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Effect of nicotine on dynamic function of brain catecholamine neurons
T H Svensson1, J Grenhoff, G Engberg
1Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Ciba Foundation Symposium
|January 1, 1990
Summary
Nicotine facilitates burst firing in dopamine neurons, potentially aiding conditions like schizophrenia and alcoholism. It also activates noradrenaline neurons, suggesting a rapid coping mechanism relevant to nicotine dependence.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- Mesolimbocortical dopamine (DA) neurons in the ventral tegmental area (VTA) exhibit burst firing, influenced by nicotine.
- Prefrontal cortex (PFC) excitatory drive is crucial for VTA-DA cell bursting.
Purpose of the Study:
- To investigate the role of PFC in VTA-DA neuron bursting and nicotine's effects.
- To explore nicotine's impact on noradrenaline neurons in the locus ceruleus (LC).
Main Methods:
- Systemic nicotine administration.
- Pharmacological manipulations.
- Cold inactivation of the medial prefrontal cortex.
- Physiological recordings of neuronal activity.
Main Results:
- Nicotine facilitates VTA-DA neuron burst firing, dependent on excitatory amino acid drive from the PFC.
- PFC inactivation induced pacemaker-like firing in VTA-DA cells, partially reversed by nicotine.
- Nicotine indirectly activates noradrenaline neurons in the LC, suggesting a rapid, dose-dependent effect.
Conclusions:
- Nicotine may restore VTA-DA system dynamics in hypofrontality-associated disorders like schizophrenia and alcoholism.
- Nicotine's activation of LC noradrenaline neurons could be an instant coping response relevant to nicotine dependence, especially in depression.