Staci Sawyer

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Intracellular recordings were obtained in vivo from neurons of the rat substantia nigra, pars compacta. Neurons that were identified as dopaminergic by a variety of electrophysiological criteria, including antidromic activation from ipsilateral neostriatum or globus pallidus, were microiontophoretically injected with horseradish peroxidase and examined at(More)
The goal of this study was to clarify the role of the nucleus accumbens septi (NAS) in the expression of cocaine self-administration behaviors. Rats were trained in a continuous reinforcement schedule to press a lever to activate a pump that provided an intravenous injection of cocaine. Once the rats were trained, neuronal activity in the NAS was monitored(More)
In vivo intracellular recordings were obtained from identified thalamocortical neurons in the ventroanterior-ventrolateral complex in urethane-anesthetized rats. This thalamic nucleus has few interneurons. Neurons that responded to cerebellar stimulation were injected intracellularly with horseradish peroxidase or biocytin and examined with light and(More)
A light and electron microscopic study of GABA-immunoreactive neurons and profiles in the ventroanterior-ventrolateral and ventromedial nuclei of rat dorsal thalamus was conducted using antiserum raised against GABA. Less than 1% of the neurons in these motor-related nuclei exhibited GABA immunoreactivity, confirming previous reports that these nuclei are(More)
Mesencephalic dopaminergic neurons were electrophysiologically identified by a variety of criteria, including antidromic activation from prefrontal or cingulate cortex, neostriatum, or nucleus accumbens in urethane-anesthetized rats. The mean firing rate of 98 mesocortical dopaminergic neurons was 2.9 +/- 0.3 spikes/sec and did not differ from the mean(More)
Chronic single neuronal recording techniques were applied to investigate the involvement of the medial prefrontal cortex (mPFC) during cocaine self-administration in the rat. Rats were trained to press a lever for cocaine under continuous reinforcement and fixed ratio schedules. Different patterns of phasic neuronal activity changes were found to be(More)
Three types of neurons, distinguished on the basis of their spontaneous firing rates and patterns, extracellularly recorded waveforms and responses to neostriatal stimulation, were observed in the dorsal raphe nucleus in urethane-anesthetized rats. Type 1 neurons (presumed to be serotonergic) fired spontaneously from 0.1 to 3 spikes/s in a regular pattern,(More)
Measurement of drug- and stimulation-induced changes in the electrical excitability of dopaminergic terminals was employed to assess the effects of stimulation of dopamine terminal autoreceptors in the prefrontal cortex in urethane-anesthetized rats. Systemic or local administration of amphetamine decreased, whereas systemic administration of haloperidol(More)
A Golgi study of neurons in the ventroanterior-ventrolateral complex (VAL) and ventromedial (VM) nucleus in the dorsal thalamus of rats was performed. To facilitate the delineation of subdivisions of these nuclei, some animals received injections of horseradish peroxidase (HRP) into the afferent and efferent fields of VAL and VM, and alternate sections were(More)
The effects of the potassium channel blockers, 4-aminopyridine (4-AP) and tetraethylammonium (TEA), on autoreceptor-mediated changes in dopaminergic terminal excitability were examined in urethane-anesthetized rats. Local infusions of 4-AP or TEA into neostriatal terminal fields of nigral dopaminergic neurons led to marked decreases in terminal(More)