Field potential recording in the ventral tegmental area: pharmacological and toxicological evaluations of postsynaptic dopaminergic neuron activity.
Addictive drugs and psychologic stress influence the input strength of ventral tegmental area (VTA) neurons, which implies the involvement of synaptic plasticity in dopaminergic neurons. Properties of excitatory synaptic transmission to the dopaminergic neurons have been analyzed using intracellular and patch-clamp recording methods. In the present study, we attempted to establish the field recording procedure in VTA slice preparations to monitor excitatory synaptic transmission. We evaluated this procedure using slice preparations from 6-hydroxydopamine (6-OHDA)-treated animals. In horizontal slices containing the VTA, electrical stimulation of anterior afferent fibers produced two distinct negative field potentials, presumably a fiber volley component and a transsynaptic component. Pharmacological analysis revealed that the transsynaptic component was composed of bicuculline-sensitive and CNQX-sensitive components. Neonatal 6-OHDA administration reduced approximately 90% of tyrosine hydroxylase expression in the VTA and eliminated more than 50% of the transsynaptic components. This result suggests that at least 50% of the observed transsynaptic component reflected the postsynaptic responses of the dopaminergic neurons.
Zheng
Yingjun
Y
Department of Molecular Neurobiology, Brain Research Institute, Niigata University, 1-757 Asahimachi, Niigata 951-8585, Japan.
Sudou
Kousuke
K
Nawa
Hiroyuki
H
Namba
Hisaaki
H
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D004298:Dopamine / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009924:Organ Culture Techniques; D016627:Oxidopamine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D013565:Sympatholytics / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D013565:Sympatholytics; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D016627:Oxidopamine; D004298:Dopamine