Overinhibition of corticostriatal activity following prenatal cocaine exposure
Article first published online: 7 DEC 2012
Copyright © 2012 American Neurological Association
Annals of Neurology
Volume 73, Issue 3, pages 355–369, March 2013
How to Cite
Wang, W., Nitulescu, I., Lewis, J. S., Lemos, J. C., Bamford, I. J., Posielski, N. M., Storey, G. P., Phillips, P. E. M. and Bamford, N. S. (2013), Overinhibition of corticostriatal activity following prenatal cocaine exposure. Ann Neurol., 73: 355–369. doi: 10.1002/ana.23805
- Issue published online: 17 APR 2013
- Article first published online: 7 DEC 2012
- Accepted manuscript online: 9 NOV 2012 01:00PM EST
- Manuscript Accepted: 29 OCT 2012
- Manuscript Revised: 14 OCT 2012
- Manuscript Received: 11 JUN 2012
- University of Washington Alcohol and Drug Abuse Institute (G.P.S., and N.S.B.). Grant Number: NIH NINDS NS052536 (N.S.B.), NIH NINDS NS060803 (N.S.B.), NIH NINDS NS060803-2S1
- N.S.B., I.N., and N.M.P.. Grant Number: NIH NICHD HD02274
- Mary Gates Endowment for Students research scholarship (I.N., and J.S.L.). Grant Number: NIH NIMH F31MH08626
Prenatal cocaine exposure (PCE) can cause persistent neuropsychological and motor abnormalities in affected children, but the physiological consequences of PCE remain unclear. Conclusions drawn from clinical studies can sometimes be confounded by polysubstance abuse and nutritional deprivation. However, existing observations suggest that cocaine exposure in utero, as in adults, increases synaptic dopamine and promotes enduring dopamine-dependent plasticity at striatal synapses, altering behaviors and basal ganglia function.
We used a combination of behavioral measures, electrophysiology, optical imaging, and biochemical and electrochemical recordings to examine corticostriatal activity in adolescent mice exposed to cocaine in utero.
We show that PCE caused abnormal dopamine-dependent behaviors, including heightened excitation following stress and blunted locomotor augmentation after repeated treatment with amphetamine. These abnormal behaviors were consistent with abnormal γ-aminobutyric acid (GABA) interneuron function, which promoted a reversible depression in corticostriatal activity. PCE hyperpolarized and reduced tonic GABA currents in both fast-spiking and persistent low-threshold spiking type GABA interneurons to increase tonic inhibition at GABAB receptors on presynaptic corticostriatal terminals. Although D2 receptors paradoxically increased glutamate release following PCE, normal corticostriatal modulation by dopamine was reestablished with a GABAA receptor antagonist.
The dynamic alterations at corticostriatal synapses that occur in response to PCE parallel the reported effects of repeated psychostimulants in mature animals, but differ in being specifically generated through GABAergic mechanisms. Our results indicate approaches that normalize GABA and D2 receptor-dependent synaptic plasticity may be useful for treating the behavioral effects of PCE and other developmental disorders that are generated through abnormal GABAergic signaling. ANN NEUROL 2013;73:355–369