Altered Sensitivity of Recognition Sites for a Neurotransmitter in the Absence of Changes in Receptor Binding Parameters: Co-Sensitization of an Alternate System
During a period of about 5 years we have attempted to permanently modify the organization of different components of the dopamine (DA) neurotransmitter system in the brain. As part of this approach rats have been treated either as neonates or adults with DA receptor agonists, DA receptor antagonists or overt DA neurotoxins. In several instances we successfully attenuated the neuroteratogenic effects of these agents. And as a continuum of these studies we have ascertained that another neurotransmitter system, serotoninergic, actually mediates supersensitization of DA systems. While the study of DA and other neurotransmitter systems may seem remote from the symposium objectives, there are common themes with the neural adaptation and neural mediation that can be expected when botulinum and tetanus neurotoxins exert their effects. As important, is the message that simple measurements of presynaptic and postsynaptic elements (e.g., receptor site status and second messenger changes) are simply inadequate for determining the functional changes that are consequent to the injury produced by these neurotoxins.
KeywordsStriatal Dopamine Behavioral Sensitivity Saline Control Group Postnatal Ontogeny Oral Activity
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