Thesis (Ph. D.)--University of Sydney, 2007. / Cotutelle thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Pharmacology, Faculty of Medicine, University of Sydney and to the Doctoral School: Santé, Sciences et Technologies, University of Tours (France). Title from title screen (viewed Sept. 21, 2007). Includes bibliography. Also issued in print.

Thesis (Ph.D.)--Uppsala Universitet, 2009. / This website links to the complete document in PDF format. Title from title screen (viewed on November 21, 2009). Includes bibliographical references.

Animals respond to changes in the environment and internal states to modify their behavior. The basal ganglia, including the striatum contribute to action selection by integrating sensory, motor and reward information. Therefore, dysregulation of striatal function is common in many neuropsychiatric disorders, including Parkinson’s disease, Huntington disease, schizophrenia, and addiction. Here, using fiber photometry, pharmacology, and behavioral approaches in transgenic mice, I explored the cellular and circuit mechanisms underlying key striatal functions. In Chapter 1, I begin by presenting the existing literature on the anatomy and physiology of the striatum. Next, I review the important functions of the striatum. Within this general review, I highlight the specific roles that striatal (DA) and acetylcholine (ACh) play in striatal circuitry and function. In Chapter 2, I demonstrate the naturally evoked ACh dip has a DA component and a non-DA component. Specifically, I show that DA via cholinergic DA D2 receptors (D2Rs) modulate the length of the ACh dip and rebound ACh levels following the dip. In addition, I show that DA coordinates the activity between DA and ACh during behavior. Finally, I present data that supports a role for ACh in motivated behavior. In Chapter 3, I show that cholinergic D2Rs are not necessary for reward learning but do facilitate reversal learning in a probabilistic choice task. In addition, I show that changes in DA and ACh levels contribute to reversal learning in a probabilistic choice task. Finally, in Chapter 4, I discuss the general conclusions and study implications, as well as future directions.

The reinforcing properties of nicotine depend partly on cholinergic projections from the pedunculopontine tegmental (PPTg) and laterodorsal tegmental (LDTg) nuclei to midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Neuronal activation was investigated using Fos expression in these areas following acute (0, 0.1, 0.4, 0.8mg/kg) or chronic systemic nicotine (0, 0.1, 0.4, 0.8, 1.0mg/kg given once per day for 5 days). We also examined co-localization of Fos expression in bNOS and TH positive neurons to determine what populations of neurons were activated by nicotine. Acute nicotine resulted in dose related Fos expression, with the biggest increase seen after 0.4mg/kg nicotine, but no co-localization occurred with bNOS in the PPTg/LDTg. Surprisingly, nicotine also failed to activate midbrain dopamine neurons. After animals were sensitized to nicotine there was a similar dose response curve in Fos expression, but the biggest increase was seen after 0.8mg/kg nicotine. Chronic nicotine, like acute, also preferentially activated non-cholinergic neurons in the LDTg and PPTg and non-dopamine neurons in the SNc and VTA. Further experiments looked at the mechanisms of Fos expression after nicotine administration. Fos expression in the LDTg/PPTg and SNc/VTA was suppressed after d-amphetamine, despite an increase in locomotor activity, suggesting that the increased Fos expression after chronic nicotine was not simply due to the locomotor activating effects of sensitized nicotine. Blocking autoreceptors in the dopaminergic midbrain by haloperidol pre-treatment did not increase Fos expression in dopamine neurons indicating that the inhibitory mechanism was not dependent on local autoreceptors. Novel methods of visualising and lesioning GABA neurons in the mesopontine tegmentum and midbrain were also examined. The data suggest that the mechanisms by which dopamine is involved in the pharmacological actions of passively administered nicotine are more complex than was first thought and that the role of non-dopamine neurons in the VTA (possibly GABA or glutamate containing) are also important.

Thesis (M.S.)--State University of New York at Binghamton, Department of Psychology, 2009. / Includes bibliographical references.

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Investigations of cholinergic and adrenergic tone on heart rate (fH) and mean arterial pressure (Pm) during embryonic development have been conducted on numerous avian species. While these investigations have documented that adrenergic tone, a continuous stimulation, on fH and Pm is vital to embryonic development in the birds studied to date, development of cholinergic tone on fH has been shown to vary even within species. Further, past studies have been bias to focus primarily on precocial species while altricial species remain poorly understood in this context. The goal of this investigation was to investigate the role of cholinergic and adrenergic tone on fH and Pm of an altricial species, the neotropic cormorant (P. brasilianus) to address this bias. The embryonic neotropic cormorant possesses B-and-a adrenergic tone on fH and Pm at 70% and 90% incubation while cholinergic tone on fH occurs at 90% incubation. This pattern of control is similar to that previously reported for several species of precocial birds suggesting the development of tonic cardiovascular regulation may be conserved across avian taxa.