vlPAG, rarely appeared in dlPAG (dorsolateral region of periaqueductal gray) (lambda +6.0 to +3.0 mm); and an abundant noradrenergic neurons were also accumulated in a restricted region of dlPONS (lambda +3.0 to 0 mm). Compared with the sham group, the density of TH-positive neurons in the vlPAG was significantly decreased in RBC group (38.38+/-4.71 vs.51.57+/-8.38/field, p<0.05); for the another region of dlPONS, although the density of TH-positive neurons decreased slightly in RBC group compared to sham group, the results showed no statistical difference between groups (106.89 +/- 21.61 vs.120.61 +/- 17.03/field, p>0.05). / Study III: Investigation of the catecholaminergic neurotransmitters changes in brainstem affected areas in response to bladder dysfunction. After fMRI examination, all animals were euthanized, and their brainstems were collected for immunohistochemistry study with tyrosine hydroxylase, dopamine-beta-hydroxylase assays to investigate the changes of catecholaminergic neurotransmitters including dopaminergic, noradrenergic and adrenergic in response to bladder dysfunction elicited by surgical reduction in bladder capacity. / Study IV: Electroacupuncture modulation via acupoint Chiliao (BL 32) on bladder and the brainstem activated sites. FMRI study showed that the two brainstem micturition centers of the vlPAG (72.7%, 8/11) and dlPONS (82.8%, 9/11) can be activated by EA on BL 32, and there were no significant difference compared with stimulation of bladder distention (72.7% vs. 83.3% in vlPAG and 82.8% vs. 91.7% in dlPONS respectively, p>0.05). Urodynamic results showed that, bladder contraction obviously evoked in response to EA on BL 32 (ON-EA state) compared to before EA state (OFF-EA state), displaying a significantly increased detrusor pressure (14.04+/-3.17 vs. 8.19+/-0.69 cm water, p<0.05) and vesical pressure (13.48+/-1.61vs. 7.90+/-0.81 cm water, p<0.05). In addition, dissection of BL 32 showed that the stem of S1 and S2 pass through the region 0.5 cm around the acupuncuture needle. / Study IV: Investigation of electroacupuncture modulation via acupoint Chiliao (BL 32) on bladder and the brainstem activated sites. FMRI scanning and urodynamic evaluation were performed respectively during ON/OFF EA on acupoint Chiliao (BL 32) on sham-operated animals (n=12) at four weeks post-operation. At last, dissection of acupoint BL 32 was performed on seven sham animals. / We also found that surgically induced bladder dysfunction, mainly displaying as reduced bladder capacity and maximum voiding detrusor pressure enhanced, was elicited at four to eight weeks after the surgical reduction in bladder capacity in rabbit. / Xiang Bo. / "August 2006." / Adviser: Chung Kwong Yeung. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1551. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 161-196). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.

published_or_final_version / abstract / Paediatrics and Adolescent Medicine / Master / Master of Philosophy

published_or_final_version / abstract / Physiology / Master / Master of Philosophy

Previous work relating postmortem findings with cause of death have focused on the vitreous portion of the body. This research investigated the link between phospholipids in the brainstem and cause of death. The lipids were extracted by the Folch extraction method and then separated by High Performance Thin Layer Chromatography. These techniques gave excellent separation and resolution. Results showed no link between cause of death and the type of lipids found in the brainstem after death.

This dissertation is the documentation for a Doctoral research program undertaken at the Industrial Research Institute of the Swinburne University of Technology (IRIS), in collaboration with the School of Biophysical Sciences and Electrical Engineering (BSEE), between the years of 2000 and 2004. The objective of the research work that was undertaken was to study the auditory brainstem response (ABR) characteristics of people with Parkinson�s Disease (PD) to determine whether or not these characteristics could form the basis of a tool for determining the presence of PD; the performance of medication, and disease progression. Prior to the commencement of this research, the gold-standard for PD diagnostics was considered to be autopsy, and the only tools available for assessment of living patients were fluoro-deoxyglucose (FDG) / fluoroDopa (FDopa)-based positron emission tomography (PET) or conventional (subjective) clinical testing. The use of PET was costly and impractical for monitoring disease progression. Clinical testing approaches, on the other hand, had a degree of subjectivity, leading to potential misdiagnoses with inadequately trained clinicians. It was therefore postulated that a low-cost technique based on conventional ABR testing equipment, which was readily available within the medical environment, could provide considerable benefits. In order to be useful as a tool, ABR would ultimately need to identify uniquely the presence of PD from other potential disorders, most notably multiple system atrophy (MSA) which was sometimes confused with PD. At the time this research was conducted, the prevailing method of differentiating PD from MSA was based upon magnetic resonance imaging (MRI). This research was only concerned with the first stage of such a research process � that is, determining whether the ABR of PD patients was fundamentally different to that of a control group. In undertaking the investigation, a significant component of the research involved drawing together research literature from a large number of sources in order to present a case that could present a reasonable research path for experimentation. The next stage of the research involved developing an experimentation program that could be used to compare the ABR characteristics of people with PD against a control group and, further, to compare the ABR characteristics of PD participants against their level of impairment, as measured on a conventional mobility test. In summary, the outcomes of the experimental process that was undertaken, and the statistical analysis of the outcomes, suggested that: (1) People with mild manifestations of PD, who were in an unmedicated state, had marked abnormalities in the amplitude of Wave III of their ABR waveform. (2) The amplitude of Wave III of the ABR waveform was sensitive to variations in PD medication levels. (3) The amplitude of Wave V of the ABR waveform was, to a lesser extent than Wave III, affected by the presence of PD and medication levels. (4) The latencies of Waves III and V of the ABR waveforms did not appear to be affected by the presence of PD or by variations in medication levels. This thesis presents the results of the experimental study, together with a statistical analysis of the significance of the outcomes and an evaluation of the limitations of the work that was carried out. The recommendations arising from the research outcomes suggest ways for extending the work that has been completed in this program.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (D. Phil. Communication Pathology)--Universiteit van Pretoria, 2002. / Summary in English and Afrikaans. Includes bibliographical references.

No description available.

The work reported here was aimed at extending previous findings suggesting that the medial and lateral substantia nigra (SN) are functionally different with regard to intracranial self-stimulation (ICSS) and circling. It was found that the effects of systemic D- and L-amphetamine on ICSS were different for medial and lateral SN sites. These differences were attributed to the presence of two subtypes of dopamine (DA) neurons in the SN. The circling results indicate that circling in opposite directions can be elicited from the medial and lateral parts of the nigrostriatal DA system from the same hemisphere suggesting that medial and lateral nigrostriatal DA have opposing roles in the expression of circling. It was further demonstrated that the superior colliculus is critical for the expression of medial SN derived circling and the midbrain reticular formation is critical for both medial and lateral SN derived circling.